115c9ac0cSSjur Braendeland /* 215c9ac0cSSjur Braendeland * Copyright (C) ST-Ericsson AB 2010 315c9ac0cSSjur Braendeland * Author: Sjur Brendeland/sjur.brandeland@stericsson.com 415c9ac0cSSjur Braendeland * License terms: GNU General Public License (GPL) version 2 515c9ac0cSSjur Braendeland */ 615c9ac0cSSjur Braendeland 7b31fa5baSJoe Perches #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ 8b31fa5baSJoe Perches 915c9ac0cSSjur Braendeland #include <linux/string.h> 1015c9ac0cSSjur Braendeland #include <linux/skbuff.h> 1115c9ac0cSSjur Braendeland #include <linux/hardirq.h> 12bc3b2d7fSPaul Gortmaker #include <linux/export.h> 1315c9ac0cSSjur Braendeland #include <net/caif/cfpkt.h> 1415c9ac0cSSjur Braendeland 1524e263adSSjur Braendeland #define PKT_PREFIX 48 162aa40aefSSjur Braendeland #define PKT_POSTFIX 2 1715c9ac0cSSjur Braendeland #define PKT_LEN_WHEN_EXTENDING 128 18b31fa5baSJoe Perches #define PKT_ERROR(pkt, errmsg) \ 19b31fa5baSJoe Perches do { \ 2015c9ac0cSSjur Braendeland cfpkt_priv(pkt)->erronous = true; \ 2115c9ac0cSSjur Braendeland skb_reset_tail_pointer(&pkt->skb); \ 22b31fa5baSJoe Perches pr_warn(errmsg); \ 2315c9ac0cSSjur Braendeland } while (0) 2415c9ac0cSSjur Braendeland 2515c9ac0cSSjur Braendeland struct cfpktq { 2615c9ac0cSSjur Braendeland struct sk_buff_head head; 2715c9ac0cSSjur Braendeland atomic_t count; 2815c9ac0cSSjur Braendeland /* Lock protects count updates */ 2915c9ac0cSSjur Braendeland spinlock_t lock; 3015c9ac0cSSjur Braendeland }; 3115c9ac0cSSjur Braendeland 3215c9ac0cSSjur Braendeland /* 3315c9ac0cSSjur Braendeland * net/caif/ is generic and does not 3415c9ac0cSSjur Braendeland * understand SKB, so we do this typecast 3515c9ac0cSSjur Braendeland */ 3615c9ac0cSSjur Braendeland struct cfpkt { 3715c9ac0cSSjur Braendeland struct sk_buff skb; 3815c9ac0cSSjur Braendeland }; 3915c9ac0cSSjur Braendeland 4015c9ac0cSSjur Braendeland /* Private data inside SKB */ 4115c9ac0cSSjur Braendeland struct cfpkt_priv_data { 4215c9ac0cSSjur Braendeland struct dev_info dev_info; 4315c9ac0cSSjur Braendeland bool erronous; 4415c9ac0cSSjur Braendeland }; 4515c9ac0cSSjur Braendeland 4673d6ac63SStephen Hemminger static inline struct cfpkt_priv_data *cfpkt_priv(struct cfpkt *pkt) 4715c9ac0cSSjur Braendeland { 4815c9ac0cSSjur Braendeland return (struct cfpkt_priv_data *) pkt->skb.cb; 4915c9ac0cSSjur Braendeland } 5015c9ac0cSSjur Braendeland 5173d6ac63SStephen Hemminger static inline bool is_erronous(struct cfpkt *pkt) 5215c9ac0cSSjur Braendeland { 5315c9ac0cSSjur Braendeland return cfpkt_priv(pkt)->erronous; 5415c9ac0cSSjur Braendeland } 5515c9ac0cSSjur Braendeland 5673d6ac63SStephen Hemminger static inline struct sk_buff *pkt_to_skb(struct cfpkt *pkt) 5715c9ac0cSSjur Braendeland { 5815c9ac0cSSjur Braendeland return &pkt->skb; 5915c9ac0cSSjur Braendeland } 6015c9ac0cSSjur Braendeland 6173d6ac63SStephen Hemminger static inline struct cfpkt *skb_to_pkt(struct sk_buff *skb) 6215c9ac0cSSjur Braendeland { 6315c9ac0cSSjur Braendeland return (struct cfpkt *) skb; 6415c9ac0cSSjur Braendeland } 6515c9ac0cSSjur Braendeland 6615c9ac0cSSjur Braendeland 6715c9ac0cSSjur Braendeland struct cfpkt *cfpkt_fromnative(enum caif_direction dir, void *nativepkt) 6815c9ac0cSSjur Braendeland { 6915c9ac0cSSjur Braendeland struct cfpkt *pkt = skb_to_pkt(nativepkt); 7015c9ac0cSSjur Braendeland cfpkt_priv(pkt)->erronous = false; 7115c9ac0cSSjur Braendeland return pkt; 7215c9ac0cSSjur Braendeland } 7315c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_fromnative); 7415c9ac0cSSjur Braendeland 7515c9ac0cSSjur Braendeland void *cfpkt_tonative(struct cfpkt *pkt) 7615c9ac0cSSjur Braendeland { 7715c9ac0cSSjur Braendeland return (void *) pkt; 7815c9ac0cSSjur Braendeland } 7915c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_tonative); 8015c9ac0cSSjur Braendeland 8115c9ac0cSSjur Braendeland static struct cfpkt *cfpkt_create_pfx(u16 len, u16 pfx) 8215c9ac0cSSjur Braendeland { 8315c9ac0cSSjur Braendeland struct sk_buff *skb; 8415c9ac0cSSjur Braendeland 8515c9ac0cSSjur Braendeland if (likely(in_interrupt())) 8615c9ac0cSSjur Braendeland skb = alloc_skb(len + pfx, GFP_ATOMIC); 8715c9ac0cSSjur Braendeland else 8815c9ac0cSSjur Braendeland skb = alloc_skb(len + pfx, GFP_KERNEL); 8915c9ac0cSSjur Braendeland 9015c9ac0cSSjur Braendeland if (unlikely(skb == NULL)) 9115c9ac0cSSjur Braendeland return NULL; 9215c9ac0cSSjur Braendeland 9315c9ac0cSSjur Braendeland skb_reserve(skb, pfx); 9415c9ac0cSSjur Braendeland return skb_to_pkt(skb); 9515c9ac0cSSjur Braendeland } 9615c9ac0cSSjur Braendeland 9715c9ac0cSSjur Braendeland inline struct cfpkt *cfpkt_create(u16 len) 9815c9ac0cSSjur Braendeland { 9915c9ac0cSSjur Braendeland return cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX); 10015c9ac0cSSjur Braendeland } 10115c9ac0cSSjur Braendeland 10215c9ac0cSSjur Braendeland void cfpkt_destroy(struct cfpkt *pkt) 10315c9ac0cSSjur Braendeland { 10415c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 10515c9ac0cSSjur Braendeland kfree_skb(skb); 10615c9ac0cSSjur Braendeland } 1073f874adcSsjur.brandeland@stericsson.com 10815c9ac0cSSjur Braendeland 10915c9ac0cSSjur Braendeland inline bool cfpkt_more(struct cfpkt *pkt) 11015c9ac0cSSjur Braendeland { 11115c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 11215c9ac0cSSjur Braendeland return skb->len > 0; 11315c9ac0cSSjur Braendeland } 1143f874adcSsjur.brandeland@stericsson.com 11515c9ac0cSSjur Braendeland 11615c9ac0cSSjur Braendeland int cfpkt_peek_head(struct cfpkt *pkt, void *data, u16 len) 11715c9ac0cSSjur Braendeland { 11815c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 11915c9ac0cSSjur Braendeland if (skb_headlen(skb) >= len) { 12015c9ac0cSSjur Braendeland memcpy(data, skb->data, len); 12115c9ac0cSSjur Braendeland return 0; 12215c9ac0cSSjur Braendeland } 12315c9ac0cSSjur Braendeland return !cfpkt_extr_head(pkt, data, len) && 12415c9ac0cSSjur Braendeland !cfpkt_add_head(pkt, data, len); 12515c9ac0cSSjur Braendeland } 12615c9ac0cSSjur Braendeland 12715c9ac0cSSjur Braendeland int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len) 12815c9ac0cSSjur Braendeland { 12915c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 13015c9ac0cSSjur Braendeland u8 *from; 13115c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 13215c9ac0cSSjur Braendeland return -EPROTO; 13315c9ac0cSSjur Braendeland 13415c9ac0cSSjur Braendeland if (unlikely(len > skb->len)) { 135b31fa5baSJoe Perches PKT_ERROR(pkt, "read beyond end of packet\n"); 13615c9ac0cSSjur Braendeland return -EPROTO; 13715c9ac0cSSjur Braendeland } 13815c9ac0cSSjur Braendeland 13915c9ac0cSSjur Braendeland if (unlikely(len > skb_headlen(skb))) { 14015c9ac0cSSjur Braendeland if (unlikely(skb_linearize(skb) != 0)) { 141b31fa5baSJoe Perches PKT_ERROR(pkt, "linearize failed\n"); 14215c9ac0cSSjur Braendeland return -EPROTO; 14315c9ac0cSSjur Braendeland } 14415c9ac0cSSjur Braendeland } 14515c9ac0cSSjur Braendeland from = skb_pull(skb, len); 14615c9ac0cSSjur Braendeland from -= len; 147200c5a3bSsjur.brandeland@stericsson.com if (data) 14815c9ac0cSSjur Braendeland memcpy(data, from, len); 14915c9ac0cSSjur Braendeland return 0; 15015c9ac0cSSjur Braendeland } 15115c9ac0cSSjur Braendeland 15215c9ac0cSSjur Braendeland int cfpkt_extr_trail(struct cfpkt *pkt, void *dta, u16 len) 15315c9ac0cSSjur Braendeland { 15415c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 15515c9ac0cSSjur Braendeland u8 *data = dta; 15615c9ac0cSSjur Braendeland u8 *from; 15715c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 15815c9ac0cSSjur Braendeland return -EPROTO; 15915c9ac0cSSjur Braendeland 16015c9ac0cSSjur Braendeland if (unlikely(skb_linearize(skb) != 0)) { 161b31fa5baSJoe Perches PKT_ERROR(pkt, "linearize failed\n"); 16215c9ac0cSSjur Braendeland return -EPROTO; 16315c9ac0cSSjur Braendeland } 16415c9ac0cSSjur Braendeland if (unlikely(skb->data + len > skb_tail_pointer(skb))) { 165b31fa5baSJoe Perches PKT_ERROR(pkt, "read beyond end of packet\n"); 16615c9ac0cSSjur Braendeland return -EPROTO; 16715c9ac0cSSjur Braendeland } 16815c9ac0cSSjur Braendeland from = skb_tail_pointer(skb) - len; 16915c9ac0cSSjur Braendeland skb_trim(skb, skb->len - len); 17015c9ac0cSSjur Braendeland memcpy(data, from, len); 17115c9ac0cSSjur Braendeland return 0; 17215c9ac0cSSjur Braendeland } 1733f874adcSsjur.brandeland@stericsson.com 17415c9ac0cSSjur Braendeland 17515c9ac0cSSjur Braendeland int cfpkt_pad_trail(struct cfpkt *pkt, u16 len) 17615c9ac0cSSjur Braendeland { 17715c9ac0cSSjur Braendeland return cfpkt_add_body(pkt, NULL, len); 17815c9ac0cSSjur Braendeland } 1793f874adcSsjur.brandeland@stericsson.com 18015c9ac0cSSjur Braendeland 18115c9ac0cSSjur Braendeland int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len) 18215c9ac0cSSjur Braendeland { 18315c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 18415c9ac0cSSjur Braendeland struct sk_buff *lastskb; 18515c9ac0cSSjur Braendeland u8 *to; 18615c9ac0cSSjur Braendeland u16 addlen = 0; 18715c9ac0cSSjur Braendeland 18815c9ac0cSSjur Braendeland 18915c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 19015c9ac0cSSjur Braendeland return -EPROTO; 19115c9ac0cSSjur Braendeland 19215c9ac0cSSjur Braendeland lastskb = skb; 19315c9ac0cSSjur Braendeland 19415c9ac0cSSjur Braendeland /* Check whether we need to add space at the tail */ 19515c9ac0cSSjur Braendeland if (unlikely(skb_tailroom(skb) < len)) { 19615c9ac0cSSjur Braendeland if (likely(len < PKT_LEN_WHEN_EXTENDING)) 19715c9ac0cSSjur Braendeland addlen = PKT_LEN_WHEN_EXTENDING; 19815c9ac0cSSjur Braendeland else 19915c9ac0cSSjur Braendeland addlen = len; 20015c9ac0cSSjur Braendeland } 20115c9ac0cSSjur Braendeland 20215c9ac0cSSjur Braendeland /* Check whether we need to change the SKB before writing to the tail */ 20315c9ac0cSSjur Braendeland if (unlikely((addlen > 0) || skb_cloned(skb) || skb_shared(skb))) { 20415c9ac0cSSjur Braendeland 20515c9ac0cSSjur Braendeland /* Make sure data is writable */ 20615c9ac0cSSjur Braendeland if (unlikely(skb_cow_data(skb, addlen, &lastskb) < 0)) { 207b31fa5baSJoe Perches PKT_ERROR(pkt, "cow failed\n"); 20815c9ac0cSSjur Braendeland return -EPROTO; 20915c9ac0cSSjur Braendeland } 21015c9ac0cSSjur Braendeland /* 21115c9ac0cSSjur Braendeland * Is the SKB non-linear after skb_cow_data()? If so, we are 21215c9ac0cSSjur Braendeland * going to add data to the last SKB, so we need to adjust 21315c9ac0cSSjur Braendeland * lengths of the top SKB. 21415c9ac0cSSjur Braendeland */ 21515c9ac0cSSjur Braendeland if (lastskb != skb) { 216b31fa5baSJoe Perches pr_warn("Packet is non-linear\n"); 21715c9ac0cSSjur Braendeland skb->len += len; 21815c9ac0cSSjur Braendeland skb->data_len += len; 21915c9ac0cSSjur Braendeland } 22015c9ac0cSSjur Braendeland } 22115c9ac0cSSjur Braendeland 22215c9ac0cSSjur Braendeland /* All set to put the last SKB and optionally write data there. */ 22315c9ac0cSSjur Braendeland to = skb_put(lastskb, len); 22415c9ac0cSSjur Braendeland if (likely(data)) 22515c9ac0cSSjur Braendeland memcpy(to, data, len); 22615c9ac0cSSjur Braendeland return 0; 22715c9ac0cSSjur Braendeland } 22815c9ac0cSSjur Braendeland 22915c9ac0cSSjur Braendeland inline int cfpkt_addbdy(struct cfpkt *pkt, u8 data) 23015c9ac0cSSjur Braendeland { 23115c9ac0cSSjur Braendeland return cfpkt_add_body(pkt, &data, 1); 23215c9ac0cSSjur Braendeland } 23315c9ac0cSSjur Braendeland 23415c9ac0cSSjur Braendeland int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len) 23515c9ac0cSSjur Braendeland { 23615c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 23715c9ac0cSSjur Braendeland struct sk_buff *lastskb; 23815c9ac0cSSjur Braendeland u8 *to; 23915c9ac0cSSjur Braendeland const u8 *data = data2; 240638e628aSSjur Braendeland int ret; 24115c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 24215c9ac0cSSjur Braendeland return -EPROTO; 24315c9ac0cSSjur Braendeland if (unlikely(skb_headroom(skb) < len)) { 244b31fa5baSJoe Perches PKT_ERROR(pkt, "no headroom\n"); 24515c9ac0cSSjur Braendeland return -EPROTO; 24615c9ac0cSSjur Braendeland } 24715c9ac0cSSjur Braendeland 24815c9ac0cSSjur Braendeland /* Make sure data is writable */ 249638e628aSSjur Braendeland ret = skb_cow_data(skb, 0, &lastskb); 250638e628aSSjur Braendeland if (unlikely(ret < 0)) { 251b31fa5baSJoe Perches PKT_ERROR(pkt, "cow failed\n"); 252638e628aSSjur Braendeland return ret; 25315c9ac0cSSjur Braendeland } 25415c9ac0cSSjur Braendeland 25515c9ac0cSSjur Braendeland to = skb_push(skb, len); 25615c9ac0cSSjur Braendeland memcpy(to, data, len); 25715c9ac0cSSjur Braendeland return 0; 25815c9ac0cSSjur Braendeland } 2593f874adcSsjur.brandeland@stericsson.com 26015c9ac0cSSjur Braendeland 26115c9ac0cSSjur Braendeland inline int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len) 26215c9ac0cSSjur Braendeland { 26315c9ac0cSSjur Braendeland return cfpkt_add_body(pkt, data, len); 26415c9ac0cSSjur Braendeland } 2653f874adcSsjur.brandeland@stericsson.com 26615c9ac0cSSjur Braendeland 26715c9ac0cSSjur Braendeland inline u16 cfpkt_getlen(struct cfpkt *pkt) 26815c9ac0cSSjur Braendeland { 26915c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 27015c9ac0cSSjur Braendeland return skb->len; 27115c9ac0cSSjur Braendeland } 2723f874adcSsjur.brandeland@stericsson.com 27315c9ac0cSSjur Braendeland 27415c9ac0cSSjur Braendeland inline u16 cfpkt_iterate(struct cfpkt *pkt, 27515c9ac0cSSjur Braendeland u16 (*iter_func)(u16, void *, u16), 27615c9ac0cSSjur Braendeland u16 data) 27715c9ac0cSSjur Braendeland { 27815c9ac0cSSjur Braendeland /* 27915c9ac0cSSjur Braendeland * Don't care about the performance hit of linearizing, 28015c9ac0cSSjur Braendeland * Checksum should not be used on high-speed interfaces anyway. 28115c9ac0cSSjur Braendeland */ 28215c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 28315c9ac0cSSjur Braendeland return -EPROTO; 28415c9ac0cSSjur Braendeland if (unlikely(skb_linearize(&pkt->skb) != 0)) { 285b31fa5baSJoe Perches PKT_ERROR(pkt, "linearize failed\n"); 28615c9ac0cSSjur Braendeland return -EPROTO; 28715c9ac0cSSjur Braendeland } 28815c9ac0cSSjur Braendeland return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt)); 28915c9ac0cSSjur Braendeland } 2903f874adcSsjur.brandeland@stericsson.com 29115c9ac0cSSjur Braendeland 29215c9ac0cSSjur Braendeland int cfpkt_setlen(struct cfpkt *pkt, u16 len) 29315c9ac0cSSjur Braendeland { 29415c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 29515c9ac0cSSjur Braendeland 29615c9ac0cSSjur Braendeland 29715c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 29815c9ac0cSSjur Braendeland return -EPROTO; 29915c9ac0cSSjur Braendeland 30015c9ac0cSSjur Braendeland if (likely(len <= skb->len)) { 30115c9ac0cSSjur Braendeland if (unlikely(skb->data_len)) 30215c9ac0cSSjur Braendeland ___pskb_trim(skb, len); 30315c9ac0cSSjur Braendeland else 30415c9ac0cSSjur Braendeland skb_trim(skb, len); 30515c9ac0cSSjur Braendeland 30615c9ac0cSSjur Braendeland return cfpkt_getlen(pkt); 30715c9ac0cSSjur Braendeland } 30815c9ac0cSSjur Braendeland 30915c9ac0cSSjur Braendeland /* Need to expand SKB */ 31015c9ac0cSSjur Braendeland if (unlikely(!cfpkt_pad_trail(pkt, len - skb->len))) 311b31fa5baSJoe Perches PKT_ERROR(pkt, "skb_pad_trail failed\n"); 31215c9ac0cSSjur Braendeland 31315c9ac0cSSjur Braendeland return cfpkt_getlen(pkt); 31415c9ac0cSSjur Braendeland } 31515c9ac0cSSjur Braendeland 31615c9ac0cSSjur Braendeland struct cfpkt *cfpkt_append(struct cfpkt *dstpkt, 31715c9ac0cSSjur Braendeland struct cfpkt *addpkt, 31815c9ac0cSSjur Braendeland u16 expectlen) 31915c9ac0cSSjur Braendeland { 32015c9ac0cSSjur Braendeland struct sk_buff *dst = pkt_to_skb(dstpkt); 32115c9ac0cSSjur Braendeland struct sk_buff *add = pkt_to_skb(addpkt); 32215c9ac0cSSjur Braendeland u16 addlen = skb_headlen(add); 32315c9ac0cSSjur Braendeland u16 neededtailspace; 32415c9ac0cSSjur Braendeland struct sk_buff *tmp; 32515c9ac0cSSjur Braendeland u16 dstlen; 32615c9ac0cSSjur Braendeland u16 createlen; 32715c9ac0cSSjur Braendeland if (unlikely(is_erronous(dstpkt) || is_erronous(addpkt))) { 32815c9ac0cSSjur Braendeland return dstpkt; 32915c9ac0cSSjur Braendeland } 33015c9ac0cSSjur Braendeland if (expectlen > addlen) 33115c9ac0cSSjur Braendeland neededtailspace = expectlen; 33215c9ac0cSSjur Braendeland else 33315c9ac0cSSjur Braendeland neededtailspace = addlen; 33415c9ac0cSSjur Braendeland 33515c9ac0cSSjur Braendeland if (dst->tail + neededtailspace > dst->end) { 33615c9ac0cSSjur Braendeland /* Create a dumplicate of 'dst' with more tail space */ 337638e628aSSjur Braendeland struct cfpkt *tmppkt; 33815c9ac0cSSjur Braendeland dstlen = skb_headlen(dst); 33915c9ac0cSSjur Braendeland createlen = dstlen + neededtailspace; 340638e628aSSjur Braendeland tmppkt = cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX); 341638e628aSSjur Braendeland if (tmppkt == NULL) 34215c9ac0cSSjur Braendeland return NULL; 343638e628aSSjur Braendeland tmp = pkt_to_skb(tmppkt); 34415c9ac0cSSjur Braendeland skb_set_tail_pointer(tmp, dstlen); 34515c9ac0cSSjur Braendeland tmp->len = dstlen; 34615c9ac0cSSjur Braendeland memcpy(tmp->data, dst->data, dstlen); 34715c9ac0cSSjur Braendeland cfpkt_destroy(dstpkt); 34815c9ac0cSSjur Braendeland dst = tmp; 34915c9ac0cSSjur Braendeland } 35015c9ac0cSSjur Braendeland memcpy(skb_tail_pointer(dst), add->data, skb_headlen(add)); 35115c9ac0cSSjur Braendeland cfpkt_destroy(addpkt); 35215c9ac0cSSjur Braendeland dst->tail += addlen; 35315c9ac0cSSjur Braendeland dst->len += addlen; 35415c9ac0cSSjur Braendeland return skb_to_pkt(dst); 35515c9ac0cSSjur Braendeland } 35615c9ac0cSSjur Braendeland 35715c9ac0cSSjur Braendeland struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos) 35815c9ac0cSSjur Braendeland { 35915c9ac0cSSjur Braendeland struct sk_buff *skb2; 36015c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 361638e628aSSjur Braendeland struct cfpkt *tmppkt; 36215c9ac0cSSjur Braendeland u8 *split = skb->data + pos; 36315c9ac0cSSjur Braendeland u16 len2nd = skb_tail_pointer(skb) - split; 36415c9ac0cSSjur Braendeland 36515c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 36615c9ac0cSSjur Braendeland return NULL; 36715c9ac0cSSjur Braendeland 36815c9ac0cSSjur Braendeland if (skb->data + pos > skb_tail_pointer(skb)) { 369b31fa5baSJoe Perches PKT_ERROR(pkt, "trying to split beyond end of packet\n"); 37015c9ac0cSSjur Braendeland return NULL; 37115c9ac0cSSjur Braendeland } 37215c9ac0cSSjur Braendeland 37315c9ac0cSSjur Braendeland /* Create a new packet for the second part of the data */ 374638e628aSSjur Braendeland tmppkt = cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX, 375638e628aSSjur Braendeland PKT_PREFIX); 376638e628aSSjur Braendeland if (tmppkt == NULL) 377638e628aSSjur Braendeland return NULL; 378638e628aSSjur Braendeland skb2 = pkt_to_skb(tmppkt); 379638e628aSSjur Braendeland 38015c9ac0cSSjur Braendeland 38115c9ac0cSSjur Braendeland if (skb2 == NULL) 38215c9ac0cSSjur Braendeland return NULL; 38315c9ac0cSSjur Braendeland 38415c9ac0cSSjur Braendeland /* Reduce the length of the original packet */ 38515c9ac0cSSjur Braendeland skb_set_tail_pointer(skb, pos); 38615c9ac0cSSjur Braendeland skb->len = pos; 38715c9ac0cSSjur Braendeland 38815c9ac0cSSjur Braendeland memcpy(skb2->data, split, len2nd); 38915c9ac0cSSjur Braendeland skb2->tail += len2nd; 39015c9ac0cSSjur Braendeland skb2->len += len2nd; 39115c9ac0cSSjur Braendeland return skb_to_pkt(skb2); 39215c9ac0cSSjur Braendeland } 39315c9ac0cSSjur Braendeland 39473d6ac63SStephen Hemminger bool cfpkt_erroneous(struct cfpkt *pkt) 39515c9ac0cSSjur Braendeland { 39615c9ac0cSSjur Braendeland return cfpkt_priv(pkt)->erronous; 39715c9ac0cSSjur Braendeland } 39815c9ac0cSSjur Braendeland 39915c9ac0cSSjur Braendeland struct caif_payload_info *cfpkt_info(struct cfpkt *pkt) 40015c9ac0cSSjur Braendeland { 40115c9ac0cSSjur Braendeland return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb; 40215c9ac0cSSjur Braendeland } 403