From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- net/caif/cfpkt_skbuff.c | 393 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 393 insertions(+) create mode 100644 net/caif/cfpkt_skbuff.c (limited to 'net/caif/cfpkt_skbuff.c') diff --git a/net/caif/cfpkt_skbuff.c b/net/caif/cfpkt_skbuff.c new file mode 100644 index 000000000..f6c3b2137 --- /dev/null +++ b/net/caif/cfpkt_skbuff.c @@ -0,0 +1,393 @@ +/* + * Copyright (C) ST-Ericsson AB 2010 + * Author: Sjur Brendeland + * License terms: GNU General Public License (GPL) version 2 + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__ + +#include +#include +#include +#include +#include + +#define PKT_PREFIX 48 +#define PKT_POSTFIX 2 +#define PKT_LEN_WHEN_EXTENDING 128 +#define PKT_ERROR(pkt, errmsg) \ +do { \ + cfpkt_priv(pkt)->erronous = true; \ + skb_reset_tail_pointer(&pkt->skb); \ + pr_warn(errmsg); \ +} while (0) + +struct cfpktq { + struct sk_buff_head head; + atomic_t count; + /* Lock protects count updates */ + spinlock_t lock; +}; + +/* + * net/caif/ is generic and does not + * understand SKB, so we do this typecast + */ +struct cfpkt { + struct sk_buff skb; +}; + +/* Private data inside SKB */ +struct cfpkt_priv_data { + struct dev_info dev_info; + bool erronous; +}; + +static inline struct cfpkt_priv_data *cfpkt_priv(struct cfpkt *pkt) +{ + return (struct cfpkt_priv_data *) pkt->skb.cb; +} + +static inline bool is_erronous(struct cfpkt *pkt) +{ + return cfpkt_priv(pkt)->erronous; +} + +static inline struct sk_buff *pkt_to_skb(struct cfpkt *pkt) +{ + return &pkt->skb; +} + +static inline struct cfpkt *skb_to_pkt(struct sk_buff *skb) +{ + return (struct cfpkt *) skb; +} + +struct cfpkt *cfpkt_fromnative(enum caif_direction dir, void *nativepkt) +{ + struct cfpkt *pkt = skb_to_pkt(nativepkt); + cfpkt_priv(pkt)->erronous = false; + return pkt; +} +EXPORT_SYMBOL(cfpkt_fromnative); + +void *cfpkt_tonative(struct cfpkt *pkt) +{ + return (void *) pkt; +} +EXPORT_SYMBOL(cfpkt_tonative); + +static struct cfpkt *cfpkt_create_pfx(u16 len, u16 pfx) +{ + struct sk_buff *skb; + + if (likely(in_interrupt())) + skb = alloc_skb(len + pfx, GFP_ATOMIC); + else + skb = alloc_skb(len + pfx, GFP_KERNEL); + + if (unlikely(skb == NULL)) + return NULL; + + skb_reserve(skb, pfx); + return skb_to_pkt(skb); +} + +inline struct cfpkt *cfpkt_create(u16 len) +{ + return cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX); +} + +void cfpkt_destroy(struct cfpkt *pkt) +{ + struct sk_buff *skb = pkt_to_skb(pkt); + kfree_skb(skb); +} + +inline bool cfpkt_more(struct cfpkt *pkt) +{ + struct sk_buff *skb = pkt_to_skb(pkt); + return skb->len > 0; +} + +int cfpkt_peek_head(struct cfpkt *pkt, void *data, u16 len) +{ + struct sk_buff *skb = pkt_to_skb(pkt); + if (skb_headlen(skb) >= len) { + memcpy(data, skb->data, len); + return 0; + } + return !cfpkt_extr_head(pkt, data, len) && + !cfpkt_add_head(pkt, data, len); +} + +int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len) +{ + struct sk_buff *skb = pkt_to_skb(pkt); + u8 *from; + if (unlikely(is_erronous(pkt))) + return -EPROTO; + + if (unlikely(len > skb->len)) { + PKT_ERROR(pkt, "read beyond end of packet\n"); + return -EPROTO; + } + + if (unlikely(len > skb_headlen(skb))) { + if (unlikely(skb_linearize(skb) != 0)) { + PKT_ERROR(pkt, "linearize failed\n"); + return -EPROTO; + } + } + from = skb_pull(skb, len); + from -= len; + if (data) + memcpy(data, from, len); + return 0; +} +EXPORT_SYMBOL(cfpkt_extr_head); + +int cfpkt_extr_trail(struct cfpkt *pkt, void *dta, u16 len) +{ + struct sk_buff *skb = pkt_to_skb(pkt); + u8 *data = dta; + u8 *from; + if (unlikely(is_erronous(pkt))) + return -EPROTO; + + if (unlikely(skb_linearize(skb) != 0)) { + PKT_ERROR(pkt, "linearize failed\n"); + return -EPROTO; + } + if (unlikely(skb->data + len > skb_tail_pointer(skb))) { + PKT_ERROR(pkt, "read beyond end of packet\n"); + return -EPROTO; + } + from = skb_tail_pointer(skb) - len; + skb_trim(skb, skb->len - len); + memcpy(data, from, len); + return 0; +} + +int cfpkt_pad_trail(struct cfpkt *pkt, u16 len) +{ + return cfpkt_add_body(pkt, NULL, len); +} + +int cfpkt_add_body(struct cfpkt *pkt, const void *data, u16 len) +{ + struct sk_buff *skb = pkt_to_skb(pkt); + struct sk_buff *lastskb; + u8 *to; + u16 addlen = 0; + + + if (unlikely(is_erronous(pkt))) + return -EPROTO; + + lastskb = skb; + + /* Check whether we need to add space at the tail */ + if (unlikely(skb_tailroom(skb) < len)) { + if (likely(len < PKT_LEN_WHEN_EXTENDING)) + addlen = PKT_LEN_WHEN_EXTENDING; + else + addlen = len; + } + + /* Check whether we need to change the SKB before writing to the tail */ + if (unlikely((addlen > 0) || skb_cloned(skb) || skb_shared(skb))) { + + /* Make sure data is writable */ + if (unlikely(skb_cow_data(skb, addlen, &lastskb) < 0)) { + PKT_ERROR(pkt, "cow failed\n"); + return -EPROTO; + } + } + + /* All set to put the last SKB and optionally write data there. */ + to = pskb_put(skb, lastskb, len); + if (likely(data)) + memcpy(to, data, len); + return 0; +} + +inline int cfpkt_addbdy(struct cfpkt *pkt, u8 data) +{ + return cfpkt_add_body(pkt, &data, 1); +} + +int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len) +{ + struct sk_buff *skb = pkt_to_skb(pkt); + struct sk_buff *lastskb; + u8 *to; + const u8 *data = data2; + int ret; + if (unlikely(is_erronous(pkt))) + return -EPROTO; + if (unlikely(skb_headroom(skb) < len)) { + PKT_ERROR(pkt, "no headroom\n"); + return -EPROTO; + } + + /* Make sure data is writable */ + ret = skb_cow_data(skb, 0, &lastskb); + if (unlikely(ret < 0)) { + PKT_ERROR(pkt, "cow failed\n"); + return ret; + } + + to = skb_push(skb, len); + memcpy(to, data, len); + return 0; +} +EXPORT_SYMBOL(cfpkt_add_head); + +inline int cfpkt_add_trail(struct cfpkt *pkt, const void *data, u16 len) +{ + return cfpkt_add_body(pkt, data, len); +} + +inline u16 cfpkt_getlen(struct cfpkt *pkt) +{ + struct sk_buff *skb = pkt_to_skb(pkt); + return skb->len; +} + +int cfpkt_iterate(struct cfpkt *pkt, + u16 (*iter_func)(u16, void *, u16), + u16 data) +{ + /* + * Don't care about the performance hit of linearizing, + * Checksum should not be used on high-speed interfaces anyway. + */ + if (unlikely(is_erronous(pkt))) + return -EPROTO; + if (unlikely(skb_linearize(&pkt->skb) != 0)) { + PKT_ERROR(pkt, "linearize failed\n"); + return -EPROTO; + } + return iter_func(data, pkt->skb.data, cfpkt_getlen(pkt)); +} + +int cfpkt_setlen(struct cfpkt *pkt, u16 len) +{ + struct sk_buff *skb = pkt_to_skb(pkt); + + + if (unlikely(is_erronous(pkt))) + return -EPROTO; + + if (likely(len <= skb->len)) { + if (unlikely(skb->data_len)) + ___pskb_trim(skb, len); + else + skb_trim(skb, len); + + return cfpkt_getlen(pkt); + } + + /* Need to expand SKB */ + if (unlikely(!cfpkt_pad_trail(pkt, len - skb->len))) + PKT_ERROR(pkt, "skb_pad_trail failed\n"); + + return cfpkt_getlen(pkt); +} + +struct cfpkt *cfpkt_append(struct cfpkt *dstpkt, + struct cfpkt *addpkt, + u16 expectlen) +{ + struct sk_buff *dst = pkt_to_skb(dstpkt); + struct sk_buff *add = pkt_to_skb(addpkt); + u16 addlen = skb_headlen(add); + u16 neededtailspace; + struct sk_buff *tmp; + u16 dstlen; + u16 createlen; + if (unlikely(is_erronous(dstpkt) || is_erronous(addpkt))) { + return dstpkt; + } + if (expectlen > addlen) + neededtailspace = expectlen; + else + neededtailspace = addlen; + + if (dst->tail + neededtailspace > dst->end) { + /* Create a dumplicate of 'dst' with more tail space */ + struct cfpkt *tmppkt; + dstlen = skb_headlen(dst); + createlen = dstlen + neededtailspace; + tmppkt = cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX); + if (tmppkt == NULL) + return NULL; + tmp = pkt_to_skb(tmppkt); + skb_set_tail_pointer(tmp, dstlen); + tmp->len = dstlen; + memcpy(tmp->data, dst->data, dstlen); + cfpkt_destroy(dstpkt); + dst = tmp; + } + memcpy(skb_tail_pointer(dst), add->data, skb_headlen(add)); + cfpkt_destroy(addpkt); + dst->tail += addlen; + dst->len += addlen; + return skb_to_pkt(dst); +} + +struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos) +{ + struct sk_buff *skb2; + struct sk_buff *skb = pkt_to_skb(pkt); + struct cfpkt *tmppkt; + u8 *split = skb->data + pos; + u16 len2nd = skb_tail_pointer(skb) - split; + + if (unlikely(is_erronous(pkt))) + return NULL; + + if (skb->data + pos > skb_tail_pointer(skb)) { + PKT_ERROR(pkt, "trying to split beyond end of packet\n"); + return NULL; + } + + /* Create a new packet for the second part of the data */ + tmppkt = cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX, + PKT_PREFIX); + if (tmppkt == NULL) + return NULL; + skb2 = pkt_to_skb(tmppkt); + + + if (skb2 == NULL) + return NULL; + + /* Reduce the length of the original packet */ + skb_set_tail_pointer(skb, pos); + skb->len = pos; + + memcpy(skb2->data, split, len2nd); + skb2->tail += len2nd; + skb2->len += len2nd; + skb2->priority = skb->priority; + return skb_to_pkt(skb2); +} + +bool cfpkt_erroneous(struct cfpkt *pkt) +{ + return cfpkt_priv(pkt)->erronous; +} + +struct caif_payload_info *cfpkt_info(struct cfpkt *pkt) +{ + return (struct caif_payload_info *)&pkt_to_skb(pkt)->cb; +} +EXPORT_SYMBOL(cfpkt_info); + +void cfpkt_set_prio(struct cfpkt *pkt, int prio) +{ + pkt_to_skb(pkt)->priority = prio; +} +EXPORT_SYMBOL(cfpkt_set_prio); -- cgit v1.2.3-54-g00ecf