11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * Routines having to do with the 'struct sk_buff' memory handlers. 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Authors: Alan Cox <iiitac@pyr.swan.ac.uk> 51da177e4SLinus Torvalds * Florian La Roche <rzsfl@rz.uni-sb.de> 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * Version: $Id: skbuff.c,v 1.90 2001/11/07 05:56:19 davem Exp $ 81da177e4SLinus Torvalds * 91da177e4SLinus Torvalds * Fixes: 101da177e4SLinus Torvalds * Alan Cox : Fixed the worst of the load 111da177e4SLinus Torvalds * balancer bugs. 121da177e4SLinus Torvalds * Dave Platt : Interrupt stacking fix. 131da177e4SLinus Torvalds * Richard Kooijman : Timestamp fixes. 141da177e4SLinus Torvalds * Alan Cox : Changed buffer format. 151da177e4SLinus Torvalds * Alan Cox : destructor hook for AF_UNIX etc. 161da177e4SLinus Torvalds * Linus Torvalds : Better skb_clone. 171da177e4SLinus Torvalds * Alan Cox : Added skb_copy. 181da177e4SLinus Torvalds * Alan Cox : Added all the changed routines Linus 191da177e4SLinus Torvalds * only put in the headers 201da177e4SLinus Torvalds * Ray VanTassle : Fixed --skb->lock in free 211da177e4SLinus Torvalds * Alan Cox : skb_copy copy arp field 221da177e4SLinus Torvalds * Andi Kleen : slabified it. 231da177e4SLinus Torvalds * Robert Olsson : Removed skb_head_pool 241da177e4SLinus Torvalds * 251da177e4SLinus Torvalds * NOTE: 261da177e4SLinus Torvalds * The __skb_ routines should be called with interrupts 271da177e4SLinus Torvalds * disabled, or you better be *real* sure that the operation is atomic 281da177e4SLinus Torvalds * with respect to whatever list is being frobbed (e.g. via lock_sock() 291da177e4SLinus Torvalds * or via disabling bottom half handlers, etc). 301da177e4SLinus Torvalds * 311da177e4SLinus Torvalds * This program is free software; you can redistribute it and/or 321da177e4SLinus Torvalds * modify it under the terms of the GNU General Public License 331da177e4SLinus Torvalds * as published by the Free Software Foundation; either version 341da177e4SLinus Torvalds * 2 of the License, or (at your option) any later version. 351da177e4SLinus Torvalds */ 361da177e4SLinus Torvalds 371da177e4SLinus Torvalds /* 381da177e4SLinus Torvalds * The functions in this file will not compile correctly with gcc 2.4.x 391da177e4SLinus Torvalds */ 401da177e4SLinus Torvalds 411da177e4SLinus Torvalds #include <linux/config.h> 421da177e4SLinus Torvalds #include <linux/module.h> 431da177e4SLinus Torvalds #include <linux/types.h> 441da177e4SLinus Torvalds #include <linux/kernel.h> 451da177e4SLinus Torvalds #include <linux/sched.h> 461da177e4SLinus Torvalds #include <linux/mm.h> 471da177e4SLinus Torvalds #include <linux/interrupt.h> 481da177e4SLinus Torvalds #include <linux/in.h> 491da177e4SLinus Torvalds #include <linux/inet.h> 501da177e4SLinus Torvalds #include <linux/slab.h> 511da177e4SLinus Torvalds #include <linux/netdevice.h> 521da177e4SLinus Torvalds #ifdef CONFIG_NET_CLS_ACT 531da177e4SLinus Torvalds #include <net/pkt_sched.h> 541da177e4SLinus Torvalds #endif 551da177e4SLinus Torvalds #include <linux/string.h> 561da177e4SLinus Torvalds #include <linux/skbuff.h> 571da177e4SLinus Torvalds #include <linux/cache.h> 581da177e4SLinus Torvalds #include <linux/rtnetlink.h> 591da177e4SLinus Torvalds #include <linux/init.h> 601da177e4SLinus Torvalds #include <linux/highmem.h> 611da177e4SLinus Torvalds 621da177e4SLinus Torvalds #include <net/protocol.h> 631da177e4SLinus Torvalds #include <net/dst.h> 641da177e4SLinus Torvalds #include <net/sock.h> 651da177e4SLinus Torvalds #include <net/checksum.h> 661da177e4SLinus Torvalds #include <net/xfrm.h> 671da177e4SLinus Torvalds 681da177e4SLinus Torvalds #include <asm/uaccess.h> 691da177e4SLinus Torvalds #include <asm/system.h> 701da177e4SLinus Torvalds 711da177e4SLinus Torvalds static kmem_cache_t *skbuff_head_cache; 721da177e4SLinus Torvalds 731da177e4SLinus Torvalds /* 741da177e4SLinus Torvalds * Keep out-of-line to prevent kernel bloat. 751da177e4SLinus Torvalds * __builtin_return_address is not used because it is not always 761da177e4SLinus Torvalds * reliable. 771da177e4SLinus Torvalds */ 781da177e4SLinus Torvalds 791da177e4SLinus Torvalds /** 801da177e4SLinus Torvalds * skb_over_panic - private function 811da177e4SLinus Torvalds * @skb: buffer 821da177e4SLinus Torvalds * @sz: size 831da177e4SLinus Torvalds * @here: address 841da177e4SLinus Torvalds * 851da177e4SLinus Torvalds * Out of line support code for skb_put(). Not user callable. 861da177e4SLinus Torvalds */ 871da177e4SLinus Torvalds void skb_over_panic(struct sk_buff *skb, int sz, void *here) 881da177e4SLinus Torvalds { 8926095455SPatrick McHardy printk(KERN_EMERG "skb_over_panic: text:%p len:%d put:%d head:%p " 9026095455SPatrick McHardy "data:%p tail:%p end:%p dev:%s\n", 9126095455SPatrick McHardy here, skb->len, sz, skb->head, skb->data, skb->tail, skb->end, 9226095455SPatrick McHardy skb->dev ? skb->dev->name : "<NULL>"); 931da177e4SLinus Torvalds BUG(); 941da177e4SLinus Torvalds } 951da177e4SLinus Torvalds 961da177e4SLinus Torvalds /** 971da177e4SLinus Torvalds * skb_under_panic - private function 981da177e4SLinus Torvalds * @skb: buffer 991da177e4SLinus Torvalds * @sz: size 1001da177e4SLinus Torvalds * @here: address 1011da177e4SLinus Torvalds * 1021da177e4SLinus Torvalds * Out of line support code for skb_push(). Not user callable. 1031da177e4SLinus Torvalds */ 1041da177e4SLinus Torvalds 1051da177e4SLinus Torvalds void skb_under_panic(struct sk_buff *skb, int sz, void *here) 1061da177e4SLinus Torvalds { 10726095455SPatrick McHardy printk(KERN_EMERG "skb_under_panic: text:%p len:%d put:%d head:%p " 10826095455SPatrick McHardy "data:%p tail:%p end:%p dev:%s\n", 10926095455SPatrick McHardy here, skb->len, sz, skb->head, skb->data, skb->tail, skb->end, 11026095455SPatrick McHardy skb->dev ? skb->dev->name : "<NULL>"); 1111da177e4SLinus Torvalds BUG(); 1121da177e4SLinus Torvalds } 1131da177e4SLinus Torvalds 1141da177e4SLinus Torvalds /* Allocate a new skbuff. We do this ourselves so we can fill in a few 1151da177e4SLinus Torvalds * 'private' fields and also do memory statistics to find all the 1161da177e4SLinus Torvalds * [BEEP] leaks. 1171da177e4SLinus Torvalds * 1181da177e4SLinus Torvalds */ 1191da177e4SLinus Torvalds 1201da177e4SLinus Torvalds /** 1211da177e4SLinus Torvalds * alloc_skb - allocate a network buffer 1221da177e4SLinus Torvalds * @size: size to allocate 1231da177e4SLinus Torvalds * @gfp_mask: allocation mask 1241da177e4SLinus Torvalds * 1251da177e4SLinus Torvalds * Allocate a new &sk_buff. The returned buffer has no headroom and a 1261da177e4SLinus Torvalds * tail room of size bytes. The object has a reference count of one. 1271da177e4SLinus Torvalds * The return is the buffer. On a failure the return is %NULL. 1281da177e4SLinus Torvalds * 1291da177e4SLinus Torvalds * Buffers may only be allocated from interrupts using a @gfp_mask of 1301da177e4SLinus Torvalds * %GFP_ATOMIC. 1311da177e4SLinus Torvalds */ 13286a76cafSVictor Fusco struct sk_buff *alloc_skb(unsigned int size, unsigned int __nocast gfp_mask) 1331da177e4SLinus Torvalds { 1341da177e4SLinus Torvalds struct sk_buff *skb; 1351da177e4SLinus Torvalds u8 *data; 1361da177e4SLinus Torvalds 1371da177e4SLinus Torvalds /* Get the HEAD */ 1381da177e4SLinus Torvalds skb = kmem_cache_alloc(skbuff_head_cache, 1391da177e4SLinus Torvalds gfp_mask & ~__GFP_DMA); 1401da177e4SLinus Torvalds if (!skb) 1411da177e4SLinus Torvalds goto out; 1421da177e4SLinus Torvalds 1431da177e4SLinus Torvalds /* Get the DATA. Size must match skb_add_mtu(). */ 1441da177e4SLinus Torvalds size = SKB_DATA_ALIGN(size); 1451da177e4SLinus Torvalds data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask); 1461da177e4SLinus Torvalds if (!data) 1471da177e4SLinus Torvalds goto nodata; 1481da177e4SLinus Torvalds 1491da177e4SLinus Torvalds memset(skb, 0, offsetof(struct sk_buff, truesize)); 1501da177e4SLinus Torvalds skb->truesize = size + sizeof(struct sk_buff); 1511da177e4SLinus Torvalds atomic_set(&skb->users, 1); 1521da177e4SLinus Torvalds skb->head = data; 1531da177e4SLinus Torvalds skb->data = data; 1541da177e4SLinus Torvalds skb->tail = data; 1551da177e4SLinus Torvalds skb->end = data + size; 1561da177e4SLinus Torvalds 1571da177e4SLinus Torvalds atomic_set(&(skb_shinfo(skb)->dataref), 1); 1581da177e4SLinus Torvalds skb_shinfo(skb)->nr_frags = 0; 1591da177e4SLinus Torvalds skb_shinfo(skb)->tso_size = 0; 1601da177e4SLinus Torvalds skb_shinfo(skb)->tso_segs = 0; 1611da177e4SLinus Torvalds skb_shinfo(skb)->frag_list = NULL; 1621da177e4SLinus Torvalds out: 1631da177e4SLinus Torvalds return skb; 1641da177e4SLinus Torvalds nodata: 1651da177e4SLinus Torvalds kmem_cache_free(skbuff_head_cache, skb); 1661da177e4SLinus Torvalds skb = NULL; 1671da177e4SLinus Torvalds goto out; 1681da177e4SLinus Torvalds } 1691da177e4SLinus Torvalds 1701da177e4SLinus Torvalds /** 1711da177e4SLinus Torvalds * alloc_skb_from_cache - allocate a network buffer 1721da177e4SLinus Torvalds * @cp: kmem_cache from which to allocate the data area 1731da177e4SLinus Torvalds * (object size must be big enough for @size bytes + skb overheads) 1741da177e4SLinus Torvalds * @size: size to allocate 1751da177e4SLinus Torvalds * @gfp_mask: allocation mask 1761da177e4SLinus Torvalds * 1771da177e4SLinus Torvalds * Allocate a new &sk_buff. The returned buffer has no headroom and 1781da177e4SLinus Torvalds * tail room of size bytes. The object has a reference count of one. 1791da177e4SLinus Torvalds * The return is the buffer. On a failure the return is %NULL. 1801da177e4SLinus Torvalds * 1811da177e4SLinus Torvalds * Buffers may only be allocated from interrupts using a @gfp_mask of 1821da177e4SLinus Torvalds * %GFP_ATOMIC. 1831da177e4SLinus Torvalds */ 1841da177e4SLinus Torvalds struct sk_buff *alloc_skb_from_cache(kmem_cache_t *cp, 18586a76cafSVictor Fusco unsigned int size, 18686a76cafSVictor Fusco unsigned int __nocast gfp_mask) 1871da177e4SLinus Torvalds { 1881da177e4SLinus Torvalds struct sk_buff *skb; 1891da177e4SLinus Torvalds u8 *data; 1901da177e4SLinus Torvalds 1911da177e4SLinus Torvalds /* Get the HEAD */ 1921da177e4SLinus Torvalds skb = kmem_cache_alloc(skbuff_head_cache, 1931da177e4SLinus Torvalds gfp_mask & ~__GFP_DMA); 1941da177e4SLinus Torvalds if (!skb) 1951da177e4SLinus Torvalds goto out; 1961da177e4SLinus Torvalds 1971da177e4SLinus Torvalds /* Get the DATA. */ 1981da177e4SLinus Torvalds size = SKB_DATA_ALIGN(size); 1991da177e4SLinus Torvalds data = kmem_cache_alloc(cp, gfp_mask); 2001da177e4SLinus Torvalds if (!data) 2011da177e4SLinus Torvalds goto nodata; 2021da177e4SLinus Torvalds 2031da177e4SLinus Torvalds memset(skb, 0, offsetof(struct sk_buff, truesize)); 2041da177e4SLinus Torvalds skb->truesize = size + sizeof(struct sk_buff); 2051da177e4SLinus Torvalds atomic_set(&skb->users, 1); 2061da177e4SLinus Torvalds skb->head = data; 2071da177e4SLinus Torvalds skb->data = data; 2081da177e4SLinus Torvalds skb->tail = data; 2091da177e4SLinus Torvalds skb->end = data + size; 2101da177e4SLinus Torvalds 2111da177e4SLinus Torvalds atomic_set(&(skb_shinfo(skb)->dataref), 1); 2121da177e4SLinus Torvalds skb_shinfo(skb)->nr_frags = 0; 2131da177e4SLinus Torvalds skb_shinfo(skb)->tso_size = 0; 2141da177e4SLinus Torvalds skb_shinfo(skb)->tso_segs = 0; 2151da177e4SLinus Torvalds skb_shinfo(skb)->frag_list = NULL; 2161da177e4SLinus Torvalds out: 2171da177e4SLinus Torvalds return skb; 2181da177e4SLinus Torvalds nodata: 2191da177e4SLinus Torvalds kmem_cache_free(skbuff_head_cache, skb); 2201da177e4SLinus Torvalds skb = NULL; 2211da177e4SLinus Torvalds goto out; 2221da177e4SLinus Torvalds } 2231da177e4SLinus Torvalds 2241da177e4SLinus Torvalds 2251da177e4SLinus Torvalds static void skb_drop_fraglist(struct sk_buff *skb) 2261da177e4SLinus Torvalds { 2271da177e4SLinus Torvalds struct sk_buff *list = skb_shinfo(skb)->frag_list; 2281da177e4SLinus Torvalds 2291da177e4SLinus Torvalds skb_shinfo(skb)->frag_list = NULL; 2301da177e4SLinus Torvalds 2311da177e4SLinus Torvalds do { 2321da177e4SLinus Torvalds struct sk_buff *this = list; 2331da177e4SLinus Torvalds list = list->next; 2341da177e4SLinus Torvalds kfree_skb(this); 2351da177e4SLinus Torvalds } while (list); 2361da177e4SLinus Torvalds } 2371da177e4SLinus Torvalds 2381da177e4SLinus Torvalds static void skb_clone_fraglist(struct sk_buff *skb) 2391da177e4SLinus Torvalds { 2401da177e4SLinus Torvalds struct sk_buff *list; 2411da177e4SLinus Torvalds 2421da177e4SLinus Torvalds for (list = skb_shinfo(skb)->frag_list; list; list = list->next) 2431da177e4SLinus Torvalds skb_get(list); 2441da177e4SLinus Torvalds } 2451da177e4SLinus Torvalds 2461da177e4SLinus Torvalds void skb_release_data(struct sk_buff *skb) 2471da177e4SLinus Torvalds { 2481da177e4SLinus Torvalds if (!skb->cloned || 2491da177e4SLinus Torvalds !atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1, 2501da177e4SLinus Torvalds &skb_shinfo(skb)->dataref)) { 2511da177e4SLinus Torvalds if (skb_shinfo(skb)->nr_frags) { 2521da177e4SLinus Torvalds int i; 2531da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) 2541da177e4SLinus Torvalds put_page(skb_shinfo(skb)->frags[i].page); 2551da177e4SLinus Torvalds } 2561da177e4SLinus Torvalds 2571da177e4SLinus Torvalds if (skb_shinfo(skb)->frag_list) 2581da177e4SLinus Torvalds skb_drop_fraglist(skb); 2591da177e4SLinus Torvalds 2601da177e4SLinus Torvalds kfree(skb->head); 2611da177e4SLinus Torvalds } 2621da177e4SLinus Torvalds } 2631da177e4SLinus Torvalds 2641da177e4SLinus Torvalds /* 2651da177e4SLinus Torvalds * Free an skbuff by memory without cleaning the state. 2661da177e4SLinus Torvalds */ 2671da177e4SLinus Torvalds void kfree_skbmem(struct sk_buff *skb) 2681da177e4SLinus Torvalds { 2691da177e4SLinus Torvalds skb_release_data(skb); 2701da177e4SLinus Torvalds kmem_cache_free(skbuff_head_cache, skb); 2711da177e4SLinus Torvalds } 2721da177e4SLinus Torvalds 2731da177e4SLinus Torvalds /** 2741da177e4SLinus Torvalds * __kfree_skb - private function 2751da177e4SLinus Torvalds * @skb: buffer 2761da177e4SLinus Torvalds * 2771da177e4SLinus Torvalds * Free an sk_buff. Release anything attached to the buffer. 2781da177e4SLinus Torvalds * Clean the state. This is an internal helper function. Users should 2791da177e4SLinus Torvalds * always call kfree_skb 2801da177e4SLinus Torvalds */ 2811da177e4SLinus Torvalds 2821da177e4SLinus Torvalds void __kfree_skb(struct sk_buff *skb) 2831da177e4SLinus Torvalds { 2849c2b3328SStephen Hemminger BUG_ON(skb->list != NULL); 2851da177e4SLinus Torvalds 2861da177e4SLinus Torvalds dst_release(skb->dst); 2871da177e4SLinus Torvalds #ifdef CONFIG_XFRM 2881da177e4SLinus Torvalds secpath_put(skb->sp); 2891da177e4SLinus Torvalds #endif 2901da177e4SLinus Torvalds if (skb->destructor) { 2919c2b3328SStephen Hemminger WARN_ON(in_irq()); 2921da177e4SLinus Torvalds skb->destructor(skb); 2931da177e4SLinus Torvalds } 2941da177e4SLinus Torvalds #ifdef CONFIG_NETFILTER 2951da177e4SLinus Torvalds nf_conntrack_put(skb->nfct); 2961da177e4SLinus Torvalds #ifdef CONFIG_BRIDGE_NETFILTER 2971da177e4SLinus Torvalds nf_bridge_put(skb->nf_bridge); 2981da177e4SLinus Torvalds #endif 2991da177e4SLinus Torvalds #endif 3001da177e4SLinus Torvalds /* XXX: IS this still necessary? - JHS */ 3011da177e4SLinus Torvalds #ifdef CONFIG_NET_SCHED 3021da177e4SLinus Torvalds skb->tc_index = 0; 3031da177e4SLinus Torvalds #ifdef CONFIG_NET_CLS_ACT 3041da177e4SLinus Torvalds skb->tc_verd = 0; 3051da177e4SLinus Torvalds skb->tc_classid = 0; 3061da177e4SLinus Torvalds #endif 3071da177e4SLinus Torvalds #endif 3081da177e4SLinus Torvalds 3091da177e4SLinus Torvalds kfree_skbmem(skb); 3101da177e4SLinus Torvalds } 3111da177e4SLinus Torvalds 3121da177e4SLinus Torvalds /** 3131da177e4SLinus Torvalds * skb_clone - duplicate an sk_buff 3141da177e4SLinus Torvalds * @skb: buffer to clone 3151da177e4SLinus Torvalds * @gfp_mask: allocation priority 3161da177e4SLinus Torvalds * 3171da177e4SLinus Torvalds * Duplicate an &sk_buff. The new one is not owned by a socket. Both 3181da177e4SLinus Torvalds * copies share the same packet data but not structure. The new 3191da177e4SLinus Torvalds * buffer has a reference count of 1. If the allocation fails the 3201da177e4SLinus Torvalds * function returns %NULL otherwise the new buffer is returned. 3211da177e4SLinus Torvalds * 3221da177e4SLinus Torvalds * If this function is called from an interrupt gfp_mask() must be 3231da177e4SLinus Torvalds * %GFP_ATOMIC. 3241da177e4SLinus Torvalds */ 3251da177e4SLinus Torvalds 32686a76cafSVictor Fusco struct sk_buff *skb_clone(struct sk_buff *skb, unsigned int __nocast gfp_mask) 3271da177e4SLinus Torvalds { 3281da177e4SLinus Torvalds struct sk_buff *n = kmem_cache_alloc(skbuff_head_cache, gfp_mask); 3291da177e4SLinus Torvalds 3301da177e4SLinus Torvalds if (!n) 3311da177e4SLinus Torvalds return NULL; 3321da177e4SLinus Torvalds 3331da177e4SLinus Torvalds #define C(x) n->x = skb->x 3341da177e4SLinus Torvalds 3351da177e4SLinus Torvalds n->next = n->prev = NULL; 3361da177e4SLinus Torvalds n->list = NULL; 3371da177e4SLinus Torvalds n->sk = NULL; 3381da177e4SLinus Torvalds C(stamp); 3391da177e4SLinus Torvalds C(dev); 3401da177e4SLinus Torvalds C(real_dev); 3411da177e4SLinus Torvalds C(h); 3421da177e4SLinus Torvalds C(nh); 3431da177e4SLinus Torvalds C(mac); 3441da177e4SLinus Torvalds C(dst); 3451da177e4SLinus Torvalds dst_clone(skb->dst); 3461da177e4SLinus Torvalds C(sp); 3471da177e4SLinus Torvalds #ifdef CONFIG_INET 3481da177e4SLinus Torvalds secpath_get(skb->sp); 3491da177e4SLinus Torvalds #endif 3501da177e4SLinus Torvalds memcpy(n->cb, skb->cb, sizeof(skb->cb)); 3511da177e4SLinus Torvalds C(len); 3521da177e4SLinus Torvalds C(data_len); 3531da177e4SLinus Torvalds C(csum); 3541da177e4SLinus Torvalds C(local_df); 3551da177e4SLinus Torvalds n->cloned = 1; 3561da177e4SLinus Torvalds n->nohdr = 0; 3571da177e4SLinus Torvalds C(pkt_type); 3581da177e4SLinus Torvalds C(ip_summed); 3591da177e4SLinus Torvalds C(priority); 3601da177e4SLinus Torvalds C(protocol); 3611da177e4SLinus Torvalds n->destructor = NULL; 3621da177e4SLinus Torvalds #ifdef CONFIG_NETFILTER 3631da177e4SLinus Torvalds C(nfmark); 3641da177e4SLinus Torvalds C(nfcache); 3651da177e4SLinus Torvalds C(nfct); 3661da177e4SLinus Torvalds nf_conntrack_get(skb->nfct); 3671da177e4SLinus Torvalds C(nfctinfo); 3681da177e4SLinus Torvalds #ifdef CONFIG_BRIDGE_NETFILTER 3691da177e4SLinus Torvalds C(nf_bridge); 3701da177e4SLinus Torvalds nf_bridge_get(skb->nf_bridge); 3711da177e4SLinus Torvalds #endif 3721da177e4SLinus Torvalds #endif /*CONFIG_NETFILTER*/ 3731da177e4SLinus Torvalds #if defined(CONFIG_HIPPI) 3741da177e4SLinus Torvalds C(private); 3751da177e4SLinus Torvalds #endif 3761da177e4SLinus Torvalds #ifdef CONFIG_NET_SCHED 3771da177e4SLinus Torvalds C(tc_index); 3781da177e4SLinus Torvalds #ifdef CONFIG_NET_CLS_ACT 3791da177e4SLinus Torvalds n->tc_verd = SET_TC_VERD(skb->tc_verd,0); 380b72f6eccSDavid S. Miller n->tc_verd = CLR_TC_OK2MUNGE(n->tc_verd); 381b72f6eccSDavid S. Miller n->tc_verd = CLR_TC_MUNGED(n->tc_verd); 3821da177e4SLinus Torvalds C(input_dev); 3831da177e4SLinus Torvalds C(tc_classid); 3841da177e4SLinus Torvalds #endif 3851da177e4SLinus Torvalds 3861da177e4SLinus Torvalds #endif 3871da177e4SLinus Torvalds C(truesize); 3881da177e4SLinus Torvalds atomic_set(&n->users, 1); 3891da177e4SLinus Torvalds C(head); 3901da177e4SLinus Torvalds C(data); 3911da177e4SLinus Torvalds C(tail); 3921da177e4SLinus Torvalds C(end); 3931da177e4SLinus Torvalds 3941da177e4SLinus Torvalds atomic_inc(&(skb_shinfo(skb)->dataref)); 3951da177e4SLinus Torvalds skb->cloned = 1; 3961da177e4SLinus Torvalds 3971da177e4SLinus Torvalds return n; 3981da177e4SLinus Torvalds } 3991da177e4SLinus Torvalds 4001da177e4SLinus Torvalds static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old) 4011da177e4SLinus Torvalds { 4021da177e4SLinus Torvalds /* 4031da177e4SLinus Torvalds * Shift between the two data areas in bytes 4041da177e4SLinus Torvalds */ 4051da177e4SLinus Torvalds unsigned long offset = new->data - old->data; 4061da177e4SLinus Torvalds 4071da177e4SLinus Torvalds new->list = NULL; 4081da177e4SLinus Torvalds new->sk = NULL; 4091da177e4SLinus Torvalds new->dev = old->dev; 4101da177e4SLinus Torvalds new->real_dev = old->real_dev; 4111da177e4SLinus Torvalds new->priority = old->priority; 4121da177e4SLinus Torvalds new->protocol = old->protocol; 4131da177e4SLinus Torvalds new->dst = dst_clone(old->dst); 4141da177e4SLinus Torvalds #ifdef CONFIG_INET 4151da177e4SLinus Torvalds new->sp = secpath_get(old->sp); 4161da177e4SLinus Torvalds #endif 4171da177e4SLinus Torvalds new->h.raw = old->h.raw + offset; 4181da177e4SLinus Torvalds new->nh.raw = old->nh.raw + offset; 4191da177e4SLinus Torvalds new->mac.raw = old->mac.raw + offset; 4201da177e4SLinus Torvalds memcpy(new->cb, old->cb, sizeof(old->cb)); 4211da177e4SLinus Torvalds new->local_df = old->local_df; 4221da177e4SLinus Torvalds new->pkt_type = old->pkt_type; 4231da177e4SLinus Torvalds new->stamp = old->stamp; 4241da177e4SLinus Torvalds new->destructor = NULL; 4251da177e4SLinus Torvalds #ifdef CONFIG_NETFILTER 4261da177e4SLinus Torvalds new->nfmark = old->nfmark; 4271da177e4SLinus Torvalds new->nfcache = old->nfcache; 4281da177e4SLinus Torvalds new->nfct = old->nfct; 4291da177e4SLinus Torvalds nf_conntrack_get(old->nfct); 4301da177e4SLinus Torvalds new->nfctinfo = old->nfctinfo; 4311da177e4SLinus Torvalds #ifdef CONFIG_BRIDGE_NETFILTER 4321da177e4SLinus Torvalds new->nf_bridge = old->nf_bridge; 4331da177e4SLinus Torvalds nf_bridge_get(old->nf_bridge); 4341da177e4SLinus Torvalds #endif 4351da177e4SLinus Torvalds #endif 4361da177e4SLinus Torvalds #ifdef CONFIG_NET_SCHED 4371da177e4SLinus Torvalds #ifdef CONFIG_NET_CLS_ACT 4381da177e4SLinus Torvalds new->tc_verd = old->tc_verd; 4391da177e4SLinus Torvalds #endif 4401da177e4SLinus Torvalds new->tc_index = old->tc_index; 4411da177e4SLinus Torvalds #endif 4421da177e4SLinus Torvalds atomic_set(&new->users, 1); 4431da177e4SLinus Torvalds skb_shinfo(new)->tso_size = skb_shinfo(old)->tso_size; 4441da177e4SLinus Torvalds skb_shinfo(new)->tso_segs = skb_shinfo(old)->tso_segs; 4451da177e4SLinus Torvalds } 4461da177e4SLinus Torvalds 4471da177e4SLinus Torvalds /** 4481da177e4SLinus Torvalds * skb_copy - create private copy of an sk_buff 4491da177e4SLinus Torvalds * @skb: buffer to copy 4501da177e4SLinus Torvalds * @gfp_mask: allocation priority 4511da177e4SLinus Torvalds * 4521da177e4SLinus Torvalds * Make a copy of both an &sk_buff and its data. This is used when the 4531da177e4SLinus Torvalds * caller wishes to modify the data and needs a private copy of the 4541da177e4SLinus Torvalds * data to alter. Returns %NULL on failure or the pointer to the buffer 4551da177e4SLinus Torvalds * on success. The returned buffer has a reference count of 1. 4561da177e4SLinus Torvalds * 4571da177e4SLinus Torvalds * As by-product this function converts non-linear &sk_buff to linear 4581da177e4SLinus Torvalds * one, so that &sk_buff becomes completely private and caller is allowed 4591da177e4SLinus Torvalds * to modify all the data of returned buffer. This means that this 4601da177e4SLinus Torvalds * function is not recommended for use in circumstances when only 4611da177e4SLinus Torvalds * header is going to be modified. Use pskb_copy() instead. 4621da177e4SLinus Torvalds */ 4631da177e4SLinus Torvalds 46486a76cafSVictor Fusco struct sk_buff *skb_copy(const struct sk_buff *skb, unsigned int __nocast gfp_mask) 4651da177e4SLinus Torvalds { 4661da177e4SLinus Torvalds int headerlen = skb->data - skb->head; 4671da177e4SLinus Torvalds /* 4681da177e4SLinus Torvalds * Allocate the copy buffer 4691da177e4SLinus Torvalds */ 4701da177e4SLinus Torvalds struct sk_buff *n = alloc_skb(skb->end - skb->head + skb->data_len, 4711da177e4SLinus Torvalds gfp_mask); 4721da177e4SLinus Torvalds if (!n) 4731da177e4SLinus Torvalds return NULL; 4741da177e4SLinus Torvalds 4751da177e4SLinus Torvalds /* Set the data pointer */ 4761da177e4SLinus Torvalds skb_reserve(n, headerlen); 4771da177e4SLinus Torvalds /* Set the tail pointer and length */ 4781da177e4SLinus Torvalds skb_put(n, skb->len); 4791da177e4SLinus Torvalds n->csum = skb->csum; 4801da177e4SLinus Torvalds n->ip_summed = skb->ip_summed; 4811da177e4SLinus Torvalds 4821da177e4SLinus Torvalds if (skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len)) 4831da177e4SLinus Torvalds BUG(); 4841da177e4SLinus Torvalds 4851da177e4SLinus Torvalds copy_skb_header(n, skb); 4861da177e4SLinus Torvalds return n; 4871da177e4SLinus Torvalds } 4881da177e4SLinus Torvalds 4891da177e4SLinus Torvalds 4901da177e4SLinus Torvalds /** 4911da177e4SLinus Torvalds * pskb_copy - create copy of an sk_buff with private head. 4921da177e4SLinus Torvalds * @skb: buffer to copy 4931da177e4SLinus Torvalds * @gfp_mask: allocation priority 4941da177e4SLinus Torvalds * 4951da177e4SLinus Torvalds * Make a copy of both an &sk_buff and part of its data, located 4961da177e4SLinus Torvalds * in header. Fragmented data remain shared. This is used when 4971da177e4SLinus Torvalds * the caller wishes to modify only header of &sk_buff and needs 4981da177e4SLinus Torvalds * private copy of the header to alter. Returns %NULL on failure 4991da177e4SLinus Torvalds * or the pointer to the buffer on success. 5001da177e4SLinus Torvalds * The returned buffer has a reference count of 1. 5011da177e4SLinus Torvalds */ 5021da177e4SLinus Torvalds 50386a76cafSVictor Fusco struct sk_buff *pskb_copy(struct sk_buff *skb, unsigned int __nocast gfp_mask) 5041da177e4SLinus Torvalds { 5051da177e4SLinus Torvalds /* 5061da177e4SLinus Torvalds * Allocate the copy buffer 5071da177e4SLinus Torvalds */ 5081da177e4SLinus Torvalds struct sk_buff *n = alloc_skb(skb->end - skb->head, gfp_mask); 5091da177e4SLinus Torvalds 5101da177e4SLinus Torvalds if (!n) 5111da177e4SLinus Torvalds goto out; 5121da177e4SLinus Torvalds 5131da177e4SLinus Torvalds /* Set the data pointer */ 5141da177e4SLinus Torvalds skb_reserve(n, skb->data - skb->head); 5151da177e4SLinus Torvalds /* Set the tail pointer and length */ 5161da177e4SLinus Torvalds skb_put(n, skb_headlen(skb)); 5171da177e4SLinus Torvalds /* Copy the bytes */ 5181da177e4SLinus Torvalds memcpy(n->data, skb->data, n->len); 5191da177e4SLinus Torvalds n->csum = skb->csum; 5201da177e4SLinus Torvalds n->ip_summed = skb->ip_summed; 5211da177e4SLinus Torvalds 5221da177e4SLinus Torvalds n->data_len = skb->data_len; 5231da177e4SLinus Torvalds n->len = skb->len; 5241da177e4SLinus Torvalds 5251da177e4SLinus Torvalds if (skb_shinfo(skb)->nr_frags) { 5261da177e4SLinus Torvalds int i; 5271da177e4SLinus Torvalds 5281da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 5291da177e4SLinus Torvalds skb_shinfo(n)->frags[i] = skb_shinfo(skb)->frags[i]; 5301da177e4SLinus Torvalds get_page(skb_shinfo(n)->frags[i].page); 5311da177e4SLinus Torvalds } 5321da177e4SLinus Torvalds skb_shinfo(n)->nr_frags = i; 5331da177e4SLinus Torvalds } 5341da177e4SLinus Torvalds 5351da177e4SLinus Torvalds if (skb_shinfo(skb)->frag_list) { 5361da177e4SLinus Torvalds skb_shinfo(n)->frag_list = skb_shinfo(skb)->frag_list; 5371da177e4SLinus Torvalds skb_clone_fraglist(n); 5381da177e4SLinus Torvalds } 5391da177e4SLinus Torvalds 5401da177e4SLinus Torvalds copy_skb_header(n, skb); 5411da177e4SLinus Torvalds out: 5421da177e4SLinus Torvalds return n; 5431da177e4SLinus Torvalds } 5441da177e4SLinus Torvalds 5451da177e4SLinus Torvalds /** 5461da177e4SLinus Torvalds * pskb_expand_head - reallocate header of &sk_buff 5471da177e4SLinus Torvalds * @skb: buffer to reallocate 5481da177e4SLinus Torvalds * @nhead: room to add at head 5491da177e4SLinus Torvalds * @ntail: room to add at tail 5501da177e4SLinus Torvalds * @gfp_mask: allocation priority 5511da177e4SLinus Torvalds * 5521da177e4SLinus Torvalds * Expands (or creates identical copy, if &nhead and &ntail are zero) 5531da177e4SLinus Torvalds * header of skb. &sk_buff itself is not changed. &sk_buff MUST have 5541da177e4SLinus Torvalds * reference count of 1. Returns zero in the case of success or error, 5551da177e4SLinus Torvalds * if expansion failed. In the last case, &sk_buff is not changed. 5561da177e4SLinus Torvalds * 5571da177e4SLinus Torvalds * All the pointers pointing into skb header may change and must be 5581da177e4SLinus Torvalds * reloaded after call to this function. 5591da177e4SLinus Torvalds */ 5601da177e4SLinus Torvalds 56186a76cafSVictor Fusco int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, 56286a76cafSVictor Fusco unsigned int __nocast gfp_mask) 5631da177e4SLinus Torvalds { 5641da177e4SLinus Torvalds int i; 5651da177e4SLinus Torvalds u8 *data; 5661da177e4SLinus Torvalds int size = nhead + (skb->end - skb->head) + ntail; 5671da177e4SLinus Torvalds long off; 5681da177e4SLinus Torvalds 5691da177e4SLinus Torvalds if (skb_shared(skb)) 5701da177e4SLinus Torvalds BUG(); 5711da177e4SLinus Torvalds 5721da177e4SLinus Torvalds size = SKB_DATA_ALIGN(size); 5731da177e4SLinus Torvalds 5741da177e4SLinus Torvalds data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask); 5751da177e4SLinus Torvalds if (!data) 5761da177e4SLinus Torvalds goto nodata; 5771da177e4SLinus Torvalds 5781da177e4SLinus Torvalds /* Copy only real data... and, alas, header. This should be 5791da177e4SLinus Torvalds * optimized for the cases when header is void. */ 5801da177e4SLinus Torvalds memcpy(data + nhead, skb->head, skb->tail - skb->head); 5811da177e4SLinus Torvalds memcpy(data + size, skb->end, sizeof(struct skb_shared_info)); 5821da177e4SLinus Torvalds 5831da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) 5841da177e4SLinus Torvalds get_page(skb_shinfo(skb)->frags[i].page); 5851da177e4SLinus Torvalds 5861da177e4SLinus Torvalds if (skb_shinfo(skb)->frag_list) 5871da177e4SLinus Torvalds skb_clone_fraglist(skb); 5881da177e4SLinus Torvalds 5891da177e4SLinus Torvalds skb_release_data(skb); 5901da177e4SLinus Torvalds 5911da177e4SLinus Torvalds off = (data + nhead) - skb->head; 5921da177e4SLinus Torvalds 5931da177e4SLinus Torvalds skb->head = data; 5941da177e4SLinus Torvalds skb->end = data + size; 5951da177e4SLinus Torvalds skb->data += off; 5961da177e4SLinus Torvalds skb->tail += off; 5971da177e4SLinus Torvalds skb->mac.raw += off; 5981da177e4SLinus Torvalds skb->h.raw += off; 5991da177e4SLinus Torvalds skb->nh.raw += off; 6001da177e4SLinus Torvalds skb->cloned = 0; 6011da177e4SLinus Torvalds skb->nohdr = 0; 6021da177e4SLinus Torvalds atomic_set(&skb_shinfo(skb)->dataref, 1); 6031da177e4SLinus Torvalds return 0; 6041da177e4SLinus Torvalds 6051da177e4SLinus Torvalds nodata: 6061da177e4SLinus Torvalds return -ENOMEM; 6071da177e4SLinus Torvalds } 6081da177e4SLinus Torvalds 6091da177e4SLinus Torvalds /* Make private copy of skb with writable head and some headroom */ 6101da177e4SLinus Torvalds 6111da177e4SLinus Torvalds struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, unsigned int headroom) 6121da177e4SLinus Torvalds { 6131da177e4SLinus Torvalds struct sk_buff *skb2; 6141da177e4SLinus Torvalds int delta = headroom - skb_headroom(skb); 6151da177e4SLinus Torvalds 6161da177e4SLinus Torvalds if (delta <= 0) 6171da177e4SLinus Torvalds skb2 = pskb_copy(skb, GFP_ATOMIC); 6181da177e4SLinus Torvalds else { 6191da177e4SLinus Torvalds skb2 = skb_clone(skb, GFP_ATOMIC); 6201da177e4SLinus Torvalds if (skb2 && pskb_expand_head(skb2, SKB_DATA_ALIGN(delta), 0, 6211da177e4SLinus Torvalds GFP_ATOMIC)) { 6221da177e4SLinus Torvalds kfree_skb(skb2); 6231da177e4SLinus Torvalds skb2 = NULL; 6241da177e4SLinus Torvalds } 6251da177e4SLinus Torvalds } 6261da177e4SLinus Torvalds return skb2; 6271da177e4SLinus Torvalds } 6281da177e4SLinus Torvalds 6291da177e4SLinus Torvalds 6301da177e4SLinus Torvalds /** 6311da177e4SLinus Torvalds * skb_copy_expand - copy and expand sk_buff 6321da177e4SLinus Torvalds * @skb: buffer to copy 6331da177e4SLinus Torvalds * @newheadroom: new free bytes at head 6341da177e4SLinus Torvalds * @newtailroom: new free bytes at tail 6351da177e4SLinus Torvalds * @gfp_mask: allocation priority 6361da177e4SLinus Torvalds * 6371da177e4SLinus Torvalds * Make a copy of both an &sk_buff and its data and while doing so 6381da177e4SLinus Torvalds * allocate additional space. 6391da177e4SLinus Torvalds * 6401da177e4SLinus Torvalds * This is used when the caller wishes to modify the data and needs a 6411da177e4SLinus Torvalds * private copy of the data to alter as well as more space for new fields. 6421da177e4SLinus Torvalds * Returns %NULL on failure or the pointer to the buffer 6431da177e4SLinus Torvalds * on success. The returned buffer has a reference count of 1. 6441da177e4SLinus Torvalds * 6451da177e4SLinus Torvalds * You must pass %GFP_ATOMIC as the allocation priority if this function 6461da177e4SLinus Torvalds * is called from an interrupt. 6471da177e4SLinus Torvalds * 6481da177e4SLinus Torvalds * BUG ALERT: ip_summed is not copied. Why does this work? Is it used 6491da177e4SLinus Torvalds * only by netfilter in the cases when checksum is recalculated? --ANK 6501da177e4SLinus Torvalds */ 6511da177e4SLinus Torvalds struct sk_buff *skb_copy_expand(const struct sk_buff *skb, 65286a76cafSVictor Fusco int newheadroom, int newtailroom, 65386a76cafSVictor Fusco unsigned int __nocast gfp_mask) 6541da177e4SLinus Torvalds { 6551da177e4SLinus Torvalds /* 6561da177e4SLinus Torvalds * Allocate the copy buffer 6571da177e4SLinus Torvalds */ 6581da177e4SLinus Torvalds struct sk_buff *n = alloc_skb(newheadroom + skb->len + newtailroom, 6591da177e4SLinus Torvalds gfp_mask); 6601da177e4SLinus Torvalds int head_copy_len, head_copy_off; 6611da177e4SLinus Torvalds 6621da177e4SLinus Torvalds if (!n) 6631da177e4SLinus Torvalds return NULL; 6641da177e4SLinus Torvalds 6651da177e4SLinus Torvalds skb_reserve(n, newheadroom); 6661da177e4SLinus Torvalds 6671da177e4SLinus Torvalds /* Set the tail pointer and length */ 6681da177e4SLinus Torvalds skb_put(n, skb->len); 6691da177e4SLinus Torvalds 6701da177e4SLinus Torvalds head_copy_len = skb_headroom(skb); 6711da177e4SLinus Torvalds head_copy_off = 0; 6721da177e4SLinus Torvalds if (newheadroom <= head_copy_len) 6731da177e4SLinus Torvalds head_copy_len = newheadroom; 6741da177e4SLinus Torvalds else 6751da177e4SLinus Torvalds head_copy_off = newheadroom - head_copy_len; 6761da177e4SLinus Torvalds 6771da177e4SLinus Torvalds /* Copy the linear header and data. */ 6781da177e4SLinus Torvalds if (skb_copy_bits(skb, -head_copy_len, n->head + head_copy_off, 6791da177e4SLinus Torvalds skb->len + head_copy_len)) 6801da177e4SLinus Torvalds BUG(); 6811da177e4SLinus Torvalds 6821da177e4SLinus Torvalds copy_skb_header(n, skb); 6831da177e4SLinus Torvalds 6841da177e4SLinus Torvalds return n; 6851da177e4SLinus Torvalds } 6861da177e4SLinus Torvalds 6871da177e4SLinus Torvalds /** 6881da177e4SLinus Torvalds * skb_pad - zero pad the tail of an skb 6891da177e4SLinus Torvalds * @skb: buffer to pad 6901da177e4SLinus Torvalds * @pad: space to pad 6911da177e4SLinus Torvalds * 6921da177e4SLinus Torvalds * Ensure that a buffer is followed by a padding area that is zero 6931da177e4SLinus Torvalds * filled. Used by network drivers which may DMA or transfer data 6941da177e4SLinus Torvalds * beyond the buffer end onto the wire. 6951da177e4SLinus Torvalds * 6961da177e4SLinus Torvalds * May return NULL in out of memory cases. 6971da177e4SLinus Torvalds */ 6981da177e4SLinus Torvalds 6991da177e4SLinus Torvalds struct sk_buff *skb_pad(struct sk_buff *skb, int pad) 7001da177e4SLinus Torvalds { 7011da177e4SLinus Torvalds struct sk_buff *nskb; 7021da177e4SLinus Torvalds 7031da177e4SLinus Torvalds /* If the skbuff is non linear tailroom is always zero.. */ 7041da177e4SLinus Torvalds if (skb_tailroom(skb) >= pad) { 7051da177e4SLinus Torvalds memset(skb->data+skb->len, 0, pad); 7061da177e4SLinus Torvalds return skb; 7071da177e4SLinus Torvalds } 7081da177e4SLinus Torvalds 7091da177e4SLinus Torvalds nskb = skb_copy_expand(skb, skb_headroom(skb), skb_tailroom(skb) + pad, GFP_ATOMIC); 7101da177e4SLinus Torvalds kfree_skb(skb); 7111da177e4SLinus Torvalds if (nskb) 7121da177e4SLinus Torvalds memset(nskb->data+nskb->len, 0, pad); 7131da177e4SLinus Torvalds return nskb; 7141da177e4SLinus Torvalds } 7151da177e4SLinus Torvalds 7161da177e4SLinus Torvalds /* Trims skb to length len. It can change skb pointers, if "realloc" is 1. 7171da177e4SLinus Torvalds * If realloc==0 and trimming is impossible without change of data, 7181da177e4SLinus Torvalds * it is BUG(). 7191da177e4SLinus Torvalds */ 7201da177e4SLinus Torvalds 7211da177e4SLinus Torvalds int ___pskb_trim(struct sk_buff *skb, unsigned int len, int realloc) 7221da177e4SLinus Torvalds { 7231da177e4SLinus Torvalds int offset = skb_headlen(skb); 7241da177e4SLinus Torvalds int nfrags = skb_shinfo(skb)->nr_frags; 7251da177e4SLinus Torvalds int i; 7261da177e4SLinus Torvalds 7271da177e4SLinus Torvalds for (i = 0; i < nfrags; i++) { 7281da177e4SLinus Torvalds int end = offset + skb_shinfo(skb)->frags[i].size; 7291da177e4SLinus Torvalds if (end > len) { 7301da177e4SLinus Torvalds if (skb_cloned(skb)) { 7311da177e4SLinus Torvalds if (!realloc) 7321da177e4SLinus Torvalds BUG(); 7331da177e4SLinus Torvalds if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 7341da177e4SLinus Torvalds return -ENOMEM; 7351da177e4SLinus Torvalds } 7361da177e4SLinus Torvalds if (len <= offset) { 7371da177e4SLinus Torvalds put_page(skb_shinfo(skb)->frags[i].page); 7381da177e4SLinus Torvalds skb_shinfo(skb)->nr_frags--; 7391da177e4SLinus Torvalds } else { 7401da177e4SLinus Torvalds skb_shinfo(skb)->frags[i].size = len - offset; 7411da177e4SLinus Torvalds } 7421da177e4SLinus Torvalds } 7431da177e4SLinus Torvalds offset = end; 7441da177e4SLinus Torvalds } 7451da177e4SLinus Torvalds 7461da177e4SLinus Torvalds if (offset < len) { 7471da177e4SLinus Torvalds skb->data_len -= skb->len - len; 7481da177e4SLinus Torvalds skb->len = len; 7491da177e4SLinus Torvalds } else { 7501da177e4SLinus Torvalds if (len <= skb_headlen(skb)) { 7511da177e4SLinus Torvalds skb->len = len; 7521da177e4SLinus Torvalds skb->data_len = 0; 7531da177e4SLinus Torvalds skb->tail = skb->data + len; 7541da177e4SLinus Torvalds if (skb_shinfo(skb)->frag_list && !skb_cloned(skb)) 7551da177e4SLinus Torvalds skb_drop_fraglist(skb); 7561da177e4SLinus Torvalds } else { 7571da177e4SLinus Torvalds skb->data_len -= skb->len - len; 7581da177e4SLinus Torvalds skb->len = len; 7591da177e4SLinus Torvalds } 7601da177e4SLinus Torvalds } 7611da177e4SLinus Torvalds 7621da177e4SLinus Torvalds return 0; 7631da177e4SLinus Torvalds } 7641da177e4SLinus Torvalds 7651da177e4SLinus Torvalds /** 7661da177e4SLinus Torvalds * __pskb_pull_tail - advance tail of skb header 7671da177e4SLinus Torvalds * @skb: buffer to reallocate 7681da177e4SLinus Torvalds * @delta: number of bytes to advance tail 7691da177e4SLinus Torvalds * 7701da177e4SLinus Torvalds * The function makes a sense only on a fragmented &sk_buff, 7711da177e4SLinus Torvalds * it expands header moving its tail forward and copying necessary 7721da177e4SLinus Torvalds * data from fragmented part. 7731da177e4SLinus Torvalds * 7741da177e4SLinus Torvalds * &sk_buff MUST have reference count of 1. 7751da177e4SLinus Torvalds * 7761da177e4SLinus Torvalds * Returns %NULL (and &sk_buff does not change) if pull failed 7771da177e4SLinus Torvalds * or value of new tail of skb in the case of success. 7781da177e4SLinus Torvalds * 7791da177e4SLinus Torvalds * All the pointers pointing into skb header may change and must be 7801da177e4SLinus Torvalds * reloaded after call to this function. 7811da177e4SLinus Torvalds */ 7821da177e4SLinus Torvalds 7831da177e4SLinus Torvalds /* Moves tail of skb head forward, copying data from fragmented part, 7841da177e4SLinus Torvalds * when it is necessary. 7851da177e4SLinus Torvalds * 1. It may fail due to malloc failure. 7861da177e4SLinus Torvalds * 2. It may change skb pointers. 7871da177e4SLinus Torvalds * 7881da177e4SLinus Torvalds * It is pretty complicated. Luckily, it is called only in exceptional cases. 7891da177e4SLinus Torvalds */ 7901da177e4SLinus Torvalds unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta) 7911da177e4SLinus Torvalds { 7921da177e4SLinus Torvalds /* If skb has not enough free space at tail, get new one 7931da177e4SLinus Torvalds * plus 128 bytes for future expansions. If we have enough 7941da177e4SLinus Torvalds * room at tail, reallocate without expansion only if skb is cloned. 7951da177e4SLinus Torvalds */ 7961da177e4SLinus Torvalds int i, k, eat = (skb->tail + delta) - skb->end; 7971da177e4SLinus Torvalds 7981da177e4SLinus Torvalds if (eat > 0 || skb_cloned(skb)) { 7991da177e4SLinus Torvalds if (pskb_expand_head(skb, 0, eat > 0 ? eat + 128 : 0, 8001da177e4SLinus Torvalds GFP_ATOMIC)) 8011da177e4SLinus Torvalds return NULL; 8021da177e4SLinus Torvalds } 8031da177e4SLinus Torvalds 8041da177e4SLinus Torvalds if (skb_copy_bits(skb, skb_headlen(skb), skb->tail, delta)) 8051da177e4SLinus Torvalds BUG(); 8061da177e4SLinus Torvalds 8071da177e4SLinus Torvalds /* Optimization: no fragments, no reasons to preestimate 8081da177e4SLinus Torvalds * size of pulled pages. Superb. 8091da177e4SLinus Torvalds */ 8101da177e4SLinus Torvalds if (!skb_shinfo(skb)->frag_list) 8111da177e4SLinus Torvalds goto pull_pages; 8121da177e4SLinus Torvalds 8131da177e4SLinus Torvalds /* Estimate size of pulled pages. */ 8141da177e4SLinus Torvalds eat = delta; 8151da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 8161da177e4SLinus Torvalds if (skb_shinfo(skb)->frags[i].size >= eat) 8171da177e4SLinus Torvalds goto pull_pages; 8181da177e4SLinus Torvalds eat -= skb_shinfo(skb)->frags[i].size; 8191da177e4SLinus Torvalds } 8201da177e4SLinus Torvalds 8211da177e4SLinus Torvalds /* If we need update frag list, we are in troubles. 8221da177e4SLinus Torvalds * Certainly, it possible to add an offset to skb data, 8231da177e4SLinus Torvalds * but taking into account that pulling is expected to 8241da177e4SLinus Torvalds * be very rare operation, it is worth to fight against 8251da177e4SLinus Torvalds * further bloating skb head and crucify ourselves here instead. 8261da177e4SLinus Torvalds * Pure masohism, indeed. 8)8) 8271da177e4SLinus Torvalds */ 8281da177e4SLinus Torvalds if (eat) { 8291da177e4SLinus Torvalds struct sk_buff *list = skb_shinfo(skb)->frag_list; 8301da177e4SLinus Torvalds struct sk_buff *clone = NULL; 8311da177e4SLinus Torvalds struct sk_buff *insp = NULL; 8321da177e4SLinus Torvalds 8331da177e4SLinus Torvalds do { 8341da177e4SLinus Torvalds if (!list) 8351da177e4SLinus Torvalds BUG(); 8361da177e4SLinus Torvalds 8371da177e4SLinus Torvalds if (list->len <= eat) { 8381da177e4SLinus Torvalds /* Eaten as whole. */ 8391da177e4SLinus Torvalds eat -= list->len; 8401da177e4SLinus Torvalds list = list->next; 8411da177e4SLinus Torvalds insp = list; 8421da177e4SLinus Torvalds } else { 8431da177e4SLinus Torvalds /* Eaten partially. */ 8441da177e4SLinus Torvalds 8451da177e4SLinus Torvalds if (skb_shared(list)) { 8461da177e4SLinus Torvalds /* Sucks! We need to fork list. :-( */ 8471da177e4SLinus Torvalds clone = skb_clone(list, GFP_ATOMIC); 8481da177e4SLinus Torvalds if (!clone) 8491da177e4SLinus Torvalds return NULL; 8501da177e4SLinus Torvalds insp = list->next; 8511da177e4SLinus Torvalds list = clone; 8521da177e4SLinus Torvalds } else { 8531da177e4SLinus Torvalds /* This may be pulled without 8541da177e4SLinus Torvalds * problems. */ 8551da177e4SLinus Torvalds insp = list; 8561da177e4SLinus Torvalds } 8571da177e4SLinus Torvalds if (!pskb_pull(list, eat)) { 8581da177e4SLinus Torvalds if (clone) 8591da177e4SLinus Torvalds kfree_skb(clone); 8601da177e4SLinus Torvalds return NULL; 8611da177e4SLinus Torvalds } 8621da177e4SLinus Torvalds break; 8631da177e4SLinus Torvalds } 8641da177e4SLinus Torvalds } while (eat); 8651da177e4SLinus Torvalds 8661da177e4SLinus Torvalds /* Free pulled out fragments. */ 8671da177e4SLinus Torvalds while ((list = skb_shinfo(skb)->frag_list) != insp) { 8681da177e4SLinus Torvalds skb_shinfo(skb)->frag_list = list->next; 8691da177e4SLinus Torvalds kfree_skb(list); 8701da177e4SLinus Torvalds } 8711da177e4SLinus Torvalds /* And insert new clone at head. */ 8721da177e4SLinus Torvalds if (clone) { 8731da177e4SLinus Torvalds clone->next = list; 8741da177e4SLinus Torvalds skb_shinfo(skb)->frag_list = clone; 8751da177e4SLinus Torvalds } 8761da177e4SLinus Torvalds } 8771da177e4SLinus Torvalds /* Success! Now we may commit changes to skb data. */ 8781da177e4SLinus Torvalds 8791da177e4SLinus Torvalds pull_pages: 8801da177e4SLinus Torvalds eat = delta; 8811da177e4SLinus Torvalds k = 0; 8821da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 8831da177e4SLinus Torvalds if (skb_shinfo(skb)->frags[i].size <= eat) { 8841da177e4SLinus Torvalds put_page(skb_shinfo(skb)->frags[i].page); 8851da177e4SLinus Torvalds eat -= skb_shinfo(skb)->frags[i].size; 8861da177e4SLinus Torvalds } else { 8871da177e4SLinus Torvalds skb_shinfo(skb)->frags[k] = skb_shinfo(skb)->frags[i]; 8881da177e4SLinus Torvalds if (eat) { 8891da177e4SLinus Torvalds skb_shinfo(skb)->frags[k].page_offset += eat; 8901da177e4SLinus Torvalds skb_shinfo(skb)->frags[k].size -= eat; 8911da177e4SLinus Torvalds eat = 0; 8921da177e4SLinus Torvalds } 8931da177e4SLinus Torvalds k++; 8941da177e4SLinus Torvalds } 8951da177e4SLinus Torvalds } 8961da177e4SLinus Torvalds skb_shinfo(skb)->nr_frags = k; 8971da177e4SLinus Torvalds 8981da177e4SLinus Torvalds skb->tail += delta; 8991da177e4SLinus Torvalds skb->data_len -= delta; 9001da177e4SLinus Torvalds 9011da177e4SLinus Torvalds return skb->tail; 9021da177e4SLinus Torvalds } 9031da177e4SLinus Torvalds 9041da177e4SLinus Torvalds /* Copy some data bits from skb to kernel buffer. */ 9051da177e4SLinus Torvalds 9061da177e4SLinus Torvalds int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len) 9071da177e4SLinus Torvalds { 9081da177e4SLinus Torvalds int i, copy; 9091da177e4SLinus Torvalds int start = skb_headlen(skb); 9101da177e4SLinus Torvalds 9111da177e4SLinus Torvalds if (offset > (int)skb->len - len) 9121da177e4SLinus Torvalds goto fault; 9131da177e4SLinus Torvalds 9141da177e4SLinus Torvalds /* Copy header. */ 9151da177e4SLinus Torvalds if ((copy = start - offset) > 0) { 9161da177e4SLinus Torvalds if (copy > len) 9171da177e4SLinus Torvalds copy = len; 9181da177e4SLinus Torvalds memcpy(to, skb->data + offset, copy); 9191da177e4SLinus Torvalds if ((len -= copy) == 0) 9201da177e4SLinus Torvalds return 0; 9211da177e4SLinus Torvalds offset += copy; 9221da177e4SLinus Torvalds to += copy; 9231da177e4SLinus Torvalds } 9241da177e4SLinus Torvalds 9251da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 9261da177e4SLinus Torvalds int end; 9271da177e4SLinus Torvalds 9281da177e4SLinus Torvalds BUG_TRAP(start <= offset + len); 9291da177e4SLinus Torvalds 9301da177e4SLinus Torvalds end = start + skb_shinfo(skb)->frags[i].size; 9311da177e4SLinus Torvalds if ((copy = end - offset) > 0) { 9321da177e4SLinus Torvalds u8 *vaddr; 9331da177e4SLinus Torvalds 9341da177e4SLinus Torvalds if (copy > len) 9351da177e4SLinus Torvalds copy = len; 9361da177e4SLinus Torvalds 9371da177e4SLinus Torvalds vaddr = kmap_skb_frag(&skb_shinfo(skb)->frags[i]); 9381da177e4SLinus Torvalds memcpy(to, 9391da177e4SLinus Torvalds vaddr + skb_shinfo(skb)->frags[i].page_offset+ 9401da177e4SLinus Torvalds offset - start, copy); 9411da177e4SLinus Torvalds kunmap_skb_frag(vaddr); 9421da177e4SLinus Torvalds 9431da177e4SLinus Torvalds if ((len -= copy) == 0) 9441da177e4SLinus Torvalds return 0; 9451da177e4SLinus Torvalds offset += copy; 9461da177e4SLinus Torvalds to += copy; 9471da177e4SLinus Torvalds } 9481da177e4SLinus Torvalds start = end; 9491da177e4SLinus Torvalds } 9501da177e4SLinus Torvalds 9511da177e4SLinus Torvalds if (skb_shinfo(skb)->frag_list) { 9521da177e4SLinus Torvalds struct sk_buff *list = skb_shinfo(skb)->frag_list; 9531da177e4SLinus Torvalds 9541da177e4SLinus Torvalds for (; list; list = list->next) { 9551da177e4SLinus Torvalds int end; 9561da177e4SLinus Torvalds 9571da177e4SLinus Torvalds BUG_TRAP(start <= offset + len); 9581da177e4SLinus Torvalds 9591da177e4SLinus Torvalds end = start + list->len; 9601da177e4SLinus Torvalds if ((copy = end - offset) > 0) { 9611da177e4SLinus Torvalds if (copy > len) 9621da177e4SLinus Torvalds copy = len; 9631da177e4SLinus Torvalds if (skb_copy_bits(list, offset - start, 9641da177e4SLinus Torvalds to, copy)) 9651da177e4SLinus Torvalds goto fault; 9661da177e4SLinus Torvalds if ((len -= copy) == 0) 9671da177e4SLinus Torvalds return 0; 9681da177e4SLinus Torvalds offset += copy; 9691da177e4SLinus Torvalds to += copy; 9701da177e4SLinus Torvalds } 9711da177e4SLinus Torvalds start = end; 9721da177e4SLinus Torvalds } 9731da177e4SLinus Torvalds } 9741da177e4SLinus Torvalds if (!len) 9751da177e4SLinus Torvalds return 0; 9761da177e4SLinus Torvalds 9771da177e4SLinus Torvalds fault: 9781da177e4SLinus Torvalds return -EFAULT; 9791da177e4SLinus Torvalds } 9801da177e4SLinus Torvalds 981357b40a1SHerbert Xu /** 982357b40a1SHerbert Xu * skb_store_bits - store bits from kernel buffer to skb 983357b40a1SHerbert Xu * @skb: destination buffer 984357b40a1SHerbert Xu * @offset: offset in destination 985357b40a1SHerbert Xu * @from: source buffer 986357b40a1SHerbert Xu * @len: number of bytes to copy 987357b40a1SHerbert Xu * 988357b40a1SHerbert Xu * Copy the specified number of bytes from the source buffer to the 989357b40a1SHerbert Xu * destination skb. This function handles all the messy bits of 990357b40a1SHerbert Xu * traversing fragment lists and such. 991357b40a1SHerbert Xu */ 992357b40a1SHerbert Xu 993357b40a1SHerbert Xu int skb_store_bits(const struct sk_buff *skb, int offset, void *from, int len) 994357b40a1SHerbert Xu { 995357b40a1SHerbert Xu int i, copy; 996357b40a1SHerbert Xu int start = skb_headlen(skb); 997357b40a1SHerbert Xu 998357b40a1SHerbert Xu if (offset > (int)skb->len - len) 999357b40a1SHerbert Xu goto fault; 1000357b40a1SHerbert Xu 1001357b40a1SHerbert Xu if ((copy = start - offset) > 0) { 1002357b40a1SHerbert Xu if (copy > len) 1003357b40a1SHerbert Xu copy = len; 1004357b40a1SHerbert Xu memcpy(skb->data + offset, from, copy); 1005357b40a1SHerbert Xu if ((len -= copy) == 0) 1006357b40a1SHerbert Xu return 0; 1007357b40a1SHerbert Xu offset += copy; 1008357b40a1SHerbert Xu from += copy; 1009357b40a1SHerbert Xu } 1010357b40a1SHerbert Xu 1011357b40a1SHerbert Xu for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 1012357b40a1SHerbert Xu skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 1013357b40a1SHerbert Xu int end; 1014357b40a1SHerbert Xu 1015357b40a1SHerbert Xu BUG_TRAP(start <= offset + len); 1016357b40a1SHerbert Xu 1017357b40a1SHerbert Xu end = start + frag->size; 1018357b40a1SHerbert Xu if ((copy = end - offset) > 0) { 1019357b40a1SHerbert Xu u8 *vaddr; 1020357b40a1SHerbert Xu 1021357b40a1SHerbert Xu if (copy > len) 1022357b40a1SHerbert Xu copy = len; 1023357b40a1SHerbert Xu 1024357b40a1SHerbert Xu vaddr = kmap_skb_frag(frag); 1025357b40a1SHerbert Xu memcpy(vaddr + frag->page_offset + offset - start, 1026357b40a1SHerbert Xu from, copy); 1027357b40a1SHerbert Xu kunmap_skb_frag(vaddr); 1028357b40a1SHerbert Xu 1029357b40a1SHerbert Xu if ((len -= copy) == 0) 1030357b40a1SHerbert Xu return 0; 1031357b40a1SHerbert Xu offset += copy; 1032357b40a1SHerbert Xu from += copy; 1033357b40a1SHerbert Xu } 1034357b40a1SHerbert Xu start = end; 1035357b40a1SHerbert Xu } 1036357b40a1SHerbert Xu 1037357b40a1SHerbert Xu if (skb_shinfo(skb)->frag_list) { 1038357b40a1SHerbert Xu struct sk_buff *list = skb_shinfo(skb)->frag_list; 1039357b40a1SHerbert Xu 1040357b40a1SHerbert Xu for (; list; list = list->next) { 1041357b40a1SHerbert Xu int end; 1042357b40a1SHerbert Xu 1043357b40a1SHerbert Xu BUG_TRAP(start <= offset + len); 1044357b40a1SHerbert Xu 1045357b40a1SHerbert Xu end = start + list->len; 1046357b40a1SHerbert Xu if ((copy = end - offset) > 0) { 1047357b40a1SHerbert Xu if (copy > len) 1048357b40a1SHerbert Xu copy = len; 1049357b40a1SHerbert Xu if (skb_store_bits(list, offset - start, 1050357b40a1SHerbert Xu from, copy)) 1051357b40a1SHerbert Xu goto fault; 1052357b40a1SHerbert Xu if ((len -= copy) == 0) 1053357b40a1SHerbert Xu return 0; 1054357b40a1SHerbert Xu offset += copy; 1055357b40a1SHerbert Xu from += copy; 1056357b40a1SHerbert Xu } 1057357b40a1SHerbert Xu start = end; 1058357b40a1SHerbert Xu } 1059357b40a1SHerbert Xu } 1060357b40a1SHerbert Xu if (!len) 1061357b40a1SHerbert Xu return 0; 1062357b40a1SHerbert Xu 1063357b40a1SHerbert Xu fault: 1064357b40a1SHerbert Xu return -EFAULT; 1065357b40a1SHerbert Xu } 1066357b40a1SHerbert Xu 1067357b40a1SHerbert Xu EXPORT_SYMBOL(skb_store_bits); 1068357b40a1SHerbert Xu 10691da177e4SLinus Torvalds /* Checksum skb data. */ 10701da177e4SLinus Torvalds 10711da177e4SLinus Torvalds unsigned int skb_checksum(const struct sk_buff *skb, int offset, 10721da177e4SLinus Torvalds int len, unsigned int csum) 10731da177e4SLinus Torvalds { 10741da177e4SLinus Torvalds int start = skb_headlen(skb); 10751da177e4SLinus Torvalds int i, copy = start - offset; 10761da177e4SLinus Torvalds int pos = 0; 10771da177e4SLinus Torvalds 10781da177e4SLinus Torvalds /* Checksum header. */ 10791da177e4SLinus Torvalds if (copy > 0) { 10801da177e4SLinus Torvalds if (copy > len) 10811da177e4SLinus Torvalds copy = len; 10821da177e4SLinus Torvalds csum = csum_partial(skb->data + offset, copy, csum); 10831da177e4SLinus Torvalds if ((len -= copy) == 0) 10841da177e4SLinus Torvalds return csum; 10851da177e4SLinus Torvalds offset += copy; 10861da177e4SLinus Torvalds pos = copy; 10871da177e4SLinus Torvalds } 10881da177e4SLinus Torvalds 10891da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 10901da177e4SLinus Torvalds int end; 10911da177e4SLinus Torvalds 10921da177e4SLinus Torvalds BUG_TRAP(start <= offset + len); 10931da177e4SLinus Torvalds 10941da177e4SLinus Torvalds end = start + skb_shinfo(skb)->frags[i].size; 10951da177e4SLinus Torvalds if ((copy = end - offset) > 0) { 10961da177e4SLinus Torvalds unsigned int csum2; 10971da177e4SLinus Torvalds u8 *vaddr; 10981da177e4SLinus Torvalds skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 10991da177e4SLinus Torvalds 11001da177e4SLinus Torvalds if (copy > len) 11011da177e4SLinus Torvalds copy = len; 11021da177e4SLinus Torvalds vaddr = kmap_skb_frag(frag); 11031da177e4SLinus Torvalds csum2 = csum_partial(vaddr + frag->page_offset + 11041da177e4SLinus Torvalds offset - start, copy, 0); 11051da177e4SLinus Torvalds kunmap_skb_frag(vaddr); 11061da177e4SLinus Torvalds csum = csum_block_add(csum, csum2, pos); 11071da177e4SLinus Torvalds if (!(len -= copy)) 11081da177e4SLinus Torvalds return csum; 11091da177e4SLinus Torvalds offset += copy; 11101da177e4SLinus Torvalds pos += copy; 11111da177e4SLinus Torvalds } 11121da177e4SLinus Torvalds start = end; 11131da177e4SLinus Torvalds } 11141da177e4SLinus Torvalds 11151da177e4SLinus Torvalds if (skb_shinfo(skb)->frag_list) { 11161da177e4SLinus Torvalds struct sk_buff *list = skb_shinfo(skb)->frag_list; 11171da177e4SLinus Torvalds 11181da177e4SLinus Torvalds for (; list; list = list->next) { 11191da177e4SLinus Torvalds int end; 11201da177e4SLinus Torvalds 11211da177e4SLinus Torvalds BUG_TRAP(start <= offset + len); 11221da177e4SLinus Torvalds 11231da177e4SLinus Torvalds end = start + list->len; 11241da177e4SLinus Torvalds if ((copy = end - offset) > 0) { 11251da177e4SLinus Torvalds unsigned int csum2; 11261da177e4SLinus Torvalds if (copy > len) 11271da177e4SLinus Torvalds copy = len; 11281da177e4SLinus Torvalds csum2 = skb_checksum(list, offset - start, 11291da177e4SLinus Torvalds copy, 0); 11301da177e4SLinus Torvalds csum = csum_block_add(csum, csum2, pos); 11311da177e4SLinus Torvalds if ((len -= copy) == 0) 11321da177e4SLinus Torvalds return csum; 11331da177e4SLinus Torvalds offset += copy; 11341da177e4SLinus Torvalds pos += copy; 11351da177e4SLinus Torvalds } 11361da177e4SLinus Torvalds start = end; 11371da177e4SLinus Torvalds } 11381da177e4SLinus Torvalds } 11391da177e4SLinus Torvalds if (len) 11401da177e4SLinus Torvalds BUG(); 11411da177e4SLinus Torvalds 11421da177e4SLinus Torvalds return csum; 11431da177e4SLinus Torvalds } 11441da177e4SLinus Torvalds 11451da177e4SLinus Torvalds /* Both of above in one bottle. */ 11461da177e4SLinus Torvalds 11471da177e4SLinus Torvalds unsigned int skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, 11481da177e4SLinus Torvalds u8 *to, int len, unsigned int csum) 11491da177e4SLinus Torvalds { 11501da177e4SLinus Torvalds int start = skb_headlen(skb); 11511da177e4SLinus Torvalds int i, copy = start - offset; 11521da177e4SLinus Torvalds int pos = 0; 11531da177e4SLinus Torvalds 11541da177e4SLinus Torvalds /* Copy header. */ 11551da177e4SLinus Torvalds if (copy > 0) { 11561da177e4SLinus Torvalds if (copy > len) 11571da177e4SLinus Torvalds copy = len; 11581da177e4SLinus Torvalds csum = csum_partial_copy_nocheck(skb->data + offset, to, 11591da177e4SLinus Torvalds copy, csum); 11601da177e4SLinus Torvalds if ((len -= copy) == 0) 11611da177e4SLinus Torvalds return csum; 11621da177e4SLinus Torvalds offset += copy; 11631da177e4SLinus Torvalds to += copy; 11641da177e4SLinus Torvalds pos = copy; 11651da177e4SLinus Torvalds } 11661da177e4SLinus Torvalds 11671da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 11681da177e4SLinus Torvalds int end; 11691da177e4SLinus Torvalds 11701da177e4SLinus Torvalds BUG_TRAP(start <= offset + len); 11711da177e4SLinus Torvalds 11721da177e4SLinus Torvalds end = start + skb_shinfo(skb)->frags[i].size; 11731da177e4SLinus Torvalds if ((copy = end - offset) > 0) { 11741da177e4SLinus Torvalds unsigned int csum2; 11751da177e4SLinus Torvalds u8 *vaddr; 11761da177e4SLinus Torvalds skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 11771da177e4SLinus Torvalds 11781da177e4SLinus Torvalds if (copy > len) 11791da177e4SLinus Torvalds copy = len; 11801da177e4SLinus Torvalds vaddr = kmap_skb_frag(frag); 11811da177e4SLinus Torvalds csum2 = csum_partial_copy_nocheck(vaddr + 11821da177e4SLinus Torvalds frag->page_offset + 11831da177e4SLinus Torvalds offset - start, to, 11841da177e4SLinus Torvalds copy, 0); 11851da177e4SLinus Torvalds kunmap_skb_frag(vaddr); 11861da177e4SLinus Torvalds csum = csum_block_add(csum, csum2, pos); 11871da177e4SLinus Torvalds if (!(len -= copy)) 11881da177e4SLinus Torvalds return csum; 11891da177e4SLinus Torvalds offset += copy; 11901da177e4SLinus Torvalds to += copy; 11911da177e4SLinus Torvalds pos += copy; 11921da177e4SLinus Torvalds } 11931da177e4SLinus Torvalds start = end; 11941da177e4SLinus Torvalds } 11951da177e4SLinus Torvalds 11961da177e4SLinus Torvalds if (skb_shinfo(skb)->frag_list) { 11971da177e4SLinus Torvalds struct sk_buff *list = skb_shinfo(skb)->frag_list; 11981da177e4SLinus Torvalds 11991da177e4SLinus Torvalds for (; list; list = list->next) { 12001da177e4SLinus Torvalds unsigned int csum2; 12011da177e4SLinus Torvalds int end; 12021da177e4SLinus Torvalds 12031da177e4SLinus Torvalds BUG_TRAP(start <= offset + len); 12041da177e4SLinus Torvalds 12051da177e4SLinus Torvalds end = start + list->len; 12061da177e4SLinus Torvalds if ((copy = end - offset) > 0) { 12071da177e4SLinus Torvalds if (copy > len) 12081da177e4SLinus Torvalds copy = len; 12091da177e4SLinus Torvalds csum2 = skb_copy_and_csum_bits(list, 12101da177e4SLinus Torvalds offset - start, 12111da177e4SLinus Torvalds to, copy, 0); 12121da177e4SLinus Torvalds csum = csum_block_add(csum, csum2, pos); 12131da177e4SLinus Torvalds if ((len -= copy) == 0) 12141da177e4SLinus Torvalds return csum; 12151da177e4SLinus Torvalds offset += copy; 12161da177e4SLinus Torvalds to += copy; 12171da177e4SLinus Torvalds pos += copy; 12181da177e4SLinus Torvalds } 12191da177e4SLinus Torvalds start = end; 12201da177e4SLinus Torvalds } 12211da177e4SLinus Torvalds } 12221da177e4SLinus Torvalds if (len) 12231da177e4SLinus Torvalds BUG(); 12241da177e4SLinus Torvalds return csum; 12251da177e4SLinus Torvalds } 12261da177e4SLinus Torvalds 12271da177e4SLinus Torvalds void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to) 12281da177e4SLinus Torvalds { 12291da177e4SLinus Torvalds unsigned int csum; 12301da177e4SLinus Torvalds long csstart; 12311da177e4SLinus Torvalds 12321da177e4SLinus Torvalds if (skb->ip_summed == CHECKSUM_HW) 12331da177e4SLinus Torvalds csstart = skb->h.raw - skb->data; 12341da177e4SLinus Torvalds else 12351da177e4SLinus Torvalds csstart = skb_headlen(skb); 12361da177e4SLinus Torvalds 12371da177e4SLinus Torvalds if (csstart > skb_headlen(skb)) 12381da177e4SLinus Torvalds BUG(); 12391da177e4SLinus Torvalds 12401da177e4SLinus Torvalds memcpy(to, skb->data, csstart); 12411da177e4SLinus Torvalds 12421da177e4SLinus Torvalds csum = 0; 12431da177e4SLinus Torvalds if (csstart != skb->len) 12441da177e4SLinus Torvalds csum = skb_copy_and_csum_bits(skb, csstart, to + csstart, 12451da177e4SLinus Torvalds skb->len - csstart, 0); 12461da177e4SLinus Torvalds 12471da177e4SLinus Torvalds if (skb->ip_summed == CHECKSUM_HW) { 12481da177e4SLinus Torvalds long csstuff = csstart + skb->csum; 12491da177e4SLinus Torvalds 12501da177e4SLinus Torvalds *((unsigned short *)(to + csstuff)) = csum_fold(csum); 12511da177e4SLinus Torvalds } 12521da177e4SLinus Torvalds } 12531da177e4SLinus Torvalds 12541da177e4SLinus Torvalds /** 12551da177e4SLinus Torvalds * skb_dequeue - remove from the head of the queue 12561da177e4SLinus Torvalds * @list: list to dequeue from 12571da177e4SLinus Torvalds * 12581da177e4SLinus Torvalds * Remove the head of the list. The list lock is taken so the function 12591da177e4SLinus Torvalds * may be used safely with other locking list functions. The head item is 12601da177e4SLinus Torvalds * returned or %NULL if the list is empty. 12611da177e4SLinus Torvalds */ 12621da177e4SLinus Torvalds 12631da177e4SLinus Torvalds struct sk_buff *skb_dequeue(struct sk_buff_head *list) 12641da177e4SLinus Torvalds { 12651da177e4SLinus Torvalds unsigned long flags; 12661da177e4SLinus Torvalds struct sk_buff *result; 12671da177e4SLinus Torvalds 12681da177e4SLinus Torvalds spin_lock_irqsave(&list->lock, flags); 12691da177e4SLinus Torvalds result = __skb_dequeue(list); 12701da177e4SLinus Torvalds spin_unlock_irqrestore(&list->lock, flags); 12711da177e4SLinus Torvalds return result; 12721da177e4SLinus Torvalds } 12731da177e4SLinus Torvalds 12741da177e4SLinus Torvalds /** 12751da177e4SLinus Torvalds * skb_dequeue_tail - remove from the tail of the queue 12761da177e4SLinus Torvalds * @list: list to dequeue from 12771da177e4SLinus Torvalds * 12781da177e4SLinus Torvalds * Remove the tail of the list. The list lock is taken so the function 12791da177e4SLinus Torvalds * may be used safely with other locking list functions. The tail item is 12801da177e4SLinus Torvalds * returned or %NULL if the list is empty. 12811da177e4SLinus Torvalds */ 12821da177e4SLinus Torvalds struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list) 12831da177e4SLinus Torvalds { 12841da177e4SLinus Torvalds unsigned long flags; 12851da177e4SLinus Torvalds struct sk_buff *result; 12861da177e4SLinus Torvalds 12871da177e4SLinus Torvalds spin_lock_irqsave(&list->lock, flags); 12881da177e4SLinus Torvalds result = __skb_dequeue_tail(list); 12891da177e4SLinus Torvalds spin_unlock_irqrestore(&list->lock, flags); 12901da177e4SLinus Torvalds return result; 12911da177e4SLinus Torvalds } 12921da177e4SLinus Torvalds 12931da177e4SLinus Torvalds /** 12941da177e4SLinus Torvalds * skb_queue_purge - empty a list 12951da177e4SLinus Torvalds * @list: list to empty 12961da177e4SLinus Torvalds * 12971da177e4SLinus Torvalds * Delete all buffers on an &sk_buff list. Each buffer is removed from 12981da177e4SLinus Torvalds * the list and one reference dropped. This function takes the list 12991da177e4SLinus Torvalds * lock and is atomic with respect to other list locking functions. 13001da177e4SLinus Torvalds */ 13011da177e4SLinus Torvalds void skb_queue_purge(struct sk_buff_head *list) 13021da177e4SLinus Torvalds { 13031da177e4SLinus Torvalds struct sk_buff *skb; 13041da177e4SLinus Torvalds while ((skb = skb_dequeue(list)) != NULL) 13051da177e4SLinus Torvalds kfree_skb(skb); 13061da177e4SLinus Torvalds } 13071da177e4SLinus Torvalds 13081da177e4SLinus Torvalds /** 13091da177e4SLinus Torvalds * skb_queue_head - queue a buffer at the list head 13101da177e4SLinus Torvalds * @list: list to use 13111da177e4SLinus Torvalds * @newsk: buffer to queue 13121da177e4SLinus Torvalds * 13131da177e4SLinus Torvalds * Queue a buffer at the start of the list. This function takes the 13141da177e4SLinus Torvalds * list lock and can be used safely with other locking &sk_buff functions 13151da177e4SLinus Torvalds * safely. 13161da177e4SLinus Torvalds * 13171da177e4SLinus Torvalds * A buffer cannot be placed on two lists at the same time. 13181da177e4SLinus Torvalds */ 13191da177e4SLinus Torvalds void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk) 13201da177e4SLinus Torvalds { 13211da177e4SLinus Torvalds unsigned long flags; 13221da177e4SLinus Torvalds 13231da177e4SLinus Torvalds spin_lock_irqsave(&list->lock, flags); 13241da177e4SLinus Torvalds __skb_queue_head(list, newsk); 13251da177e4SLinus Torvalds spin_unlock_irqrestore(&list->lock, flags); 13261da177e4SLinus Torvalds } 13271da177e4SLinus Torvalds 13281da177e4SLinus Torvalds /** 13291da177e4SLinus Torvalds * skb_queue_tail - queue a buffer at the list tail 13301da177e4SLinus Torvalds * @list: list to use 13311da177e4SLinus Torvalds * @newsk: buffer to queue 13321da177e4SLinus Torvalds * 13331da177e4SLinus Torvalds * Queue a buffer at the tail of the list. This function takes the 13341da177e4SLinus Torvalds * list lock and can be used safely with other locking &sk_buff functions 13351da177e4SLinus Torvalds * safely. 13361da177e4SLinus Torvalds * 13371da177e4SLinus Torvalds * A buffer cannot be placed on two lists at the same time. 13381da177e4SLinus Torvalds */ 13391da177e4SLinus Torvalds void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk) 13401da177e4SLinus Torvalds { 13411da177e4SLinus Torvalds unsigned long flags; 13421da177e4SLinus Torvalds 13431da177e4SLinus Torvalds spin_lock_irqsave(&list->lock, flags); 13441da177e4SLinus Torvalds __skb_queue_tail(list, newsk); 13451da177e4SLinus Torvalds spin_unlock_irqrestore(&list->lock, flags); 13461da177e4SLinus Torvalds } 13471da177e4SLinus Torvalds /** 13481da177e4SLinus Torvalds * skb_unlink - remove a buffer from a list 13491da177e4SLinus Torvalds * @skb: buffer to remove 13501da177e4SLinus Torvalds * 13511da177e4SLinus Torvalds * Place a packet after a given packet in a list. The list locks are taken 13521da177e4SLinus Torvalds * and this function is atomic with respect to other list locked calls 13531da177e4SLinus Torvalds * 13541da177e4SLinus Torvalds * Works even without knowing the list it is sitting on, which can be 13551da177e4SLinus Torvalds * handy at times. It also means that THE LIST MUST EXIST when you 13561da177e4SLinus Torvalds * unlink. Thus a list must have its contents unlinked before it is 13571da177e4SLinus Torvalds * destroyed. 13581da177e4SLinus Torvalds */ 13591da177e4SLinus Torvalds void skb_unlink(struct sk_buff *skb) 13601da177e4SLinus Torvalds { 13611da177e4SLinus Torvalds struct sk_buff_head *list = skb->list; 13621da177e4SLinus Torvalds 13631da177e4SLinus Torvalds if (list) { 13641da177e4SLinus Torvalds unsigned long flags; 13651da177e4SLinus Torvalds 13661da177e4SLinus Torvalds spin_lock_irqsave(&list->lock, flags); 13671da177e4SLinus Torvalds if (skb->list == list) 13681da177e4SLinus Torvalds __skb_unlink(skb, skb->list); 13691da177e4SLinus Torvalds spin_unlock_irqrestore(&list->lock, flags); 13701da177e4SLinus Torvalds } 13711da177e4SLinus Torvalds } 13721da177e4SLinus Torvalds 13731da177e4SLinus Torvalds 13741da177e4SLinus Torvalds /** 13751da177e4SLinus Torvalds * skb_append - append a buffer 13761da177e4SLinus Torvalds * @old: buffer to insert after 13771da177e4SLinus Torvalds * @newsk: buffer to insert 13781da177e4SLinus Torvalds * 13791da177e4SLinus Torvalds * Place a packet after a given packet in a list. The list locks are taken 13801da177e4SLinus Torvalds * and this function is atomic with respect to other list locked calls. 13811da177e4SLinus Torvalds * A buffer cannot be placed on two lists at the same time. 13821da177e4SLinus Torvalds */ 13831da177e4SLinus Torvalds 13841da177e4SLinus Torvalds void skb_append(struct sk_buff *old, struct sk_buff *newsk) 13851da177e4SLinus Torvalds { 13861da177e4SLinus Torvalds unsigned long flags; 13871da177e4SLinus Torvalds 13881da177e4SLinus Torvalds spin_lock_irqsave(&old->list->lock, flags); 13891da177e4SLinus Torvalds __skb_append(old, newsk); 13901da177e4SLinus Torvalds spin_unlock_irqrestore(&old->list->lock, flags); 13911da177e4SLinus Torvalds } 13921da177e4SLinus Torvalds 13931da177e4SLinus Torvalds 13941da177e4SLinus Torvalds /** 13951da177e4SLinus Torvalds * skb_insert - insert a buffer 13961da177e4SLinus Torvalds * @old: buffer to insert before 13971da177e4SLinus Torvalds * @newsk: buffer to insert 13981da177e4SLinus Torvalds * 13991da177e4SLinus Torvalds * Place a packet before a given packet in a list. The list locks are taken 14001da177e4SLinus Torvalds * and this function is atomic with respect to other list locked calls 14011da177e4SLinus Torvalds * A buffer cannot be placed on two lists at the same time. 14021da177e4SLinus Torvalds */ 14031da177e4SLinus Torvalds 14041da177e4SLinus Torvalds void skb_insert(struct sk_buff *old, struct sk_buff *newsk) 14051da177e4SLinus Torvalds { 14061da177e4SLinus Torvalds unsigned long flags; 14071da177e4SLinus Torvalds 14081da177e4SLinus Torvalds spin_lock_irqsave(&old->list->lock, flags); 14091da177e4SLinus Torvalds __skb_insert(newsk, old->prev, old, old->list); 14101da177e4SLinus Torvalds spin_unlock_irqrestore(&old->list->lock, flags); 14111da177e4SLinus Torvalds } 14121da177e4SLinus Torvalds 14131da177e4SLinus Torvalds #if 0 14141da177e4SLinus Torvalds /* 14151da177e4SLinus Torvalds * Tune the memory allocator for a new MTU size. 14161da177e4SLinus Torvalds */ 14171da177e4SLinus Torvalds void skb_add_mtu(int mtu) 14181da177e4SLinus Torvalds { 14191da177e4SLinus Torvalds /* Must match allocation in alloc_skb */ 14201da177e4SLinus Torvalds mtu = SKB_DATA_ALIGN(mtu) + sizeof(struct skb_shared_info); 14211da177e4SLinus Torvalds 14221da177e4SLinus Torvalds kmem_add_cache_size(mtu); 14231da177e4SLinus Torvalds } 14241da177e4SLinus Torvalds #endif 14251da177e4SLinus Torvalds 14261da177e4SLinus Torvalds static inline void skb_split_inside_header(struct sk_buff *skb, 14271da177e4SLinus Torvalds struct sk_buff* skb1, 14281da177e4SLinus Torvalds const u32 len, const int pos) 14291da177e4SLinus Torvalds { 14301da177e4SLinus Torvalds int i; 14311da177e4SLinus Torvalds 14321da177e4SLinus Torvalds memcpy(skb_put(skb1, pos - len), skb->data + len, pos - len); 14331da177e4SLinus Torvalds 14341da177e4SLinus Torvalds /* And move data appendix as is. */ 14351da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) 14361da177e4SLinus Torvalds skb_shinfo(skb1)->frags[i] = skb_shinfo(skb)->frags[i]; 14371da177e4SLinus Torvalds 14381da177e4SLinus Torvalds skb_shinfo(skb1)->nr_frags = skb_shinfo(skb)->nr_frags; 14391da177e4SLinus Torvalds skb_shinfo(skb)->nr_frags = 0; 14401da177e4SLinus Torvalds skb1->data_len = skb->data_len; 14411da177e4SLinus Torvalds skb1->len += skb1->data_len; 14421da177e4SLinus Torvalds skb->data_len = 0; 14431da177e4SLinus Torvalds skb->len = len; 14441da177e4SLinus Torvalds skb->tail = skb->data + len; 14451da177e4SLinus Torvalds } 14461da177e4SLinus Torvalds 14471da177e4SLinus Torvalds static inline void skb_split_no_header(struct sk_buff *skb, 14481da177e4SLinus Torvalds struct sk_buff* skb1, 14491da177e4SLinus Torvalds const u32 len, int pos) 14501da177e4SLinus Torvalds { 14511da177e4SLinus Torvalds int i, k = 0; 14521da177e4SLinus Torvalds const int nfrags = skb_shinfo(skb)->nr_frags; 14531da177e4SLinus Torvalds 14541da177e4SLinus Torvalds skb_shinfo(skb)->nr_frags = 0; 14551da177e4SLinus Torvalds skb1->len = skb1->data_len = skb->len - len; 14561da177e4SLinus Torvalds skb->len = len; 14571da177e4SLinus Torvalds skb->data_len = len - pos; 14581da177e4SLinus Torvalds 14591da177e4SLinus Torvalds for (i = 0; i < nfrags; i++) { 14601da177e4SLinus Torvalds int size = skb_shinfo(skb)->frags[i].size; 14611da177e4SLinus Torvalds 14621da177e4SLinus Torvalds if (pos + size > len) { 14631da177e4SLinus Torvalds skb_shinfo(skb1)->frags[k] = skb_shinfo(skb)->frags[i]; 14641da177e4SLinus Torvalds 14651da177e4SLinus Torvalds if (pos < len) { 14661da177e4SLinus Torvalds /* Split frag. 14671da177e4SLinus Torvalds * We have two variants in this case: 14681da177e4SLinus Torvalds * 1. Move all the frag to the second 14691da177e4SLinus Torvalds * part, if it is possible. F.e. 14701da177e4SLinus Torvalds * this approach is mandatory for TUX, 14711da177e4SLinus Torvalds * where splitting is expensive. 14721da177e4SLinus Torvalds * 2. Split is accurately. We make this. 14731da177e4SLinus Torvalds */ 14741da177e4SLinus Torvalds get_page(skb_shinfo(skb)->frags[i].page); 14751da177e4SLinus Torvalds skb_shinfo(skb1)->frags[0].page_offset += len - pos; 14761da177e4SLinus Torvalds skb_shinfo(skb1)->frags[0].size -= len - pos; 14771da177e4SLinus Torvalds skb_shinfo(skb)->frags[i].size = len - pos; 14781da177e4SLinus Torvalds skb_shinfo(skb)->nr_frags++; 14791da177e4SLinus Torvalds } 14801da177e4SLinus Torvalds k++; 14811da177e4SLinus Torvalds } else 14821da177e4SLinus Torvalds skb_shinfo(skb)->nr_frags++; 14831da177e4SLinus Torvalds pos += size; 14841da177e4SLinus Torvalds } 14851da177e4SLinus Torvalds skb_shinfo(skb1)->nr_frags = k; 14861da177e4SLinus Torvalds } 14871da177e4SLinus Torvalds 14881da177e4SLinus Torvalds /** 14891da177e4SLinus Torvalds * skb_split - Split fragmented skb to two parts at length len. 14901da177e4SLinus Torvalds * @skb: the buffer to split 14911da177e4SLinus Torvalds * @skb1: the buffer to receive the second part 14921da177e4SLinus Torvalds * @len: new length for skb 14931da177e4SLinus Torvalds */ 14941da177e4SLinus Torvalds void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len) 14951da177e4SLinus Torvalds { 14961da177e4SLinus Torvalds int pos = skb_headlen(skb); 14971da177e4SLinus Torvalds 14981da177e4SLinus Torvalds if (len < pos) /* Split line is inside header. */ 14991da177e4SLinus Torvalds skb_split_inside_header(skb, skb1, len, pos); 15001da177e4SLinus Torvalds else /* Second chunk has no header, nothing to copy. */ 15011da177e4SLinus Torvalds skb_split_no_header(skb, skb1, len, pos); 15021da177e4SLinus Torvalds } 15031da177e4SLinus Torvalds 1504677e90edSThomas Graf /** 1505677e90edSThomas Graf * skb_prepare_seq_read - Prepare a sequential read of skb data 1506677e90edSThomas Graf * @skb: the buffer to read 1507677e90edSThomas Graf * @from: lower offset of data to be read 1508677e90edSThomas Graf * @to: upper offset of data to be read 1509677e90edSThomas Graf * @st: state variable 1510677e90edSThomas Graf * 1511677e90edSThomas Graf * Initializes the specified state variable. Must be called before 1512677e90edSThomas Graf * invoking skb_seq_read() for the first time. 1513677e90edSThomas Graf */ 1514677e90edSThomas Graf void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, 1515677e90edSThomas Graf unsigned int to, struct skb_seq_state *st) 1516677e90edSThomas Graf { 1517677e90edSThomas Graf st->lower_offset = from; 1518677e90edSThomas Graf st->upper_offset = to; 1519677e90edSThomas Graf st->root_skb = st->cur_skb = skb; 1520677e90edSThomas Graf st->frag_idx = st->stepped_offset = 0; 1521677e90edSThomas Graf st->frag_data = NULL; 1522677e90edSThomas Graf } 1523677e90edSThomas Graf 1524677e90edSThomas Graf /** 1525677e90edSThomas Graf * skb_seq_read - Sequentially read skb data 1526677e90edSThomas Graf * @consumed: number of bytes consumed by the caller so far 1527677e90edSThomas Graf * @data: destination pointer for data to be returned 1528677e90edSThomas Graf * @st: state variable 1529677e90edSThomas Graf * 1530677e90edSThomas Graf * Reads a block of skb data at &consumed relative to the 1531677e90edSThomas Graf * lower offset specified to skb_prepare_seq_read(). Assigns 1532677e90edSThomas Graf * the head of the data block to &data and returns the length 1533677e90edSThomas Graf * of the block or 0 if the end of the skb data or the upper 1534677e90edSThomas Graf * offset has been reached. 1535677e90edSThomas Graf * 1536677e90edSThomas Graf * The caller is not required to consume all of the data 1537677e90edSThomas Graf * returned, i.e. &consumed is typically set to the number 1538677e90edSThomas Graf * of bytes already consumed and the next call to 1539677e90edSThomas Graf * skb_seq_read() will return the remaining part of the block. 1540677e90edSThomas Graf * 1541677e90edSThomas Graf * Note: The size of each block of data returned can be arbitary, 1542677e90edSThomas Graf * this limitation is the cost for zerocopy seqeuental 1543677e90edSThomas Graf * reads of potentially non linear data. 1544677e90edSThomas Graf * 1545677e90edSThomas Graf * Note: Fragment lists within fragments are not implemented 1546677e90edSThomas Graf * at the moment, state->root_skb could be replaced with 1547677e90edSThomas Graf * a stack for this purpose. 1548677e90edSThomas Graf */ 1549677e90edSThomas Graf unsigned int skb_seq_read(unsigned int consumed, const u8 **data, 1550677e90edSThomas Graf struct skb_seq_state *st) 1551677e90edSThomas Graf { 1552677e90edSThomas Graf unsigned int block_limit, abs_offset = consumed + st->lower_offset; 1553677e90edSThomas Graf skb_frag_t *frag; 1554677e90edSThomas Graf 1555677e90edSThomas Graf if (unlikely(abs_offset >= st->upper_offset)) 1556677e90edSThomas Graf return 0; 1557677e90edSThomas Graf 1558677e90edSThomas Graf next_skb: 1559677e90edSThomas Graf block_limit = skb_headlen(st->cur_skb); 1560677e90edSThomas Graf 1561677e90edSThomas Graf if (abs_offset < block_limit) { 1562677e90edSThomas Graf *data = st->cur_skb->data + abs_offset; 1563677e90edSThomas Graf return block_limit - abs_offset; 1564677e90edSThomas Graf } 1565677e90edSThomas Graf 1566677e90edSThomas Graf if (st->frag_idx == 0 && !st->frag_data) 1567677e90edSThomas Graf st->stepped_offset += skb_headlen(st->cur_skb); 1568677e90edSThomas Graf 1569677e90edSThomas Graf while (st->frag_idx < skb_shinfo(st->cur_skb)->nr_frags) { 1570677e90edSThomas Graf frag = &skb_shinfo(st->cur_skb)->frags[st->frag_idx]; 1571677e90edSThomas Graf block_limit = frag->size + st->stepped_offset; 1572677e90edSThomas Graf 1573677e90edSThomas Graf if (abs_offset < block_limit) { 1574677e90edSThomas Graf if (!st->frag_data) 1575677e90edSThomas Graf st->frag_data = kmap_skb_frag(frag); 1576677e90edSThomas Graf 1577677e90edSThomas Graf *data = (u8 *) st->frag_data + frag->page_offset + 1578677e90edSThomas Graf (abs_offset - st->stepped_offset); 1579677e90edSThomas Graf 1580677e90edSThomas Graf return block_limit - abs_offset; 1581677e90edSThomas Graf } 1582677e90edSThomas Graf 1583677e90edSThomas Graf if (st->frag_data) { 1584677e90edSThomas Graf kunmap_skb_frag(st->frag_data); 1585677e90edSThomas Graf st->frag_data = NULL; 1586677e90edSThomas Graf } 1587677e90edSThomas Graf 1588677e90edSThomas Graf st->frag_idx++; 1589677e90edSThomas Graf st->stepped_offset += frag->size; 1590677e90edSThomas Graf } 1591677e90edSThomas Graf 1592677e90edSThomas Graf if (st->cur_skb->next) { 1593677e90edSThomas Graf st->cur_skb = st->cur_skb->next; 1594677e90edSThomas Graf st->frag_idx = 0; 1595677e90edSThomas Graf goto next_skb; 1596677e90edSThomas Graf } else if (st->root_skb == st->cur_skb && 1597677e90edSThomas Graf skb_shinfo(st->root_skb)->frag_list) { 1598677e90edSThomas Graf st->cur_skb = skb_shinfo(st->root_skb)->frag_list; 1599677e90edSThomas Graf goto next_skb; 1600677e90edSThomas Graf } 1601677e90edSThomas Graf 1602677e90edSThomas Graf return 0; 1603677e90edSThomas Graf } 1604677e90edSThomas Graf 1605677e90edSThomas Graf /** 1606677e90edSThomas Graf * skb_abort_seq_read - Abort a sequential read of skb data 1607677e90edSThomas Graf * @st: state variable 1608677e90edSThomas Graf * 1609677e90edSThomas Graf * Must be called if skb_seq_read() was not called until it 1610677e90edSThomas Graf * returned 0. 1611677e90edSThomas Graf */ 1612677e90edSThomas Graf void skb_abort_seq_read(struct skb_seq_state *st) 1613677e90edSThomas Graf { 1614677e90edSThomas Graf if (st->frag_data) 1615677e90edSThomas Graf kunmap_skb_frag(st->frag_data); 1616677e90edSThomas Graf } 1617677e90edSThomas Graf 16183fc7e8a6SThomas Graf #define TS_SKB_CB(state) ((struct skb_seq_state *) &((state)->cb)) 16193fc7e8a6SThomas Graf 16203fc7e8a6SThomas Graf static unsigned int skb_ts_get_next_block(unsigned int offset, const u8 **text, 16213fc7e8a6SThomas Graf struct ts_config *conf, 16223fc7e8a6SThomas Graf struct ts_state *state) 16233fc7e8a6SThomas Graf { 16243fc7e8a6SThomas Graf return skb_seq_read(offset, text, TS_SKB_CB(state)); 16253fc7e8a6SThomas Graf } 16263fc7e8a6SThomas Graf 16273fc7e8a6SThomas Graf static void skb_ts_finish(struct ts_config *conf, struct ts_state *state) 16283fc7e8a6SThomas Graf { 16293fc7e8a6SThomas Graf skb_abort_seq_read(TS_SKB_CB(state)); 16303fc7e8a6SThomas Graf } 16313fc7e8a6SThomas Graf 16323fc7e8a6SThomas Graf /** 16333fc7e8a6SThomas Graf * skb_find_text - Find a text pattern in skb data 16343fc7e8a6SThomas Graf * @skb: the buffer to look in 16353fc7e8a6SThomas Graf * @from: search offset 16363fc7e8a6SThomas Graf * @to: search limit 16373fc7e8a6SThomas Graf * @config: textsearch configuration 16383fc7e8a6SThomas Graf * @state: uninitialized textsearch state variable 16393fc7e8a6SThomas Graf * 16403fc7e8a6SThomas Graf * Finds a pattern in the skb data according to the specified 16413fc7e8a6SThomas Graf * textsearch configuration. Use textsearch_next() to retrieve 16423fc7e8a6SThomas Graf * subsequent occurrences of the pattern. Returns the offset 16433fc7e8a6SThomas Graf * to the first occurrence or UINT_MAX if no match was found. 16443fc7e8a6SThomas Graf */ 16453fc7e8a6SThomas Graf unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, 16463fc7e8a6SThomas Graf unsigned int to, struct ts_config *config, 16473fc7e8a6SThomas Graf struct ts_state *state) 16483fc7e8a6SThomas Graf { 16493fc7e8a6SThomas Graf config->get_next_block = skb_ts_get_next_block; 16503fc7e8a6SThomas Graf config->finish = skb_ts_finish; 16513fc7e8a6SThomas Graf 16523fc7e8a6SThomas Graf skb_prepare_seq_read(skb, from, to, TS_SKB_CB(state)); 16533fc7e8a6SThomas Graf 16543fc7e8a6SThomas Graf return textsearch_find(config, state); 16553fc7e8a6SThomas Graf } 16563fc7e8a6SThomas Graf 16571da177e4SLinus Torvalds void __init skb_init(void) 16581da177e4SLinus Torvalds { 16591da177e4SLinus Torvalds skbuff_head_cache = kmem_cache_create("skbuff_head_cache", 16601da177e4SLinus Torvalds sizeof(struct sk_buff), 16611da177e4SLinus Torvalds 0, 16621da177e4SLinus Torvalds SLAB_HWCACHE_ALIGN, 16631da177e4SLinus Torvalds NULL, NULL); 16641da177e4SLinus Torvalds if (!skbuff_head_cache) 16651da177e4SLinus Torvalds panic("cannot create skbuff cache"); 16661da177e4SLinus Torvalds } 16671da177e4SLinus Torvalds 16681da177e4SLinus Torvalds EXPORT_SYMBOL(___pskb_trim); 16691da177e4SLinus Torvalds EXPORT_SYMBOL(__kfree_skb); 16701da177e4SLinus Torvalds EXPORT_SYMBOL(__pskb_pull_tail); 16711da177e4SLinus Torvalds EXPORT_SYMBOL(alloc_skb); 16721da177e4SLinus Torvalds EXPORT_SYMBOL(pskb_copy); 16731da177e4SLinus Torvalds EXPORT_SYMBOL(pskb_expand_head); 16741da177e4SLinus Torvalds EXPORT_SYMBOL(skb_checksum); 16751da177e4SLinus Torvalds EXPORT_SYMBOL(skb_clone); 16761da177e4SLinus Torvalds EXPORT_SYMBOL(skb_clone_fraglist); 16771da177e4SLinus Torvalds EXPORT_SYMBOL(skb_copy); 16781da177e4SLinus Torvalds EXPORT_SYMBOL(skb_copy_and_csum_bits); 16791da177e4SLinus Torvalds EXPORT_SYMBOL(skb_copy_and_csum_dev); 16801da177e4SLinus Torvalds EXPORT_SYMBOL(skb_copy_bits); 16811da177e4SLinus Torvalds EXPORT_SYMBOL(skb_copy_expand); 16821da177e4SLinus Torvalds EXPORT_SYMBOL(skb_over_panic); 16831da177e4SLinus Torvalds EXPORT_SYMBOL(skb_pad); 16841da177e4SLinus Torvalds EXPORT_SYMBOL(skb_realloc_headroom); 16851da177e4SLinus Torvalds EXPORT_SYMBOL(skb_under_panic); 16861da177e4SLinus Torvalds EXPORT_SYMBOL(skb_dequeue); 16871da177e4SLinus Torvalds EXPORT_SYMBOL(skb_dequeue_tail); 16881da177e4SLinus Torvalds EXPORT_SYMBOL(skb_insert); 16891da177e4SLinus Torvalds EXPORT_SYMBOL(skb_queue_purge); 16901da177e4SLinus Torvalds EXPORT_SYMBOL(skb_queue_head); 16911da177e4SLinus Torvalds EXPORT_SYMBOL(skb_queue_tail); 16921da177e4SLinus Torvalds EXPORT_SYMBOL(skb_unlink); 16931da177e4SLinus Torvalds EXPORT_SYMBOL(skb_append); 16941da177e4SLinus Torvalds EXPORT_SYMBOL(skb_split); 1695677e90edSThomas Graf EXPORT_SYMBOL(skb_prepare_seq_read); 1696677e90edSThomas Graf EXPORT_SYMBOL(skb_seq_read); 1697677e90edSThomas Graf EXPORT_SYMBOL(skb_abort_seq_read); 16983fc7e8a6SThomas Graf EXPORT_SYMBOL(skb_find_text); 1699