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 EXPORT_SYMBOL(cfpkt_create); 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 } 10715c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_destroy); 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 } 11415c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_more); 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 EXPORT_SYMBOL(cfpkt_peek_head); 12715c9ac0cSSjur Braendeland 12815c9ac0cSSjur Braendeland int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len) 12915c9ac0cSSjur Braendeland { 13015c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 13115c9ac0cSSjur Braendeland u8 *from; 13215c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 13315c9ac0cSSjur Braendeland return -EPROTO; 13415c9ac0cSSjur Braendeland 13515c9ac0cSSjur Braendeland if (unlikely(len > skb->len)) { 136b31fa5baSJoe Perches PKT_ERROR(pkt, "read beyond end of packet\n"); 13715c9ac0cSSjur Braendeland return -EPROTO; 13815c9ac0cSSjur Braendeland } 13915c9ac0cSSjur Braendeland 14015c9ac0cSSjur Braendeland if (unlikely(len > skb_headlen(skb))) { 14115c9ac0cSSjur Braendeland if (unlikely(skb_linearize(skb) != 0)) { 142b31fa5baSJoe Perches PKT_ERROR(pkt, "linearize failed\n"); 14315c9ac0cSSjur Braendeland return -EPROTO; 14415c9ac0cSSjur Braendeland } 14515c9ac0cSSjur Braendeland } 14615c9ac0cSSjur Braendeland from = skb_pull(skb, len); 14715c9ac0cSSjur Braendeland from -= len; 14815c9ac0cSSjur Braendeland memcpy(data, from, len); 14915c9ac0cSSjur Braendeland return 0; 15015c9ac0cSSjur Braendeland } 15115c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_extr_head); 15215c9ac0cSSjur Braendeland 15315c9ac0cSSjur Braendeland int cfpkt_extr_trail(struct cfpkt *pkt, void *dta, u16 len) 15415c9ac0cSSjur Braendeland { 15515c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 15615c9ac0cSSjur Braendeland u8 *data = dta; 15715c9ac0cSSjur Braendeland u8 *from; 15815c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 15915c9ac0cSSjur Braendeland return -EPROTO; 16015c9ac0cSSjur Braendeland 16115c9ac0cSSjur Braendeland if (unlikely(skb_linearize(skb) != 0)) { 162b31fa5baSJoe Perches PKT_ERROR(pkt, "linearize failed\n"); 16315c9ac0cSSjur Braendeland return -EPROTO; 16415c9ac0cSSjur Braendeland } 16515c9ac0cSSjur Braendeland if (unlikely(skb->data + len > skb_tail_pointer(skb))) { 166b31fa5baSJoe Perches PKT_ERROR(pkt, "read beyond end of packet\n"); 16715c9ac0cSSjur Braendeland return -EPROTO; 16815c9ac0cSSjur Braendeland } 16915c9ac0cSSjur Braendeland from = skb_tail_pointer(skb) - len; 17015c9ac0cSSjur Braendeland skb_trim(skb, skb->len - len); 17115c9ac0cSSjur Braendeland memcpy(data, from, len); 17215c9ac0cSSjur Braendeland return 0; 17315c9ac0cSSjur Braendeland } 17415c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_extr_trail); 17515c9ac0cSSjur Braendeland 17615c9ac0cSSjur Braendeland int cfpkt_pad_trail(struct cfpkt *pkt, u16 len) 17715c9ac0cSSjur Braendeland { 17815c9ac0cSSjur Braendeland return cfpkt_add_body(pkt, NULL, len); 17915c9ac0cSSjur Braendeland } 18015c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_pad_trail); 18115c9ac0cSSjur Braendeland 18215c9ac0cSSjur Braendeland int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len) 18315c9ac0cSSjur Braendeland { 18415c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 18515c9ac0cSSjur Braendeland struct sk_buff *lastskb; 18615c9ac0cSSjur Braendeland u8 *to; 18715c9ac0cSSjur Braendeland u16 addlen = 0; 18815c9ac0cSSjur Braendeland 18915c9ac0cSSjur Braendeland 19015c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 19115c9ac0cSSjur Braendeland return -EPROTO; 19215c9ac0cSSjur Braendeland 19315c9ac0cSSjur Braendeland lastskb = skb; 19415c9ac0cSSjur Braendeland 19515c9ac0cSSjur Braendeland /* Check whether we need to add space at the tail */ 19615c9ac0cSSjur Braendeland if (unlikely(skb_tailroom(skb) < len)) { 19715c9ac0cSSjur Braendeland if (likely(len < PKT_LEN_WHEN_EXTENDING)) 19815c9ac0cSSjur Braendeland addlen = PKT_LEN_WHEN_EXTENDING; 19915c9ac0cSSjur Braendeland else 20015c9ac0cSSjur Braendeland addlen = len; 20115c9ac0cSSjur Braendeland } 20215c9ac0cSSjur Braendeland 20315c9ac0cSSjur Braendeland /* Check whether we need to change the SKB before writing to the tail */ 20415c9ac0cSSjur Braendeland if (unlikely((addlen > 0) || skb_cloned(skb) || skb_shared(skb))) { 20515c9ac0cSSjur Braendeland 20615c9ac0cSSjur Braendeland /* Make sure data is writable */ 20715c9ac0cSSjur Braendeland if (unlikely(skb_cow_data(skb, addlen, &lastskb) < 0)) { 208b31fa5baSJoe Perches PKT_ERROR(pkt, "cow failed\n"); 20915c9ac0cSSjur Braendeland return -EPROTO; 21015c9ac0cSSjur Braendeland } 21115c9ac0cSSjur Braendeland /* 21215c9ac0cSSjur Braendeland * Is the SKB non-linear after skb_cow_data()? If so, we are 21315c9ac0cSSjur Braendeland * going to add data to the last SKB, so we need to adjust 21415c9ac0cSSjur Braendeland * lengths of the top SKB. 21515c9ac0cSSjur Braendeland */ 21615c9ac0cSSjur Braendeland if (lastskb != skb) { 217b31fa5baSJoe Perches pr_warn("Packet is non-linear\n"); 21815c9ac0cSSjur Braendeland skb->len += len; 21915c9ac0cSSjur Braendeland skb->data_len += len; 22015c9ac0cSSjur Braendeland } 22115c9ac0cSSjur Braendeland } 22215c9ac0cSSjur Braendeland 22315c9ac0cSSjur Braendeland /* All set to put the last SKB and optionally write data there. */ 22415c9ac0cSSjur Braendeland to = skb_put(lastskb, len); 22515c9ac0cSSjur Braendeland if (likely(data)) 22615c9ac0cSSjur Braendeland memcpy(to, data, len); 22715c9ac0cSSjur Braendeland return 0; 22815c9ac0cSSjur Braendeland } 22915c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_add_body); 23015c9ac0cSSjur Braendeland 23115c9ac0cSSjur Braendeland inline int cfpkt_addbdy(struct cfpkt *pkt, u8 data) 23215c9ac0cSSjur Braendeland { 23315c9ac0cSSjur Braendeland return cfpkt_add_body(pkt, &data, 1); 23415c9ac0cSSjur Braendeland } 23515c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_addbdy); 23615c9ac0cSSjur Braendeland 23715c9ac0cSSjur Braendeland int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len) 23815c9ac0cSSjur Braendeland { 23915c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 24015c9ac0cSSjur Braendeland struct sk_buff *lastskb; 24115c9ac0cSSjur Braendeland u8 *to; 24215c9ac0cSSjur Braendeland const u8 *data = data2; 243638e628aSSjur Braendeland int ret; 24415c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 24515c9ac0cSSjur Braendeland return -EPROTO; 24615c9ac0cSSjur Braendeland if (unlikely(skb_headroom(skb) < len)) { 247b31fa5baSJoe Perches PKT_ERROR(pkt, "no headroom\n"); 24815c9ac0cSSjur Braendeland return -EPROTO; 24915c9ac0cSSjur Braendeland } 25015c9ac0cSSjur Braendeland 25115c9ac0cSSjur Braendeland /* Make sure data is writable */ 252638e628aSSjur Braendeland ret = skb_cow_data(skb, 0, &lastskb); 253638e628aSSjur Braendeland if (unlikely(ret < 0)) { 254b31fa5baSJoe Perches PKT_ERROR(pkt, "cow failed\n"); 255638e628aSSjur Braendeland return ret; 25615c9ac0cSSjur Braendeland } 25715c9ac0cSSjur Braendeland 25815c9ac0cSSjur Braendeland to = skb_push(skb, len); 25915c9ac0cSSjur Braendeland memcpy(to, data, len); 26015c9ac0cSSjur Braendeland return 0; 26115c9ac0cSSjur Braendeland } 26215c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_add_head); 26315c9ac0cSSjur Braendeland 26415c9ac0cSSjur Braendeland inline int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len) 26515c9ac0cSSjur Braendeland { 26615c9ac0cSSjur Braendeland return cfpkt_add_body(pkt, data, len); 26715c9ac0cSSjur Braendeland } 26815c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_add_trail); 26915c9ac0cSSjur Braendeland 27015c9ac0cSSjur Braendeland inline u16 cfpkt_getlen(struct cfpkt *pkt) 27115c9ac0cSSjur Braendeland { 27215c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 27315c9ac0cSSjur Braendeland return skb->len; 27415c9ac0cSSjur Braendeland } 27515c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_getlen); 27615c9ac0cSSjur Braendeland 27715c9ac0cSSjur Braendeland inline u16 cfpkt_iterate(struct cfpkt *pkt, 27815c9ac0cSSjur Braendeland u16 (*iter_func)(u16, void *, u16), 27915c9ac0cSSjur Braendeland u16 data) 28015c9ac0cSSjur Braendeland { 28115c9ac0cSSjur Braendeland /* 28215c9ac0cSSjur Braendeland * Don't care about the performance hit of linearizing, 28315c9ac0cSSjur Braendeland * Checksum should not be used on high-speed interfaces anyway. 28415c9ac0cSSjur Braendeland */ 28515c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 28615c9ac0cSSjur Braendeland return -EPROTO; 28715c9ac0cSSjur Braendeland if (unlikely(skb_linearize(&pkt->skb) != 0)) { 288b31fa5baSJoe Perches PKT_ERROR(pkt, "linearize failed\n"); 28915c9ac0cSSjur Braendeland return -EPROTO; 29015c9ac0cSSjur Braendeland } 29115c9ac0cSSjur Braendeland return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt)); 29215c9ac0cSSjur Braendeland } 29315c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_iterate); 29415c9ac0cSSjur Braendeland 29515c9ac0cSSjur Braendeland int cfpkt_setlen(struct cfpkt *pkt, u16 len) 29615c9ac0cSSjur Braendeland { 29715c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 29815c9ac0cSSjur Braendeland 29915c9ac0cSSjur Braendeland 30015c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 30115c9ac0cSSjur Braendeland return -EPROTO; 30215c9ac0cSSjur Braendeland 30315c9ac0cSSjur Braendeland if (likely(len <= skb->len)) { 30415c9ac0cSSjur Braendeland if (unlikely(skb->data_len)) 30515c9ac0cSSjur Braendeland ___pskb_trim(skb, len); 30615c9ac0cSSjur Braendeland else 30715c9ac0cSSjur Braendeland skb_trim(skb, len); 30815c9ac0cSSjur Braendeland 30915c9ac0cSSjur Braendeland return cfpkt_getlen(pkt); 31015c9ac0cSSjur Braendeland } 31115c9ac0cSSjur Braendeland 31215c9ac0cSSjur Braendeland /* Need to expand SKB */ 31315c9ac0cSSjur Braendeland if (unlikely(!cfpkt_pad_trail(pkt, len - skb->len))) 314b31fa5baSJoe Perches PKT_ERROR(pkt, "skb_pad_trail failed\n"); 31515c9ac0cSSjur Braendeland 31615c9ac0cSSjur Braendeland return cfpkt_getlen(pkt); 31715c9ac0cSSjur Braendeland } 31815c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_setlen); 31915c9ac0cSSjur Braendeland 32015c9ac0cSSjur Braendeland struct cfpkt *cfpkt_append(struct cfpkt *dstpkt, 32115c9ac0cSSjur Braendeland struct cfpkt *addpkt, 32215c9ac0cSSjur Braendeland u16 expectlen) 32315c9ac0cSSjur Braendeland { 32415c9ac0cSSjur Braendeland struct sk_buff *dst = pkt_to_skb(dstpkt); 32515c9ac0cSSjur Braendeland struct sk_buff *add = pkt_to_skb(addpkt); 32615c9ac0cSSjur Braendeland u16 addlen = skb_headlen(add); 32715c9ac0cSSjur Braendeland u16 neededtailspace; 32815c9ac0cSSjur Braendeland struct sk_buff *tmp; 32915c9ac0cSSjur Braendeland u16 dstlen; 33015c9ac0cSSjur Braendeland u16 createlen; 33115c9ac0cSSjur Braendeland if (unlikely(is_erronous(dstpkt) || is_erronous(addpkt))) { 33215c9ac0cSSjur Braendeland return dstpkt; 33315c9ac0cSSjur Braendeland } 33415c9ac0cSSjur Braendeland if (expectlen > addlen) 33515c9ac0cSSjur Braendeland neededtailspace = expectlen; 33615c9ac0cSSjur Braendeland else 33715c9ac0cSSjur Braendeland neededtailspace = addlen; 33815c9ac0cSSjur Braendeland 33915c9ac0cSSjur Braendeland if (dst->tail + neededtailspace > dst->end) { 34015c9ac0cSSjur Braendeland /* Create a dumplicate of 'dst' with more tail space */ 341638e628aSSjur Braendeland struct cfpkt *tmppkt; 34215c9ac0cSSjur Braendeland dstlen = skb_headlen(dst); 34315c9ac0cSSjur Braendeland createlen = dstlen + neededtailspace; 344638e628aSSjur Braendeland tmppkt = cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX); 345638e628aSSjur Braendeland if (tmppkt == NULL) 34615c9ac0cSSjur Braendeland return NULL; 347638e628aSSjur Braendeland tmp = pkt_to_skb(tmppkt); 34815c9ac0cSSjur Braendeland skb_set_tail_pointer(tmp, dstlen); 34915c9ac0cSSjur Braendeland tmp->len = dstlen; 35015c9ac0cSSjur Braendeland memcpy(tmp->data, dst->data, dstlen); 35115c9ac0cSSjur Braendeland cfpkt_destroy(dstpkt); 35215c9ac0cSSjur Braendeland dst = tmp; 35315c9ac0cSSjur Braendeland } 35415c9ac0cSSjur Braendeland memcpy(skb_tail_pointer(dst), add->data, skb_headlen(add)); 35515c9ac0cSSjur Braendeland cfpkt_destroy(addpkt); 35615c9ac0cSSjur Braendeland dst->tail += addlen; 35715c9ac0cSSjur Braendeland dst->len += addlen; 35815c9ac0cSSjur Braendeland return skb_to_pkt(dst); 35915c9ac0cSSjur Braendeland } 36015c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_append); 36115c9ac0cSSjur Braendeland 36215c9ac0cSSjur Braendeland struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos) 36315c9ac0cSSjur Braendeland { 36415c9ac0cSSjur Braendeland struct sk_buff *skb2; 36515c9ac0cSSjur Braendeland struct sk_buff *skb = pkt_to_skb(pkt); 366638e628aSSjur Braendeland struct cfpkt *tmppkt; 36715c9ac0cSSjur Braendeland u8 *split = skb->data + pos; 36815c9ac0cSSjur Braendeland u16 len2nd = skb_tail_pointer(skb) - split; 36915c9ac0cSSjur Braendeland 37015c9ac0cSSjur Braendeland if (unlikely(is_erronous(pkt))) 37115c9ac0cSSjur Braendeland return NULL; 37215c9ac0cSSjur Braendeland 37315c9ac0cSSjur Braendeland if (skb->data + pos > skb_tail_pointer(skb)) { 374b31fa5baSJoe Perches PKT_ERROR(pkt, "trying to split beyond end of packet\n"); 37515c9ac0cSSjur Braendeland return NULL; 37615c9ac0cSSjur Braendeland } 37715c9ac0cSSjur Braendeland 37815c9ac0cSSjur Braendeland /* Create a new packet for the second part of the data */ 379638e628aSSjur Braendeland tmppkt = cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX, 380638e628aSSjur Braendeland PKT_PREFIX); 381638e628aSSjur Braendeland if (tmppkt == NULL) 382638e628aSSjur Braendeland return NULL; 383638e628aSSjur Braendeland skb2 = pkt_to_skb(tmppkt); 384638e628aSSjur Braendeland 38515c9ac0cSSjur Braendeland 38615c9ac0cSSjur Braendeland if (skb2 == NULL) 38715c9ac0cSSjur Braendeland return NULL; 38815c9ac0cSSjur Braendeland 38915c9ac0cSSjur Braendeland /* Reduce the length of the original packet */ 39015c9ac0cSSjur Braendeland skb_set_tail_pointer(skb, pos); 39115c9ac0cSSjur Braendeland skb->len = pos; 39215c9ac0cSSjur Braendeland 39315c9ac0cSSjur Braendeland memcpy(skb2->data, split, len2nd); 39415c9ac0cSSjur Braendeland skb2->tail += len2nd; 39515c9ac0cSSjur Braendeland skb2->len += len2nd; 39615c9ac0cSSjur Braendeland return skb_to_pkt(skb2); 39715c9ac0cSSjur Braendeland } 39815c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_split); 39915c9ac0cSSjur Braendeland 40073d6ac63SStephen Hemminger bool cfpkt_erroneous(struct cfpkt *pkt) 40115c9ac0cSSjur Braendeland { 40215c9ac0cSSjur Braendeland return cfpkt_priv(pkt)->erronous; 40315c9ac0cSSjur Braendeland } 40415c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_erroneous); 40515c9ac0cSSjur Braendeland 40615c9ac0cSSjur Braendeland 40715c9ac0cSSjur Braendeland struct caif_payload_info *cfpkt_info(struct cfpkt *pkt) 40815c9ac0cSSjur Braendeland { 40915c9ac0cSSjur Braendeland return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb; 41015c9ac0cSSjur Braendeland } 41115c9ac0cSSjur Braendeland EXPORT_SYMBOL(cfpkt_info); 412