static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, struct net_device *dev) { struct net *net = container_of(qp->q.net, struct net, ipv4.frags); struct iphdr *iph; struct sk_buff *fp, *head = qp->q.fragments; int len; int ihlen; int err; int sum_truesize; u8 ecn; ipq_kill(qp); ecn = ip_frag_ecn_table[qp->ecn]; if (unlikely(ecn == 0xff)) { err = -EINVAL; goto out_fail; } /* Make the one we just received the head. */ if (prev) { head = prev->next; fp = skb_clone(head, GFP_ATOMIC); if (!fp) goto out_nomem; fp->next = head->next; if (!fp->next) qp->q.fragments_tail = fp; prev->next = fp; skb_morph(head, qp->q.fragments); head->next = qp->q.fragments->next; consume_skb(qp->q.fragments); qp->q.fragments = head; } WARN_ON(head == NULL); WARN_ON(FRAG_CB(head)->offset != 0); /* Allocate a new buffer for the datagram. */ ihlen = ip_hdrlen(head); len = ihlen + qp->q.len; err = -E2BIG; if (len > 65535) goto out_oversize; /* Head of list must not be cloned. */ if (skb_unclone(head, GFP_ATOMIC)) goto out_nomem; /* If the first fragment is fragmented itself, we split * it to two chunks: the first with data and paged part * and the second, holding only fragments. */ if (skb_has_frag_list(head)) { struct sk_buff *clone; int i, plen = 0; if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) goto out_nomem; clone->next = head->next; head->next = clone; skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; skb_frag_list_init(head); for (i = 0; i < skb_shinfo(head)->nr_frags; i++) plen += skb_frag_size(&skb_shinfo(head)->frags[i]); clone->len = clone->data_len = head->data_len - plen; head->data_len -= clone->len; head->len -= clone->len; clone->csum = 0; clone->ip_summed = head->ip_summed; add_frag_mem_limit(&qp->q, clone->truesize); } skb_push(head, head->data - skb_network_header(head)); sum_truesize = head->truesize; for (fp = head->next; fp;) { bool headstolen; int delta; struct sk_buff *next = fp->next; sum_truesize += fp->truesize; if (head->ip_summed != fp->ip_summed) head->ip_summed = CHECKSUM_NONE; else if (head->ip_summed == CHECKSUM_COMPLETE) head->csum = csum_add(head->csum, fp->csum); if (skb_try_coalesce(head, fp, &headstolen, &delta)) { kfree_skb_partial(fp, headstolen); } else { if (!skb_shinfo(head)->frag_list) skb_shinfo(head)->frag_list = fp; head->data_len += fp->len; head->len += fp->len; head->truesize += fp->truesize; } fp = next; } sub_frag_mem_limit(&qp->q, sum_truesize); head->next = NULL; head->dev = dev; head->tstamp = qp->q.stamp; IPCB(head)->frag_max_size = qp->q.max_size; iph = ip_hdr(head); /* max_size != 0 implies at least one fragment had IP_DF set */ iph->frag_off = qp->q.max_size ? htons(IP_DF) : 0; iph->tot_len = htons(len); iph->tos |= ecn; ip_send_check(iph); IP_INC_STATS_BH(net, IPSTATS_MIB_REASMOKS); qp->q.fragments = NULL; qp->q.fragments_tail = NULL; return 0; out_nomem: LIMIT_NETDEBUG(KERN_ERR pr_fmt("queue_glue: no memory for gluing queue %p\n"), qp); err = -ENOMEM; goto out_fail; out_oversize: net_info_ratelimited("Oversized IP packet from %pI4\n", &qp->saddr); out_fail: IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS); return err; }
/* * Check if this packet is complete. * Returns NULL on failure by any reason, and pointer * to current nexthdr field in reassembled frame. * * It is called with locked fq, and caller must check that * queue is eligible for reassembly i.e. it is not COMPLETE, * the last and the first frames arrived and all the bits are here. */ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, struct net_device *dev) { struct net *net = container_of(fq->q.net, struct net, ipv6.frags); struct sk_buff *fp, *head = fq->q.fragments; int payload_len; unsigned int nhoff; int sum_truesize; u8 ecn; inet_frag_kill(&fq->q, &ip6_frags); ecn = ip_frag_ecn_table[fq->ecn]; if (unlikely(ecn == 0xff)) goto out_fail; /* Make the one we just received the head. */ if (prev) { head = prev->next; fp = skb_clone(head, GFP_ATOMIC); if (!fp) goto out_oom; fp->next = head->next; if (!fp->next) fq->q.fragments_tail = fp; prev->next = fp; skb_morph(head, fq->q.fragments); head->next = fq->q.fragments->next; consume_skb(fq->q.fragments); fq->q.fragments = head; } WARN_ON(head == NULL); WARN_ON(FRAG6_CB(head)->offset != 0); /* Unfragmented part is taken from the first segment. */ payload_len = ((head->data - skb_network_header(head)) - sizeof(struct ipv6hdr) + fq->q.len - sizeof(struct frag_hdr)); if (payload_len > IPV6_MAXPLEN) goto out_oversize; /* Head of list must not be cloned. */ if (skb_unclone(head, GFP_ATOMIC)) goto out_oom; /* If the first fragment is fragmented itself, we split * it to two chunks: the first with data and paged part * and the second, holding only fragments. */ if (skb_has_frag_list(head)) { struct sk_buff *clone; int i, plen = 0; clone = alloc_skb(0, GFP_ATOMIC); if (!clone) goto out_oom; clone->next = head->next; head->next = clone; skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; skb_frag_list_init(head); for (i = 0; i < skb_shinfo(head)->nr_frags; i++) plen += skb_frag_size(&skb_shinfo(head)->frags[i]); clone->len = clone->data_len = head->data_len - plen; head->data_len -= clone->len; head->len -= clone->len; clone->csum = 0; clone->ip_summed = head->ip_summed; add_frag_mem_limit(fq->q.net, clone->truesize); } /* We have to remove fragment header from datagram and to relocate * header in order to calculate ICV correctly. */ nhoff = fq->nhoffset; skb_network_header(head)[nhoff] = skb_transport_header(head)[0]; memmove(head->head + sizeof(struct frag_hdr), head->head, (head->data - head->head) - sizeof(struct frag_hdr)); if (skb_mac_header_was_set(head)) head->mac_header += sizeof(struct frag_hdr); head->network_header += sizeof(struct frag_hdr); skb_reset_transport_header(head); skb_push(head, head->data - skb_network_header(head)); sum_truesize = head->truesize; for (fp = head->next; fp;) { bool headstolen; int delta; struct sk_buff *next = fp->next; sum_truesize += fp->truesize; if (head->ip_summed != fp->ip_summed) head->ip_summed = CHECKSUM_NONE; else if (head->ip_summed == CHECKSUM_COMPLETE) head->csum = csum_add(head->csum, fp->csum); if (skb_try_coalesce(head, fp, &headstolen, &delta)) { kfree_skb_partial(fp, headstolen); } else { if (!skb_shinfo(head)->frag_list) skb_shinfo(head)->frag_list = fp; head->data_len += fp->len; head->len += fp->len; head->truesize += fp->truesize; } fp = next; } sub_frag_mem_limit(fq->q.net, sum_truesize); head->next = NULL; head->dev = dev; head->tstamp = fq->q.stamp; ipv6_hdr(head)->payload_len = htons(payload_len); ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn); IP6CB(head)->nhoff = nhoff; IP6CB(head)->flags |= IP6SKB_FRAGMENTED; IP6CB(head)->frag_max_size = fq->q.max_size; /* Yes, and fold redundant checksum back. 8) */ skb_postpush_rcsum(head, skb_network_header(head), skb_network_header_len(head)); rcu_read_lock(); __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS); rcu_read_unlock(); fq->q.fragments = NULL; fq->q.fragments_tail = NULL; return 1; out_oversize: net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len); goto out_fail; out_oom: net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n"); out_fail: rcu_read_lock(); __IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS); rcu_read_unlock(); return -1; }
/* Check if this packet is complete. * Returns NULL on failure by any reason, and pointer * to current nexthdr field in reassembled frame. * * It is called with locked fq, and caller must check that * queue is eligible for reassembly i.e. it is not COMPLETE, * the last and the first frames arrived and all the bits are here. */ static int lowpan_frag_reasm(struct lowpan_frag_queue *fq, struct sk_buff *prev, struct net_device *dev) { struct sk_buff *fp, *head = fq->q.fragments; int sum_truesize; inet_frag_kill(&fq->q, &lowpan_frags); /* Make the one we just received the head. */ if (prev) { head = prev->next; fp = skb_clone(head, GFP_ATOMIC); if (!fp) goto out_oom; fp->next = head->next; if (!fp->next) fq->q.fragments_tail = fp; prev->next = fp; skb_morph(head, fq->q.fragments); head->next = fq->q.fragments->next; consume_skb(fq->q.fragments); fq->q.fragments = head; } /* Head of list must not be cloned. */ if (skb_unclone(head, GFP_ATOMIC)) goto out_oom; /* If the first fragment is fragmented itself, we split * it to two chunks: the first with data and paged part * and the second, holding only fragments. */ if (skb_has_frag_list(head)) { struct sk_buff *clone; int i, plen = 0; clone = alloc_skb(0, GFP_ATOMIC); if (!clone) goto out_oom; clone->next = head->next; head->next = clone; skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; skb_frag_list_init(head); for (i = 0; i < skb_shinfo(head)->nr_frags; i++) plen += skb_frag_size(&skb_shinfo(head)->frags[i]); clone->len = head->data_len - plen; clone->data_len = clone->len; head->data_len -= clone->len; head->len -= clone->len; add_frag_mem_limit(&fq->q, clone->truesize); } WARN_ON(head == NULL); sum_truesize = head->truesize; for (fp = head->next; fp;) { bool headstolen; int delta; struct sk_buff *next = fp->next; sum_truesize += fp->truesize; if (skb_try_coalesce(head, fp, &headstolen, &delta)) { kfree_skb_partial(fp, headstolen); } else { if (!skb_shinfo(head)->frag_list) skb_shinfo(head)->frag_list = fp; head->data_len += fp->len; head->len += fp->len; head->truesize += fp->truesize; } fp = next; } sub_frag_mem_limit(&fq->q, sum_truesize); head->next = NULL; head->dev = dev; head->tstamp = fq->q.stamp; fq->q.fragments = NULL; fq->q.fragments_tail = NULL; return 1; out_oom: net_dbg_ratelimited("lowpan_frag_reasm: no memory for reassembly\n"); return -1; }
/* tipc_buf_append(): Append a buffer to the fragment list of another buffer * @*headbuf: in: NULL for first frag, otherwise value returned from prev call * out: set when successful non-complete reassembly, otherwise NULL * @*buf: in: the buffer to append. Always defined * out: head buf after successful complete reassembly, otherwise NULL * Returns 1 when reassembly complete, otherwise 0 */ int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf) { struct sk_buff *head = *headbuf; struct sk_buff *frag = *buf; struct sk_buff *tail; struct tipc_msg *msg; u32 fragid; int delta; bool headstolen; if (!frag) goto err; msg = buf_msg(frag); fragid = msg_type(msg); frag->next = NULL; skb_pull(frag, msg_hdr_sz(msg)); if (fragid == FIRST_FRAGMENT) { if (unlikely(head)) goto err; if (unlikely(skb_unclone(frag, GFP_ATOMIC))) goto err; head = *headbuf = frag; skb_frag_list_init(head); TIPC_SKB_CB(head)->tail = NULL; *buf = NULL; return 0; } if (!head) goto err; if (skb_try_coalesce(head, frag, &headstolen, &delta)) { kfree_skb_partial(frag, headstolen); } else { tail = TIPC_SKB_CB(head)->tail; if (!skb_has_frag_list(head)) skb_shinfo(head)->frag_list = frag; else tail->next = frag; head->truesize += frag->truesize; head->data_len += frag->len; head->len += frag->len; TIPC_SKB_CB(head)->tail = frag; } if (fragid == LAST_FRAGMENT) { *buf = head; TIPC_SKB_CB(head)->tail = NULL; *headbuf = NULL; return 1; } *buf = NULL; return 0; err: pr_warn_ratelimited("Unable to build fragment list\n"); kfree_skb(*buf); kfree_skb(*headbuf); *buf = *headbuf = NULL; return 0; }