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> 1215c9ac0cSSjur Braendeland #include <net/caif/cfpkt.h> 1315c9ac0cSSjur Braendeland 1424e263adSSjur Braendeland #define PKT_PREFIX 48 152aa40aefSSjur Braendeland #define PKT_POSTFIX 2 1615c9ac0cSSjur Braendeland #define PKT_LEN_WHEN_EXTENDING 128 17b31fa5baSJoe Perches #define PKT_ERROR(pkt, errmsg) \ 18b31fa5baSJoe Perches do { \ 1915c9ac0cSSjur Braendeland cfpkt_priv(pkt)->erronous = true; \ 2015c9ac0cSSjur Braendeland skb_reset_tail_pointer(&pkt->skb); \ 21b31fa5baSJoe Perches pr_warn(errmsg); \ 2215c9ac0cSSjur Braendeland } while (0) 2315c9ac0cSSjur Braendeland 2415c9ac0cSSjur Braendeland struct cfpktq { 2515c9ac0cSSjur Braendeland struct sk_buff_head head; 2615c9ac0cSSjur Braendeland atomic_t count; 2715c9ac0cSSjur Braendeland /* Lock protects count updates */ 2815c9ac0cSSjur Braendeland spinlock_t lock; 2915c9ac0cSSjur Braendeland }; 3015c9ac0cSSjur Braendeland 3115c9ac0cSSjur Braendeland /* 3215c9ac0cSSjur Braendeland * net/caif/ is generic and does not 3315c9ac0cSSjur Braendeland * understand SKB, so we do this typecast 3415c9ac0cSSjur Braendeland */ 3515c9ac0cSSjur Braendeland struct cfpkt { 3615c9ac0cSSjur Braendeland struct sk_buff skb; 3715c9ac0cSSjur Braendeland }; 3815c9ac0cSSjur Braendeland 3915c9ac0cSSjur Braendeland /* Private data inside SKB */ 4015c9ac0cSSjur Braendeland struct cfpkt_priv_data { 4115c9ac0cSSjur Braendeland struct dev_info dev_info; 4215c9ac0cSSjur Braendeland bool erronous; 4315c9ac0cSSjur Braendeland }; 4415c9ac0cSSjur Braendeland 4573d6ac63SStephen Hemminger static inline struct cfpkt_priv_data *cfpkt_priv(struct cfpkt *pkt) 4615c9ac0cSSjur Braendeland { 4715c9ac0cSSjur Braendeland return (struct cfpkt_priv_data *) pkt->skb.cb; 4815c9ac0cSSjur Braendeland } 4915c9ac0cSSjur Braendeland 5073d6ac63SStephen Hemminger static inline bool is_erronous(struct cfpkt *pkt) 5115c9ac0cSSjur Braendeland { 5215c9ac0cSSjur Braendeland return cfpkt_priv(pkt)->erronous; 5315c9ac0cSSjur Braendeland } 5415c9ac0cSSjur Braendeland 5573d6ac63SStephen Hemminger static inline struct sk_buff *pkt_to_skb(struct cfpkt *pkt) 5615c9ac0cSSjur Braendeland { 5715c9ac0cSSjur Braendeland return &pkt->skb; 5815c9ac0cSSjur Braendeland } 5915c9ac0cSSjur Braendeland 6073d6ac63SStephen Hemminger static inline struct cfpkt *skb_to_pkt(struct sk_buff *skb) 6115c9ac0cSSjur Braendeland { 6215c9ac0cSSjur Braendeland return (struct cfpkt *) skb; 6315c9ac0cSSjur Braendeland } 6415c9ac0cSSjur Braendeland 6515c9ac0cSSjur Braendeland 6615c9ac0cSSjur Braendeland struct cfpkt *cfpkt_fromnative(enum caif_direction dir, void *nativepkt) 6715c9ac0cSSjur Braendeland { 6815c9ac0cSSjur Braendeland struct cfpkt *pkt = skb_to_pkt(nativepkt); 6915c9ac0cSSjur Braendeland cfpkt_priv(pkt)->erronous = false; 7015c9ac0cSSjur Braendeland return pkt; 7115c9ac0cSSjur Braendeland } 7215c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_fromnative); 7315c9ac0cSSjur Braendeland 7415c9ac0cSSjur Braendeland void *cfpkt_tonative(struct cfpkt *pkt) 7515c9ac0cSSjur Braendeland { 7615c9ac0cSSjur Braendeland return (void *) pkt; 7715c9ac0cSSjur Braendeland } 7815c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_tonative); 7915c9ac0cSSjur Braendeland 8015c9ac0cSSjur Braendeland static struct cfpkt *cfpkt_create_pfx(u16 len, u16 pfx) 8115c9ac0cSSjur Braendeland { 8215c9ac0cSSjur Braendeland struct sk_buff *skb; 8315c9ac0cSSjur Braendeland 8415c9ac0cSSjur Braendeland if (likely(in_interrupt())) 8515c9ac0cSSjur Braendeland skb = alloc_skb(len + pfx, GFP_ATOMIC); 8615c9ac0cSSjur Braendeland else 8715c9ac0cSSjur Braendeland skb = alloc_skb(len + pfx, GFP_KERNEL); 8815c9ac0cSSjur Braendeland 8915c9ac0cSSjur Braendeland if (unlikely(skb == NULL)) 9015c9ac0cSSjur Braendeland return NULL; 9115c9ac0cSSjur Braendeland 9215c9ac0cSSjur Braendeland skb_reserve(skb, pfx); 9315c9ac0cSSjur Braendeland return skb_to_pkt(skb); 9415c9ac0cSSjur Braendeland } 9515c9ac0cSSjur Braendeland 9615c9ac0cSSjur Braendeland inline struct cfpkt *cfpkt_create(u16 len) 9715c9ac0cSSjur Braendeland { 9815c9ac0cSSjur Braendeland return cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX); 9915c9ac0cSSjur Braendeland } 10015c9ac0cSSjur Braendeland 10115c9ac0cSSjur Braendeland void cfpkt_destroy(struct cfpkt *pkt) 10215c9ac0cSSjur Braendeland { 10315c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 10415c9ac0cSSjur Braendeland kfree_skb(skb); 10515c9ac0cSSjur Braendeland } 1063f874adcSsjur.brandeland@stericsson.com 10715c9ac0cSSjur Braendeland 10815c9ac0cSSjur Braendeland inline bool cfpkt_more(struct cfpkt *pkt) 10915c9ac0cSSjur Braendeland { 11015c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 11115c9ac0cSSjur Braendeland return skb->len > 0; 11215c9ac0cSSjur Braendeland } 1133f874adcSsjur.brandeland@stericsson.com 11415c9ac0cSSjur Braendeland 11515c9ac0cSSjur Braendeland int cfpkt_peek_head(struct cfpkt *pkt, void *data, u16 len) 11615c9ac0cSSjur Braendeland { 11715c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 11815c9ac0cSSjur Braendeland if (skb_headlen(skb) >= len) { 11915c9ac0cSSjur Braendeland memcpy(data, skb->data, len); 12015c9ac0cSSjur Braendeland return 0; 12115c9ac0cSSjur Braendeland } 12215c9ac0cSSjur Braendeland return !cfpkt_extr_head(pkt, data, len) && 12315c9ac0cSSjur Braendeland !cfpkt_add_head(pkt, data, len); 12415c9ac0cSSjur Braendeland } 12515c9ac0cSSjur Braendeland 12615c9ac0cSSjur Braendeland int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len) 12715c9ac0cSSjur Braendeland { 12815c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 12915c9ac0cSSjur Braendeland u8 *from; 13015c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 13115c9ac0cSSjur Braendeland return -EPROTO; 13215c9ac0cSSjur Braendeland 13315c9ac0cSSjur Braendeland if (unlikely(len > skb->len)) { 134b31fa5baSJoe Perches PKT_ERROR(pkt, "read beyond end of packet\n"); 13515c9ac0cSSjur Braendeland return -EPROTO; 13615c9ac0cSSjur Braendeland } 13715c9ac0cSSjur Braendeland 13815c9ac0cSSjur Braendeland if (unlikely(len > skb_headlen(skb))) { 13915c9ac0cSSjur Braendeland if (unlikely(skb_linearize(skb) != 0)) { 140b31fa5baSJoe Perches PKT_ERROR(pkt, "linearize failed\n"); 14115c9ac0cSSjur Braendeland return -EPROTO; 14215c9ac0cSSjur Braendeland } 14315c9ac0cSSjur Braendeland } 14415c9ac0cSSjur Braendeland from = skb_pull(skb, len); 14515c9ac0cSSjur Braendeland from -= len; 14615c9ac0cSSjur Braendeland memcpy(data, from, len); 14715c9ac0cSSjur Braendeland return 0; 14815c9ac0cSSjur Braendeland } 14915c9ac0cSSjur Braendeland 15015c9ac0cSSjur Braendeland int cfpkt_extr_trail(struct cfpkt *pkt, void *dta, u16 len) 15115c9ac0cSSjur Braendeland { 15215c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 15315c9ac0cSSjur Braendeland u8 *data = dta; 15415c9ac0cSSjur Braendeland u8 *from; 15515c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 15615c9ac0cSSjur Braendeland return -EPROTO; 15715c9ac0cSSjur Braendeland 15815c9ac0cSSjur Braendeland if (unlikely(skb_linearize(skb) != 0)) { 159b31fa5baSJoe Perches PKT_ERROR(pkt, "linearize failed\n"); 16015c9ac0cSSjur Braendeland return -EPROTO; 16115c9ac0cSSjur Braendeland } 16215c9ac0cSSjur Braendeland if (unlikely(skb->data + len > skb_tail_pointer(skb))) { 163b31fa5baSJoe Perches PKT_ERROR(pkt, "read beyond end of packet\n"); 16415c9ac0cSSjur Braendeland return -EPROTO; 16515c9ac0cSSjur Braendeland } 16615c9ac0cSSjur Braendeland from = skb_tail_pointer(skb) - len; 16715c9ac0cSSjur Braendeland skb_trim(skb, skb->len - len); 16815c9ac0cSSjur Braendeland memcpy(data, from, len); 16915c9ac0cSSjur Braendeland return 0; 17015c9ac0cSSjur Braendeland } 1713f874adcSsjur.brandeland@stericsson.com 17215c9ac0cSSjur Braendeland 17315c9ac0cSSjur Braendeland int cfpkt_pad_trail(struct cfpkt *pkt, u16 len) 17415c9ac0cSSjur Braendeland { 17515c9ac0cSSjur Braendeland return cfpkt_add_body(pkt, NULL, len); 17615c9ac0cSSjur Braendeland } 1773f874adcSsjur.brandeland@stericsson.com 17815c9ac0cSSjur Braendeland 17915c9ac0cSSjur Braendeland int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len) 18015c9ac0cSSjur Braendeland { 18115c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 18215c9ac0cSSjur Braendeland struct sk_buff *lastskb; 18315c9ac0cSSjur Braendeland u8 *to; 18415c9ac0cSSjur Braendeland u16 addlen = 0; 18515c9ac0cSSjur Braendeland 18615c9ac0cSSjur Braendeland 18715c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 18815c9ac0cSSjur Braendeland return -EPROTO; 18915c9ac0cSSjur Braendeland 19015c9ac0cSSjur Braendeland lastskb = skb; 19115c9ac0cSSjur Braendeland 19215c9ac0cSSjur Braendeland /* Check whether we need to add space at the tail */ 19315c9ac0cSSjur Braendeland if (unlikely(skb_tailroom(skb) < len)) { 19415c9ac0cSSjur Braendeland if (likely(len < PKT_LEN_WHEN_EXTENDING)) 19515c9ac0cSSjur Braendeland addlen = PKT_LEN_WHEN_EXTENDING; 19615c9ac0cSSjur Braendeland else 19715c9ac0cSSjur Braendeland addlen = len; 19815c9ac0cSSjur Braendeland } 19915c9ac0cSSjur Braendeland 20015c9ac0cSSjur Braendeland /* Check whether we need to change the SKB before writing to the tail */ 20115c9ac0cSSjur Braendeland if (unlikely((addlen > 0) || skb_cloned(skb) || skb_shared(skb))) { 20215c9ac0cSSjur Braendeland 20315c9ac0cSSjur Braendeland /* Make sure data is writable */ 20415c9ac0cSSjur Braendeland if (unlikely(skb_cow_data(skb, addlen, &lastskb) < 0)) { 205b31fa5baSJoe Perches PKT_ERROR(pkt, "cow failed\n"); 20615c9ac0cSSjur Braendeland return -EPROTO; 20715c9ac0cSSjur Braendeland } 20815c9ac0cSSjur Braendeland /* 20915c9ac0cSSjur Braendeland * Is the SKB non-linear after skb_cow_data()? If so, we are 21015c9ac0cSSjur Braendeland * going to add data to the last SKB, so we need to adjust 21115c9ac0cSSjur Braendeland * lengths of the top SKB. 21215c9ac0cSSjur Braendeland */ 21315c9ac0cSSjur Braendeland if (lastskb != skb) { 214b31fa5baSJoe Perches pr_warn("Packet is non-linear\n"); 21515c9ac0cSSjur Braendeland skb->len += len; 21615c9ac0cSSjur Braendeland skb->data_len += len; 21715c9ac0cSSjur Braendeland } 21815c9ac0cSSjur Braendeland } 21915c9ac0cSSjur Braendeland 22015c9ac0cSSjur Braendeland /* All set to put the last SKB and optionally write data there. */ 22115c9ac0cSSjur Braendeland to = skb_put(lastskb, len); 22215c9ac0cSSjur Braendeland if (likely(data)) 22315c9ac0cSSjur Braendeland memcpy(to, data, len); 22415c9ac0cSSjur Braendeland return 0; 22515c9ac0cSSjur Braendeland } 22615c9ac0cSSjur Braendeland 22715c9ac0cSSjur Braendeland inline int cfpkt_addbdy(struct cfpkt *pkt, u8 data) 22815c9ac0cSSjur Braendeland { 22915c9ac0cSSjur Braendeland return cfpkt_add_body(pkt, &data, 1); 23015c9ac0cSSjur Braendeland } 23115c9ac0cSSjur Braendeland 23215c9ac0cSSjur Braendeland int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len) 23315c9ac0cSSjur Braendeland { 23415c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 23515c9ac0cSSjur Braendeland struct sk_buff *lastskb; 23615c9ac0cSSjur Braendeland u8 *to; 23715c9ac0cSSjur Braendeland const u8 *data = data2; 238638e628aSSjur Braendeland int ret; 23915c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 24015c9ac0cSSjur Braendeland return -EPROTO; 24115c9ac0cSSjur Braendeland if (unlikely(skb_headroom(skb) < len)) { 242b31fa5baSJoe Perches PKT_ERROR(pkt, "no headroom\n"); 24315c9ac0cSSjur Braendeland return -EPROTO; 24415c9ac0cSSjur Braendeland } 24515c9ac0cSSjur Braendeland 24615c9ac0cSSjur Braendeland /* Make sure data is writable */ 247638e628aSSjur Braendeland ret = skb_cow_data(skb, 0, &lastskb); 248638e628aSSjur Braendeland if (unlikely(ret < 0)) { 249b31fa5baSJoe Perches PKT_ERROR(pkt, "cow failed\n"); 250638e628aSSjur Braendeland return ret; 25115c9ac0cSSjur Braendeland } 25215c9ac0cSSjur Braendeland 25315c9ac0cSSjur Braendeland to = skb_push(skb, len); 25415c9ac0cSSjur Braendeland memcpy(to, data, len); 25515c9ac0cSSjur Braendeland return 0; 25615c9ac0cSSjur Braendeland } 2573f874adcSsjur.brandeland@stericsson.com 25815c9ac0cSSjur Braendeland 25915c9ac0cSSjur Braendeland inline int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len) 26015c9ac0cSSjur Braendeland { 26115c9ac0cSSjur Braendeland return cfpkt_add_body(pkt, data, len); 26215c9ac0cSSjur Braendeland } 2633f874adcSsjur.brandeland@stericsson.com 26415c9ac0cSSjur Braendeland 26515c9ac0cSSjur Braendeland inline u16 cfpkt_getlen(struct cfpkt *pkt) 26615c9ac0cSSjur Braendeland { 26715c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 26815c9ac0cSSjur Braendeland return skb->len; 26915c9ac0cSSjur Braendeland } 2703f874adcSsjur.brandeland@stericsson.com 27115c9ac0cSSjur Braendeland 27215c9ac0cSSjur Braendeland inline u16 cfpkt_iterate(struct cfpkt *pkt, 27315c9ac0cSSjur Braendeland u16 (*iter_func)(u16, void *, u16), 27415c9ac0cSSjur Braendeland u16 data) 27515c9ac0cSSjur Braendeland { 27615c9ac0cSSjur Braendeland /* 27715c9ac0cSSjur Braendeland * Don't care about the performance hit of linearizing, 27815c9ac0cSSjur Braendeland * Checksum should not be used on high-speed interfaces anyway. 27915c9ac0cSSjur Braendeland */ 28015c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 28115c9ac0cSSjur Braendeland return -EPROTO; 28215c9ac0cSSjur Braendeland if (unlikely(skb_linearize(&pkt->skb) != 0)) { 283b31fa5baSJoe Perches PKT_ERROR(pkt, "linearize failed\n"); 28415c9ac0cSSjur Braendeland return -EPROTO; 28515c9ac0cSSjur Braendeland } 28615c9ac0cSSjur Braendeland return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt)); 28715c9ac0cSSjur Braendeland } 2883f874adcSsjur.brandeland@stericsson.com 28915c9ac0cSSjur Braendeland 29015c9ac0cSSjur Braendeland int cfpkt_setlen(struct cfpkt *pkt, u16 len) 29115c9ac0cSSjur Braendeland { 29215c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 29315c9ac0cSSjur Braendeland 29415c9ac0cSSjur Braendeland 29515c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 29615c9ac0cSSjur Braendeland return -EPROTO; 29715c9ac0cSSjur Braendeland 29815c9ac0cSSjur Braendeland if (likely(len <= skb->len)) { 29915c9ac0cSSjur Braendeland if (unlikely(skb->data_len)) 30015c9ac0cSSjur Braendeland ___pskb_trim(skb, len); 30115c9ac0cSSjur Braendeland else 30215c9ac0cSSjur Braendeland skb_trim(skb, len); 30315c9ac0cSSjur Braendeland 30415c9ac0cSSjur Braendeland return cfpkt_getlen(pkt); 30515c9ac0cSSjur Braendeland } 30615c9ac0cSSjur Braendeland 30715c9ac0cSSjur Braendeland /* Need to expand SKB */ 30815c9ac0cSSjur Braendeland if (unlikely(!cfpkt_pad_trail(pkt, len - skb->len))) 309b31fa5baSJoe Perches PKT_ERROR(pkt, "skb_pad_trail failed\n"); 31015c9ac0cSSjur Braendeland 31115c9ac0cSSjur Braendeland return cfpkt_getlen(pkt); 31215c9ac0cSSjur Braendeland } 31315c9ac0cSSjur Braendeland 31415c9ac0cSSjur Braendeland struct cfpkt *cfpkt_append(struct cfpkt *dstpkt, 31515c9ac0cSSjur Braendeland struct cfpkt *addpkt, 31615c9ac0cSSjur Braendeland u16 expectlen) 31715c9ac0cSSjur Braendeland { 31815c9ac0cSSjur Braendeland struct sk_buff *dst = pkt_to_skb(dstpkt); 31915c9ac0cSSjur Braendeland struct sk_buff *add = pkt_to_skb(addpkt); 32015c9ac0cSSjur Braendeland u16 addlen = skb_headlen(add); 32115c9ac0cSSjur Braendeland u16 neededtailspace; 32215c9ac0cSSjur Braendeland struct sk_buff *tmp; 32315c9ac0cSSjur Braendeland u16 dstlen; 32415c9ac0cSSjur Braendeland u16 createlen; 32515c9ac0cSSjur Braendeland if (unlikely(is_erronous(dstpkt) || is_erronous(addpkt))) { 32615c9ac0cSSjur Braendeland return dstpkt; 32715c9ac0cSSjur Braendeland } 32815c9ac0cSSjur Braendeland if (expectlen > addlen) 32915c9ac0cSSjur Braendeland neededtailspace = expectlen; 33015c9ac0cSSjur Braendeland else 33115c9ac0cSSjur Braendeland neededtailspace = addlen; 33215c9ac0cSSjur Braendeland 33315c9ac0cSSjur Braendeland if (dst->tail + neededtailspace > dst->end) { 33415c9ac0cSSjur Braendeland /* Create a dumplicate of 'dst' with more tail space */ 335638e628aSSjur Braendeland struct cfpkt *tmppkt; 33615c9ac0cSSjur Braendeland dstlen = skb_headlen(dst); 33715c9ac0cSSjur Braendeland createlen = dstlen + neededtailspace; 338638e628aSSjur Braendeland tmppkt = cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX); 339638e628aSSjur Braendeland if (tmppkt == NULL) 34015c9ac0cSSjur Braendeland return NULL; 341638e628aSSjur Braendeland tmp = pkt_to_skb(tmppkt); 34215c9ac0cSSjur Braendeland skb_set_tail_pointer(tmp, dstlen); 34315c9ac0cSSjur Braendeland tmp->len = dstlen; 34415c9ac0cSSjur Braendeland memcpy(tmp->data, dst->data, dstlen); 34515c9ac0cSSjur Braendeland cfpkt_destroy(dstpkt); 34615c9ac0cSSjur Braendeland dst = tmp; 34715c9ac0cSSjur Braendeland } 34815c9ac0cSSjur Braendeland memcpy(skb_tail_pointer(dst), add->data, skb_headlen(add)); 34915c9ac0cSSjur Braendeland cfpkt_destroy(addpkt); 35015c9ac0cSSjur Braendeland dst->tail += addlen; 35115c9ac0cSSjur Braendeland dst->len += addlen; 35215c9ac0cSSjur Braendeland return skb_to_pkt(dst); 35315c9ac0cSSjur Braendeland } 35415c9ac0cSSjur Braendeland 35515c9ac0cSSjur Braendeland struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos) 35615c9ac0cSSjur Braendeland { 35715c9ac0cSSjur Braendeland struct sk_buff *skb2; 35815c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 359638e628aSSjur Braendeland struct cfpkt *tmppkt; 36015c9ac0cSSjur Braendeland u8 *split = skb->data + pos; 36115c9ac0cSSjur Braendeland u16 len2nd = skb_tail_pointer(skb) - split; 36215c9ac0cSSjur Braendeland 36315c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 36415c9ac0cSSjur Braendeland return NULL; 36515c9ac0cSSjur Braendeland 36615c9ac0cSSjur Braendeland if (skb->data + pos > skb_tail_pointer(skb)) { 367b31fa5baSJoe Perches PKT_ERROR(pkt, "trying to split beyond end of packet\n"); 36815c9ac0cSSjur Braendeland return NULL; 36915c9ac0cSSjur Braendeland } 37015c9ac0cSSjur Braendeland 37115c9ac0cSSjur Braendeland /* Create a new packet for the second part of the data */ 372638e628aSSjur Braendeland tmppkt = cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX, 373638e628aSSjur Braendeland PKT_PREFIX); 374638e628aSSjur Braendeland if (tmppkt == NULL) 375638e628aSSjur Braendeland return NULL; 376638e628aSSjur Braendeland skb2 = pkt_to_skb(tmppkt); 377638e628aSSjur Braendeland 37815c9ac0cSSjur Braendeland 37915c9ac0cSSjur Braendeland if (skb2 == NULL) 38015c9ac0cSSjur Braendeland return NULL; 38115c9ac0cSSjur Braendeland 38215c9ac0cSSjur Braendeland /* Reduce the length of the original packet */ 38315c9ac0cSSjur Braendeland skb_set_tail_pointer(skb, pos); 38415c9ac0cSSjur Braendeland skb->len = pos; 38515c9ac0cSSjur Braendeland 38615c9ac0cSSjur Braendeland memcpy(skb2->data, split, len2nd); 38715c9ac0cSSjur Braendeland skb2->tail += len2nd; 38815c9ac0cSSjur Braendeland skb2->len += len2nd; 38915c9ac0cSSjur Braendeland return skb_to_pkt(skb2); 39015c9ac0cSSjur Braendeland } 39115c9ac0cSSjur Braendeland 39273d6ac63SStephen Hemminger bool cfpkt_erroneous(struct cfpkt *pkt) 39315c9ac0cSSjur Braendeland { 39415c9ac0cSSjur Braendeland return cfpkt_priv(pkt)->erronous; 39515c9ac0cSSjur Braendeland } 39615c9ac0cSSjur Braendeland 39715c9ac0cSSjur Braendeland struct caif_payload_info *cfpkt_info(struct cfpkt *pkt) 39815c9ac0cSSjur Braendeland { 39915c9ac0cSSjur Braendeland return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb; 40015c9ac0cSSjur Braendeland } 401