diff options
Diffstat (limited to 'kernel/net/ipv4/ip_fragment.c')
-rw-r--r-- | kernel/net/ipv4/ip_fragment.c | 120 |
1 files changed, 74 insertions, 46 deletions
diff --git a/kernel/net/ipv4/ip_fragment.c b/kernel/net/ipv4/ip_fragment.c index cae22a1a8..b8a0607da 100644 --- a/kernel/net/ipv4/ip_fragment.c +++ b/kernel/net/ipv4/ip_fragment.c @@ -48,6 +48,7 @@ #include <linux/inet.h> #include <linux/netfilter_ipv4.h> #include <net/inet_ecn.h> +#include <net/l3mdev.h> /* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6 * code now. If you change something here, _PLEASE_ update ipv6/reassembly.c @@ -75,7 +76,9 @@ struct ipq { __be16 id; u8 protocol; u8 ecn; /* RFC3168 support */ + u16 max_df_size; /* largest frag with DF set seen */ int iif; + int vif; /* L3 master device index */ unsigned int rid; struct inet_peer *peer; }; @@ -98,6 +101,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, struct ip4_create_arg { struct iphdr *iph; u32 user; + int vif; }; static unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot) @@ -126,7 +130,8 @@ static bool ip4_frag_match(const struct inet_frag_queue *q, const void *a) qp->saddr == arg->iph->saddr && qp->daddr == arg->iph->daddr && qp->protocol == arg->iph->protocol && - qp->user == arg->user; + qp->user == arg->user && + qp->vif == arg->vif; } static void ip4_frag_init(struct inet_frag_queue *q, const void *a) @@ -143,9 +148,11 @@ static void ip4_frag_init(struct inet_frag_queue *q, const void *a) qp->ecn = ip4_frag_ecn(arg->iph->tos); qp->saddr = arg->iph->saddr; qp->daddr = arg->iph->daddr; + qp->vif = arg->vif; qp->user = arg->user; qp->peer = sysctl_ipfrag_max_dist ? - inet_getpeer_v4(net->ipv4.peers, arg->iph->saddr, 1) : NULL; + inet_getpeer_v4(net->ipv4.peers, arg->iph->saddr, arg->vif, 1) : + NULL; } static void ip4_frag_free(struct inet_frag_queue *q) @@ -173,6 +180,15 @@ static void ipq_kill(struct ipq *ipq) inet_frag_kill(&ipq->q, &ip4_frags); } +static bool frag_expire_skip_icmp(u32 user) +{ + return user == IP_DEFRAG_AF_PACKET || + ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_IN, + __IP_DEFRAG_CONNTRACK_IN_END) || + ip_defrag_user_in_between(user, IP_DEFRAG_CONNTRACK_BRIDGE_IN, + __IP_DEFRAG_CONNTRACK_BRIDGE_IN); +} + /* * Oops, a fragment queue timed out. Kill it and send an ICMP reply. */ @@ -192,7 +208,7 @@ static void ip_expire(unsigned long arg) ipq_kill(qp); IP_INC_STATS_BH(net, IPSTATS_MIB_REASMFAILS); - if (!(qp->q.flags & INET_FRAG_EVICTED)) { + if (!inet_frag_evicting(&qp->q)) { struct sk_buff *head = qp->q.fragments; const struct iphdr *iph; int err; @@ -217,10 +233,8 @@ static void ip_expire(unsigned long arg) /* Only an end host needs to send an ICMP * "Fragment Reassembly Timeout" message, per RFC792. */ - if (qp->user == IP_DEFRAG_AF_PACKET || - ((qp->user >= IP_DEFRAG_CONNTRACK_IN) && - (qp->user <= __IP_DEFRAG_CONNTRACK_IN_END) && - (skb_rtable(head)->rt_type != RTN_LOCAL))) + if (frag_expire_skip_icmp(qp->user) && + (skb_rtable(head)->rt_type != RTN_LOCAL)) goto out_rcu_unlock; /* Send an ICMP "Fragment Reassembly Timeout" message. */ @@ -236,7 +250,8 @@ out: /* Find the correct entry in the "incomplete datagrams" queue for * this IP datagram, and create new one, if nothing is found. */ -static struct ipq *ip_find(struct net *net, struct iphdr *iph, u32 user) +static struct ipq *ip_find(struct net *net, struct iphdr *iph, + u32 user, int vif) { struct inet_frag_queue *q; struct ip4_create_arg arg; @@ -244,6 +259,7 @@ static struct ipq *ip_find(struct net *net, struct iphdr *iph, u32 user) arg.iph = iph; arg.user = user; + arg.vif = vif; hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol); @@ -301,7 +317,7 @@ static int ip_frag_reinit(struct ipq *qp) kfree_skb(fp); fp = xp; } while (fp); - sub_frag_mem_limit(&qp->q, sum_truesize); + sub_frag_mem_limit(qp->q.net, sum_truesize); qp->q.flags = 0; qp->q.len = 0; @@ -319,6 +335,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) { struct sk_buff *prev, *next; struct net_device *dev; + unsigned int fragsize; int flags, offset; int ihl, end; int err = -ENOENT; @@ -446,7 +463,7 @@ found: qp->q.fragments = next; qp->q.meat -= free_it->len; - sub_frag_mem_limit(&qp->q, free_it->truesize); + sub_frag_mem_limit(qp->q.net, free_it->truesize); kfree_skb(free_it); } } @@ -470,13 +487,18 @@ found: qp->q.stamp = skb->tstamp; qp->q.meat += skb->len; qp->ecn |= ecn; - add_frag_mem_limit(&qp->q, skb->truesize); + add_frag_mem_limit(qp->q.net, skb->truesize); if (offset == 0) qp->q.flags |= INET_FRAG_FIRST_IN; + fragsize = skb->len + ihl; + + if (fragsize > qp->q.max_size) + qp->q.max_size = fragsize; + if (ip_hdr(skb)->frag_off & htons(IP_DF) && - skb->len + ihl > qp->q.max_size) - qp->q.max_size = skb->len + ihl; + fragsize > qp->max_df_size) + qp->max_df_size = fragsize; if (qp->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && qp->q.meat == qp->q.len) { @@ -508,7 +530,6 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, int len; int ihlen; int err; - int sum_truesize; u8 ecn; ipq_kill(qp); @@ -573,47 +594,47 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, head->len -= clone->len; clone->csum = 0; clone->ip_summed = head->ip_summed; - add_frag_mem_limit(&qp->q, clone->truesize); + add_frag_mem_limit(qp->q.net, clone->truesize); } + skb_shinfo(head)->frag_list = head->next; 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; + for (fp=head->next; fp; fp = fp->next) { + head->data_len += fp->len; + head->len += fp->len; 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; + head->truesize += fp->truesize; } - sub_frag_mem_limit(&qp->q, sum_truesize); + sub_frag_mem_limit(qp->q.net, head->truesize); head->next = NULL; head->dev = dev; head->tstamp = qp->q.stamp; - IPCB(head)->frag_max_size = qp->q.max_size; + IPCB(head)->frag_max_size = max(qp->max_df_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; + /* When we set IP_DF on a refragmented skb we must also force a + * call to ip_fragment to avoid forwarding a DF-skb of size s while + * original sender only sent fragments of size f (where f < s). + * + * We only set DF/IPSKB_FRAG_PMTU if such DF fragment was the largest + * frag seen to avoid sending tiny DF-fragments in case skb was built + * from one very small df-fragment and one large non-df frag. + */ + if (qp->max_df_size == qp->q.max_size) { + IPCB(head)->flags |= IPSKB_FRAG_PMTU; + iph->frag_off = htons(IP_DF); + } else { + iph->frag_off = 0; + } + ip_send_check(iph); IP_INC_STATS_BH(net, IPSTATS_MIB_REASMOKS); @@ -633,16 +654,17 @@ out_fail: } /* Process an incoming IP datagram fragment. */ -int ip_defrag(struct sk_buff *skb, u32 user) +int ip_defrag(struct net *net, struct sk_buff *skb, u32 user) { + struct net_device *dev = skb->dev ? : skb_dst(skb)->dev; + int vif = l3mdev_master_ifindex_rcu(dev); struct ipq *qp; - struct net *net; - net = skb->dev ? dev_net(skb->dev) : dev_net(skb_dst(skb)->dev); IP_INC_STATS_BH(net, IPSTATS_MIB_REASMREQDS); + skb_orphan(skb); /* Lookup (or create) queue header */ - qp = ip_find(net, ip_hdr(skb), user); + qp = ip_find(net, ip_hdr(skb), user, vif); if (qp) { int ret; @@ -661,7 +683,7 @@ int ip_defrag(struct sk_buff *skb, u32 user) } EXPORT_SYMBOL(ip_defrag); -struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user) +struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user) { struct iphdr iph; int netoff; @@ -690,7 +712,7 @@ struct sk_buff *ip_check_defrag(struct sk_buff *skb, u32 user) if (pskb_trim_rcsum(skb, netoff + len)) return skb; memset(IPCB(skb), 0, sizeof(struct inet_skb_parm)); - if (ip_defrag(skb, user)) + if (ip_defrag(net, skb, user)) return NULL; skb_clear_hash(skb); } @@ -818,6 +840,8 @@ static void __init ip4_frags_ctl_register(void) static int __net_init ipv4_frags_init_net(struct net *net) { + int res; + /* Fragment cache limits. * * The fragment memory accounting code, (tries to) account for @@ -841,9 +865,13 @@ static int __net_init ipv4_frags_init_net(struct net *net) */ net->ipv4.frags.timeout = IP_FRAG_TIME; - inet_frags_init_net(&net->ipv4.frags); - - return ip4_frags_ns_ctl_register(net); + res = inet_frags_init_net(&net->ipv4.frags); + if (res) + return res; + res = ip4_frags_ns_ctl_register(net); + if (res) + inet_frags_uninit_net(&net->ipv4.frags); + return res; } static void __net_exit ipv4_frags_exit_net(struct net *net) |