11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * INET An implementation of the TCP/IP protocol suite for the LINUX 31da177e4SLinus Torvalds * operating system. INET is implemented using the BSD Socket 41da177e4SLinus Torvalds * interface as the means of communication with the user level. 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * The Internet Protocol (IP) output module. 71da177e4SLinus Torvalds * 802c30a84SJesper Juhl * Authors: Ross Biro 91da177e4SLinus Torvalds * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> 101da177e4SLinus Torvalds * Donald Becker, <becker@super.org> 111da177e4SLinus Torvalds * Alan Cox, <Alan.Cox@linux.org> 121da177e4SLinus Torvalds * Richard Underwood 131da177e4SLinus Torvalds * Stefan Becker, <stefanb@yello.ping.de> 141da177e4SLinus Torvalds * Jorge Cwik, <jorge@laser.satlink.net> 151da177e4SLinus Torvalds * Arnt Gulbrandsen, <agulbra@nvg.unit.no> 161da177e4SLinus Torvalds * Hirokazu Takahashi, <taka@valinux.co.jp> 171da177e4SLinus Torvalds * 181da177e4SLinus Torvalds * See ip_input.c for original log 191da177e4SLinus Torvalds * 201da177e4SLinus Torvalds * Fixes: 211da177e4SLinus Torvalds * Alan Cox : Missing nonblock feature in ip_build_xmit. 221da177e4SLinus Torvalds * Mike Kilburn : htons() missing in ip_build_xmit. 231da177e4SLinus Torvalds * Bradford Johnson: Fix faulty handling of some frames when 241da177e4SLinus Torvalds * no route is found. 251da177e4SLinus Torvalds * Alexander Demenshin: Missing sk/skb free in ip_queue_xmit 261da177e4SLinus Torvalds * (in case if packet not accepted by 271da177e4SLinus Torvalds * output firewall rules) 281da177e4SLinus Torvalds * Mike McLagan : Routing by source 291da177e4SLinus Torvalds * Alexey Kuznetsov: use new route cache 301da177e4SLinus Torvalds * Andi Kleen: Fix broken PMTU recovery and remove 311da177e4SLinus Torvalds * some redundant tests. 321da177e4SLinus Torvalds * Vitaly E. Lavrov : Transparent proxy revived after year coma. 331da177e4SLinus Torvalds * Andi Kleen : Replace ip_reply with ip_send_reply. 341da177e4SLinus Torvalds * Andi Kleen : Split fast and slow ip_build_xmit path 351da177e4SLinus Torvalds * for decreased register pressure on x86 361da177e4SLinus Torvalds * and more readibility. 371da177e4SLinus Torvalds * Marc Boucher : When call_out_firewall returns FW_QUEUE, 381da177e4SLinus Torvalds * silently drop skb instead of failing with -EPERM. 391da177e4SLinus Torvalds * Detlev Wengorz : Copy protocol for fragments. 401da177e4SLinus Torvalds * Hirokazu Takahashi: HW checksumming for outgoing UDP 411da177e4SLinus Torvalds * datagrams. 421da177e4SLinus Torvalds * Hirokazu Takahashi: sendfile() on UDP works now. 431da177e4SLinus Torvalds */ 441da177e4SLinus Torvalds 451da177e4SLinus Torvalds #include <asm/uaccess.h> 461da177e4SLinus Torvalds #include <asm/system.h> 471da177e4SLinus Torvalds #include <linux/module.h> 481da177e4SLinus Torvalds #include <linux/types.h> 491da177e4SLinus Torvalds #include <linux/kernel.h> 501da177e4SLinus Torvalds #include <linux/mm.h> 511da177e4SLinus Torvalds #include <linux/string.h> 521da177e4SLinus Torvalds #include <linux/errno.h> 53a1f8e7f7SAl Viro #include <linux/highmem.h> 545a0e3ad6STejun Heo #include <linux/slab.h> 551da177e4SLinus Torvalds 561da177e4SLinus Torvalds #include <linux/socket.h> 571da177e4SLinus Torvalds #include <linux/sockios.h> 581da177e4SLinus Torvalds #include <linux/in.h> 591da177e4SLinus Torvalds #include <linux/inet.h> 601da177e4SLinus Torvalds #include <linux/netdevice.h> 611da177e4SLinus Torvalds #include <linux/etherdevice.h> 621da177e4SLinus Torvalds #include <linux/proc_fs.h> 631da177e4SLinus Torvalds #include <linux/stat.h> 641da177e4SLinus Torvalds #include <linux/init.h> 651da177e4SLinus Torvalds 661da177e4SLinus Torvalds #include <net/snmp.h> 671da177e4SLinus Torvalds #include <net/ip.h> 681da177e4SLinus Torvalds #include <net/protocol.h> 691da177e4SLinus Torvalds #include <net/route.h> 70cfacb057SPatrick McHardy #include <net/xfrm.h> 711da177e4SLinus Torvalds #include <linux/skbuff.h> 721da177e4SLinus Torvalds #include <net/sock.h> 731da177e4SLinus Torvalds #include <net/arp.h> 741da177e4SLinus Torvalds #include <net/icmp.h> 751da177e4SLinus Torvalds #include <net/checksum.h> 761da177e4SLinus Torvalds #include <net/inetpeer.h> 771da177e4SLinus Torvalds #include <linux/igmp.h> 781da177e4SLinus Torvalds #include <linux/netfilter_ipv4.h> 791da177e4SLinus Torvalds #include <linux/netfilter_bridge.h> 801da177e4SLinus Torvalds #include <linux/mroute.h> 811da177e4SLinus Torvalds #include <linux/netlink.h> 826cbb0df7SArnaldo Carvalho de Melo #include <linux/tcp.h> 831da177e4SLinus Torvalds 84ab32ea5dSBrian Haley int sysctl_ip_default_ttl __read_mostly = IPDEFTTL; 85323e126fSDavid S. Miller EXPORT_SYMBOL(sysctl_ip_default_ttl); 861da177e4SLinus Torvalds 871da177e4SLinus Torvalds /* Generate a checksum for an outgoing IP datagram. */ 881da177e4SLinus Torvalds __inline__ void ip_send_check(struct iphdr *iph) 891da177e4SLinus Torvalds { 901da177e4SLinus Torvalds iph->check = 0; 911da177e4SLinus Torvalds iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); 921da177e4SLinus Torvalds } 934bc2f18bSEric Dumazet EXPORT_SYMBOL(ip_send_check); 941da177e4SLinus Torvalds 95c439cb2eSHerbert Xu int __ip_local_out(struct sk_buff *skb) 96c439cb2eSHerbert Xu { 97c439cb2eSHerbert Xu struct iphdr *iph = ip_hdr(skb); 98c439cb2eSHerbert Xu 99c439cb2eSHerbert Xu iph->tot_len = htons(skb->len); 100c439cb2eSHerbert Xu ip_send_check(iph); 1019bbc768aSJan Engelhardt return nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, skb, NULL, 1029bbc768aSJan Engelhardt skb_dst(skb)->dev, dst_output); 103c439cb2eSHerbert Xu } 104c439cb2eSHerbert Xu 105c439cb2eSHerbert Xu int ip_local_out(struct sk_buff *skb) 106c439cb2eSHerbert Xu { 107c439cb2eSHerbert Xu int err; 108c439cb2eSHerbert Xu 109c439cb2eSHerbert Xu err = __ip_local_out(skb); 110c439cb2eSHerbert Xu if (likely(err == 1)) 111c439cb2eSHerbert Xu err = dst_output(skb); 112c439cb2eSHerbert Xu 113c439cb2eSHerbert Xu return err; 114c439cb2eSHerbert Xu } 115c439cb2eSHerbert Xu EXPORT_SYMBOL_GPL(ip_local_out); 116c439cb2eSHerbert Xu 1171da177e4SLinus Torvalds /* dev_loopback_xmit for use with netfilter. */ 1181da177e4SLinus Torvalds static int ip_dev_loopback_xmit(struct sk_buff *newskb) 1191da177e4SLinus Torvalds { 120459a98edSArnaldo Carvalho de Melo skb_reset_mac_header(newskb); 121bbe735e4SArnaldo Carvalho de Melo __skb_pull(newskb, skb_network_offset(newskb)); 1221da177e4SLinus Torvalds newskb->pkt_type = PACKET_LOOPBACK; 1231da177e4SLinus Torvalds newskb->ip_summed = CHECKSUM_UNNECESSARY; 124adf30907SEric Dumazet WARN_ON(!skb_dst(newskb)); 125e30b38c2SEric Dumazet netif_rx_ni(newskb); 1261da177e4SLinus Torvalds return 0; 1271da177e4SLinus Torvalds } 1281da177e4SLinus Torvalds 1291da177e4SLinus Torvalds static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) 1301da177e4SLinus Torvalds { 1311da177e4SLinus Torvalds int ttl = inet->uc_ttl; 1321da177e4SLinus Torvalds 1331da177e4SLinus Torvalds if (ttl < 0) 134323e126fSDavid S. Miller ttl = ip4_dst_hoplimit(dst); 1351da177e4SLinus Torvalds return ttl; 1361da177e4SLinus Torvalds } 1371da177e4SLinus Torvalds 1381da177e4SLinus Torvalds /* 1391da177e4SLinus Torvalds * Add an ip header to a skbuff and send it out. 1401da177e4SLinus Torvalds * 1411da177e4SLinus Torvalds */ 1421da177e4SLinus Torvalds int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, 143f6d8bd05SEric Dumazet __be32 saddr, __be32 daddr, struct ip_options_rcu *opt) 1441da177e4SLinus Torvalds { 1451da177e4SLinus Torvalds struct inet_sock *inet = inet_sk(sk); 146511c3f92SEric Dumazet struct rtable *rt = skb_rtable(skb); 1471da177e4SLinus Torvalds struct iphdr *iph; 1481da177e4SLinus Torvalds 1491da177e4SLinus Torvalds /* Build the IP header. */ 150f6d8bd05SEric Dumazet skb_push(skb, sizeof(struct iphdr) + (opt ? opt->opt.optlen : 0)); 1518856dfa3SArnaldo Carvalho de Melo skb_reset_network_header(skb); 152eddc9ec5SArnaldo Carvalho de Melo iph = ip_hdr(skb); 1531da177e4SLinus Torvalds iph->version = 4; 1541da177e4SLinus Torvalds iph->ihl = 5; 1551da177e4SLinus Torvalds iph->tos = inet->tos; 156d8d1f30bSChangli Gao if (ip_dont_fragment(sk, &rt->dst)) 1571da177e4SLinus Torvalds iph->frag_off = htons(IP_DF); 1581da177e4SLinus Torvalds else 1591da177e4SLinus Torvalds iph->frag_off = 0; 160d8d1f30bSChangli Gao iph->ttl = ip_select_ttl(inet, &rt->dst); 161dd927a26SDavid S. Miller iph->daddr = (opt && opt->opt.srr ? opt->opt.faddr : daddr); 162dd927a26SDavid S. Miller iph->saddr = saddr; 1631da177e4SLinus Torvalds iph->protocol = sk->sk_protocol; 164d8d1f30bSChangli Gao ip_select_ident(iph, &rt->dst, sk); 1651da177e4SLinus Torvalds 166f6d8bd05SEric Dumazet if (opt && opt->opt.optlen) { 167f6d8bd05SEric Dumazet iph->ihl += opt->opt.optlen>>2; 168f6d8bd05SEric Dumazet ip_options_build(skb, &opt->opt, daddr, rt, 0); 1691da177e4SLinus Torvalds } 1701da177e4SLinus Torvalds 1711da177e4SLinus Torvalds skb->priority = sk->sk_priority; 1724a19ec58SLaszlo Attila Toth skb->mark = sk->sk_mark; 1731da177e4SLinus Torvalds 1741da177e4SLinus Torvalds /* Send it out. */ 175c439cb2eSHerbert Xu return ip_local_out(skb); 1761da177e4SLinus Torvalds } 177d8c97a94SArnaldo Carvalho de Melo EXPORT_SYMBOL_GPL(ip_build_and_send_pkt); 178d8c97a94SArnaldo Carvalho de Melo 1791da177e4SLinus Torvalds static inline int ip_finish_output2(struct sk_buff *skb) 1801da177e4SLinus Torvalds { 181adf30907SEric Dumazet struct dst_entry *dst = skb_dst(skb); 18280787ebcSMitsuru Chinen struct rtable *rt = (struct rtable *)dst; 1831da177e4SLinus Torvalds struct net_device *dev = dst->dev; 184c2636b4dSChuck Lever unsigned int hh_len = LL_RESERVED_SPACE(dev); 185f6b72b62SDavid S. Miller struct neighbour *neigh; 1861da177e4SLinus Torvalds 187edf391ffSNeil Horman if (rt->rt_type == RTN_MULTICAST) { 188edf391ffSNeil Horman IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTMCAST, skb->len); 189edf391ffSNeil Horman } else if (rt->rt_type == RTN_BROADCAST) 190edf391ffSNeil Horman IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTBCAST, skb->len); 19180787ebcSMitsuru Chinen 1921da177e4SLinus Torvalds /* Be paranoid, rather than too clever. */ 1933b04dddeSStephen Hemminger if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { 1941da177e4SLinus Torvalds struct sk_buff *skb2; 1951da177e4SLinus Torvalds 1961da177e4SLinus Torvalds skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); 1971da177e4SLinus Torvalds if (skb2 == NULL) { 1981da177e4SLinus Torvalds kfree_skb(skb); 1991da177e4SLinus Torvalds return -ENOMEM; 2001da177e4SLinus Torvalds } 2011da177e4SLinus Torvalds if (skb->sk) 2021da177e4SLinus Torvalds skb_set_owner_w(skb2, skb->sk); 2031da177e4SLinus Torvalds kfree_skb(skb); 2041da177e4SLinus Torvalds skb = skb2; 2051da177e4SLinus Torvalds } 2061da177e4SLinus Torvalds 207*f2c31e32SEric Dumazet rcu_read_lock(); 20869cce1d1SDavid S. Miller neigh = dst_get_neighbour(dst); 209*f2c31e32SEric Dumazet if (neigh) { 210*f2c31e32SEric Dumazet int res = neigh_output(neigh, skb); 211*f2c31e32SEric Dumazet 212*f2c31e32SEric Dumazet rcu_read_unlock(); 213*f2c31e32SEric Dumazet return res; 214*f2c31e32SEric Dumazet } 215*f2c31e32SEric Dumazet rcu_read_unlock(); 21605e3aa09SDavid S. Miller 2171da177e4SLinus Torvalds if (net_ratelimit()) 2181da177e4SLinus Torvalds printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n"); 2191da177e4SLinus Torvalds kfree_skb(skb); 2201da177e4SLinus Torvalds return -EINVAL; 2211da177e4SLinus Torvalds } 2221da177e4SLinus Torvalds 223628a5c56SJohn Heffner static inline int ip_skb_dst_mtu(struct sk_buff *skb) 224628a5c56SJohn Heffner { 225628a5c56SJohn Heffner struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL; 226628a5c56SJohn Heffner 227628a5c56SJohn Heffner return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ? 228adf30907SEric Dumazet skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); 229628a5c56SJohn Heffner } 230628a5c56SJohn Heffner 231861d0486SPatrick McHardy static int ip_finish_output(struct sk_buff *skb) 2321da177e4SLinus Torvalds { 2335c901daaSPatrick McHardy #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) 2345c901daaSPatrick McHardy /* Policy lookup after SNAT yielded a new policy */ 235adf30907SEric Dumazet if (skb_dst(skb)->xfrm != NULL) { 23648d5cad8SPatrick McHardy IPCB(skb)->flags |= IPSKB_REROUTED; 23748d5cad8SPatrick McHardy return dst_output(skb); 23848d5cad8SPatrick McHardy } 2395c901daaSPatrick McHardy #endif 240628a5c56SJohn Heffner if (skb->len > ip_skb_dst_mtu(skb) && !skb_is_gso(skb)) 2411bd9bef6SPatrick McHardy return ip_fragment(skb, ip_finish_output2); 2421bd9bef6SPatrick McHardy else 2431bd9bef6SPatrick McHardy return ip_finish_output2(skb); 2441da177e4SLinus Torvalds } 2451da177e4SLinus Torvalds 2461da177e4SLinus Torvalds int ip_mc_output(struct sk_buff *skb) 2471da177e4SLinus Torvalds { 2481da177e4SLinus Torvalds struct sock *sk = skb->sk; 249511c3f92SEric Dumazet struct rtable *rt = skb_rtable(skb); 250d8d1f30bSChangli Gao struct net_device *dev = rt->dst.dev; 2511da177e4SLinus Torvalds 2521da177e4SLinus Torvalds /* 2531da177e4SLinus Torvalds * If the indicated interface is up and running, send the packet. 2541da177e4SLinus Torvalds */ 255edf391ffSNeil Horman IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); 2561da177e4SLinus Torvalds 2571da177e4SLinus Torvalds skb->dev = dev; 2581da177e4SLinus Torvalds skb->protocol = htons(ETH_P_IP); 2591da177e4SLinus Torvalds 2601da177e4SLinus Torvalds /* 2611da177e4SLinus Torvalds * Multicasts are looped back for other local users 2621da177e4SLinus Torvalds */ 2631da177e4SLinus Torvalds 2641da177e4SLinus Torvalds if (rt->rt_flags&RTCF_MULTICAST) { 2657ad6848cSOctavian Purdila if (sk_mc_loop(sk) 2661da177e4SLinus Torvalds #ifdef CONFIG_IP_MROUTE 2671da177e4SLinus Torvalds /* Small optimization: do not loopback not local frames, 2681da177e4SLinus Torvalds which returned after forwarding; they will be dropped 2691da177e4SLinus Torvalds by ip_mr_input in any case. 2701da177e4SLinus Torvalds Note, that local frames are looped back to be delivered 2711da177e4SLinus Torvalds to local recipients. 2721da177e4SLinus Torvalds 2731da177e4SLinus Torvalds This check is duplicated in ip_mr_input at the moment. 2741da177e4SLinus Torvalds */ 2759d4fb27dSJoe Perches && 2769d4fb27dSJoe Perches ((rt->rt_flags & RTCF_LOCAL) || 2779d4fb27dSJoe Perches !(IPCB(skb)->flags & IPSKB_FORWARDED)) 2781da177e4SLinus Torvalds #endif 2791da177e4SLinus Torvalds ) { 2801da177e4SLinus Torvalds struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 2811da177e4SLinus Torvalds if (newskb) 2829bbc768aSJan Engelhardt NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, 2839bbc768aSJan Engelhardt newskb, NULL, newskb->dev, 2841da177e4SLinus Torvalds ip_dev_loopback_xmit); 2851da177e4SLinus Torvalds } 2861da177e4SLinus Torvalds 2871da177e4SLinus Torvalds /* Multicasts with ttl 0 must not go beyond the host */ 2881da177e4SLinus Torvalds 289eddc9ec5SArnaldo Carvalho de Melo if (ip_hdr(skb)->ttl == 0) { 2901da177e4SLinus Torvalds kfree_skb(skb); 2911da177e4SLinus Torvalds return 0; 2921da177e4SLinus Torvalds } 2931da177e4SLinus Torvalds } 2941da177e4SLinus Torvalds 2951da177e4SLinus Torvalds if (rt->rt_flags&RTCF_BROADCAST) { 2961da177e4SLinus Torvalds struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); 2971da177e4SLinus Torvalds if (newskb) 2989bbc768aSJan Engelhardt NF_HOOK(NFPROTO_IPV4, NF_INET_POST_ROUTING, newskb, 2999bbc768aSJan Engelhardt NULL, newskb->dev, ip_dev_loopback_xmit); 3001da177e4SLinus Torvalds } 3011da177e4SLinus Torvalds 3029bbc768aSJan Engelhardt return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb, NULL, 3039bbc768aSJan Engelhardt skb->dev, ip_finish_output, 30448d5cad8SPatrick McHardy !(IPCB(skb)->flags & IPSKB_REROUTED)); 3051da177e4SLinus Torvalds } 3061da177e4SLinus Torvalds 3071da177e4SLinus Torvalds int ip_output(struct sk_buff *skb) 3081da177e4SLinus Torvalds { 309adf30907SEric Dumazet struct net_device *dev = skb_dst(skb)->dev; 3101bd9bef6SPatrick McHardy 311edf391ffSNeil Horman IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); 3121da177e4SLinus Torvalds 3131bd9bef6SPatrick McHardy skb->dev = dev; 3141bd9bef6SPatrick McHardy skb->protocol = htons(ETH_P_IP); 3151bd9bef6SPatrick McHardy 3169bbc768aSJan Engelhardt return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING, skb, NULL, dev, 31748d5cad8SPatrick McHardy ip_finish_output, 31848d5cad8SPatrick McHardy !(IPCB(skb)->flags & IPSKB_REROUTED)); 3191da177e4SLinus Torvalds } 3201da177e4SLinus Torvalds 321d9d8da80SDavid S. Miller int ip_queue_xmit(struct sk_buff *skb, struct flowi *fl) 3221da177e4SLinus Torvalds { 323e89862f4SDavid S. Miller struct sock *sk = skb->sk; 3241da177e4SLinus Torvalds struct inet_sock *inet = inet_sk(sk); 325f6d8bd05SEric Dumazet struct ip_options_rcu *inet_opt; 326b57ae01aSDavid S. Miller struct flowi4 *fl4; 3271da177e4SLinus Torvalds struct rtable *rt; 3281da177e4SLinus Torvalds struct iphdr *iph; 329ab6e3febSEric Dumazet int res; 3301da177e4SLinus Torvalds 3311da177e4SLinus Torvalds /* Skip all of this if the packet is already routed, 3321da177e4SLinus Torvalds * f.e. by something like SCTP. 3331da177e4SLinus Torvalds */ 334ab6e3febSEric Dumazet rcu_read_lock(); 335f6d8bd05SEric Dumazet inet_opt = rcu_dereference(inet->inet_opt); 336ea4fc0d6SDavid S. Miller fl4 = &fl->u.ip4; 337511c3f92SEric Dumazet rt = skb_rtable(skb); 3381da177e4SLinus Torvalds if (rt != NULL) 3391da177e4SLinus Torvalds goto packet_routed; 3401da177e4SLinus Torvalds 3411da177e4SLinus Torvalds /* Make sure we can route this packet. */ 3421da177e4SLinus Torvalds rt = (struct rtable *)__sk_dst_check(sk, 0); 3431da177e4SLinus Torvalds if (rt == NULL) { 3443ca3c68eSAl Viro __be32 daddr; 3451da177e4SLinus Torvalds 3461da177e4SLinus Torvalds /* Use correct destination address if we have options. */ 347c720c7e8SEric Dumazet daddr = inet->inet_daddr; 348f6d8bd05SEric Dumazet if (inet_opt && inet_opt->opt.srr) 349f6d8bd05SEric Dumazet daddr = inet_opt->opt.faddr; 3501da177e4SLinus Torvalds 3511da177e4SLinus Torvalds /* If this fails, retransmit mechanism of transport layer will 3521da177e4SLinus Torvalds * keep trying until route appears or the connection times 3531da177e4SLinus Torvalds * itself out. 3541da177e4SLinus Torvalds */ 355b57ae01aSDavid S. Miller rt = ip_route_output_ports(sock_net(sk), fl4, sk, 35678fbfd8aSDavid S. Miller daddr, inet->inet_saddr, 35778fbfd8aSDavid S. Miller inet->inet_dport, 35878fbfd8aSDavid S. Miller inet->inet_sport, 35978fbfd8aSDavid S. Miller sk->sk_protocol, 36078fbfd8aSDavid S. Miller RT_CONN_FLAGS(sk), 36178fbfd8aSDavid S. Miller sk->sk_bound_dev_if); 362b23dd4feSDavid S. Miller if (IS_ERR(rt)) 3631da177e4SLinus Torvalds goto no_route; 364d8d1f30bSChangli Gao sk_setup_caps(sk, &rt->dst); 3651da177e4SLinus Torvalds } 366d8d1f30bSChangli Gao skb_dst_set_noref(skb, &rt->dst); 3671da177e4SLinus Torvalds 3681da177e4SLinus Torvalds packet_routed: 369ea4fc0d6SDavid S. Miller if (inet_opt && inet_opt->opt.is_strictroute && fl4->daddr != rt->rt_gateway) 3701da177e4SLinus Torvalds goto no_route; 3711da177e4SLinus Torvalds 3721da177e4SLinus Torvalds /* OK, we know where to send it, allocate and build IP header. */ 373f6d8bd05SEric Dumazet skb_push(skb, sizeof(struct iphdr) + (inet_opt ? inet_opt->opt.optlen : 0)); 3748856dfa3SArnaldo Carvalho de Melo skb_reset_network_header(skb); 375eddc9ec5SArnaldo Carvalho de Melo iph = ip_hdr(skb); 376714e85beSAl Viro *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff)); 377d8d1f30bSChangli Gao if (ip_dont_fragment(sk, &rt->dst) && !skb->local_df) 3781da177e4SLinus Torvalds iph->frag_off = htons(IP_DF); 3791da177e4SLinus Torvalds else 3801da177e4SLinus Torvalds iph->frag_off = 0; 381d8d1f30bSChangli Gao iph->ttl = ip_select_ttl(inet, &rt->dst); 3821da177e4SLinus Torvalds iph->protocol = sk->sk_protocol; 383ea4fc0d6SDavid S. Miller iph->saddr = fl4->saddr; 384ea4fc0d6SDavid S. Miller iph->daddr = fl4->daddr; 3851da177e4SLinus Torvalds /* Transport layer set skb->h.foo itself. */ 3861da177e4SLinus Torvalds 387f6d8bd05SEric Dumazet if (inet_opt && inet_opt->opt.optlen) { 388f6d8bd05SEric Dumazet iph->ihl += inet_opt->opt.optlen >> 2; 389f6d8bd05SEric Dumazet ip_options_build(skb, &inet_opt->opt, inet->inet_daddr, rt, 0); 3901da177e4SLinus Torvalds } 3911da177e4SLinus Torvalds 392d8d1f30bSChangli Gao ip_select_ident_more(iph, &rt->dst, sk, 3937967168cSHerbert Xu (skb_shinfo(skb)->gso_segs ?: 1) - 1); 3941da177e4SLinus Torvalds 3951da177e4SLinus Torvalds skb->priority = sk->sk_priority; 3964a19ec58SLaszlo Attila Toth skb->mark = sk->sk_mark; 3971da177e4SLinus Torvalds 398ab6e3febSEric Dumazet res = ip_local_out(skb); 399ab6e3febSEric Dumazet rcu_read_unlock(); 400ab6e3febSEric Dumazet return res; 4011da177e4SLinus Torvalds 4021da177e4SLinus Torvalds no_route: 403ab6e3febSEric Dumazet rcu_read_unlock(); 4045e38e270SPavel Emelyanov IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); 4051da177e4SLinus Torvalds kfree_skb(skb); 4061da177e4SLinus Torvalds return -EHOSTUNREACH; 4071da177e4SLinus Torvalds } 4084bc2f18bSEric Dumazet EXPORT_SYMBOL(ip_queue_xmit); 4091da177e4SLinus Torvalds 4101da177e4SLinus Torvalds 4111da177e4SLinus Torvalds static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) 4121da177e4SLinus Torvalds { 4131da177e4SLinus Torvalds to->pkt_type = from->pkt_type; 4141da177e4SLinus Torvalds to->priority = from->priority; 4151da177e4SLinus Torvalds to->protocol = from->protocol; 416adf30907SEric Dumazet skb_dst_drop(to); 417fe76cda3SEric Dumazet skb_dst_copy(to, from); 4181da177e4SLinus Torvalds to->dev = from->dev; 41982e91ffeSThomas Graf to->mark = from->mark; 4201da177e4SLinus Torvalds 4211da177e4SLinus Torvalds /* Copy the flags to each fragment. */ 4221da177e4SLinus Torvalds IPCB(to)->flags = IPCB(from)->flags; 4231da177e4SLinus Torvalds 4241da177e4SLinus Torvalds #ifdef CONFIG_NET_SCHED 4251da177e4SLinus Torvalds to->tc_index = from->tc_index; 4261da177e4SLinus Torvalds #endif 427e7ac05f3SYasuyuki Kozakai nf_copy(to, from); 428ba9dda3aSJozsef Kadlecsik #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ 429ba9dda3aSJozsef Kadlecsik defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) 430ba9dda3aSJozsef Kadlecsik to->nf_trace = from->nf_trace; 431ba9dda3aSJozsef Kadlecsik #endif 432c98d80edSJulian Anastasov #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) 433c98d80edSJulian Anastasov to->ipvs_property = from->ipvs_property; 434c98d80edSJulian Anastasov #endif 435984bc16cSJames Morris skb_copy_secmark(to, from); 4361da177e4SLinus Torvalds } 4371da177e4SLinus Torvalds 4381da177e4SLinus Torvalds /* 4391da177e4SLinus Torvalds * This IP datagram is too large to be sent in one piece. Break it up into 4401da177e4SLinus Torvalds * smaller pieces (each of size equal to IP header plus 4411da177e4SLinus Torvalds * a block of the data of the original IP data part) that will yet fit in a 4421da177e4SLinus Torvalds * single device frame, and queue such a frame for sending. 4431da177e4SLinus Torvalds */ 4441da177e4SLinus Torvalds 4452e2f7aefSPatrick McHardy int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) 4461da177e4SLinus Torvalds { 4471da177e4SLinus Torvalds struct iphdr *iph; 4481da177e4SLinus Torvalds int ptr; 4491da177e4SLinus Torvalds struct net_device *dev; 4501da177e4SLinus Torvalds struct sk_buff *skb2; 451c893b806SChangli Gao unsigned int mtu, hlen, left, len, ll_rs; 4521da177e4SLinus Torvalds int offset; 45376ab608dSAlexey Dobriyan __be16 not_last_frag; 454511c3f92SEric Dumazet struct rtable *rt = skb_rtable(skb); 4551da177e4SLinus Torvalds int err = 0; 4561da177e4SLinus Torvalds 457d8d1f30bSChangli Gao dev = rt->dst.dev; 4581da177e4SLinus Torvalds 4591da177e4SLinus Torvalds /* 4601da177e4SLinus Torvalds * Point into the IP datagram header. 4611da177e4SLinus Torvalds */ 4621da177e4SLinus Torvalds 463eddc9ec5SArnaldo Carvalho de Melo iph = ip_hdr(skb); 4641da177e4SLinus Torvalds 4651da177e4SLinus Torvalds if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) { 4665e38e270SPavel Emelyanov IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); 4671da177e4SLinus Torvalds icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 468628a5c56SJohn Heffner htonl(ip_skb_dst_mtu(skb))); 4691da177e4SLinus Torvalds kfree_skb(skb); 4701da177e4SLinus Torvalds return -EMSGSIZE; 4711da177e4SLinus Torvalds } 4721da177e4SLinus Torvalds 4731da177e4SLinus Torvalds /* 4741da177e4SLinus Torvalds * Setup starting values. 4751da177e4SLinus Torvalds */ 4761da177e4SLinus Torvalds 4771da177e4SLinus Torvalds hlen = iph->ihl * 4; 478d8d1f30bSChangli Gao mtu = dst_mtu(&rt->dst) - hlen; /* Size of data space */ 4796c79bf0fSBart De Schuymer #ifdef CONFIG_BRIDGE_NETFILTER 4806c79bf0fSBart De Schuymer if (skb->nf_bridge) 4816c79bf0fSBart De Schuymer mtu -= nf_bridge_mtu_reduction(skb); 4826c79bf0fSBart De Schuymer #endif 48389cee8b1SHerbert Xu IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; 4841da177e4SLinus Torvalds 4851da177e4SLinus Torvalds /* When frag_list is given, use it. First, check its validity: 4861da177e4SLinus Torvalds * some transformers could create wrong frag_list or break existing 4871da177e4SLinus Torvalds * one, it is not prohibited. In this case fall back to copying. 4881da177e4SLinus Torvalds * 4891da177e4SLinus Torvalds * LATER: this step can be merged to real generation of fragments, 4901da177e4SLinus Torvalds * we can switch to copy when see the first bad fragment. 4911da177e4SLinus Torvalds */ 49221dc3301SDavid S. Miller if (skb_has_frag_list(skb)) { 4933d13008eSEric Dumazet struct sk_buff *frag, *frag2; 4941da177e4SLinus Torvalds int first_len = skb_pagelen(skb); 4951da177e4SLinus Torvalds 4961da177e4SLinus Torvalds if (first_len - hlen > mtu || 4971da177e4SLinus Torvalds ((first_len - hlen) & 7) || 49856f8a75cSPaul Gortmaker ip_is_fragment(iph) || 4991da177e4SLinus Torvalds skb_cloned(skb)) 5001da177e4SLinus Torvalds goto slow_path; 5011da177e4SLinus Torvalds 502d7fcf1a5SDavid S. Miller skb_walk_frags(skb, frag) { 5031da177e4SLinus Torvalds /* Correct geometry. */ 5041da177e4SLinus Torvalds if (frag->len > mtu || 5051da177e4SLinus Torvalds ((frag->len & 7) && frag->next) || 5061da177e4SLinus Torvalds skb_headroom(frag) < hlen) 5073d13008eSEric Dumazet goto slow_path_clean; 5081da177e4SLinus Torvalds 5091da177e4SLinus Torvalds /* Partially cloned skb? */ 5101da177e4SLinus Torvalds if (skb_shared(frag)) 5113d13008eSEric Dumazet goto slow_path_clean; 5122fdba6b0SHerbert Xu 5132fdba6b0SHerbert Xu BUG_ON(frag->sk); 5142fdba6b0SHerbert Xu if (skb->sk) { 5152fdba6b0SHerbert Xu frag->sk = skb->sk; 5162fdba6b0SHerbert Xu frag->destructor = sock_wfree; 5172fdba6b0SHerbert Xu } 5183d13008eSEric Dumazet skb->truesize -= frag->truesize; 5191da177e4SLinus Torvalds } 5201da177e4SLinus Torvalds 5211da177e4SLinus Torvalds /* Everything is OK. Generate! */ 5221da177e4SLinus Torvalds 5231da177e4SLinus Torvalds err = 0; 5241da177e4SLinus Torvalds offset = 0; 5251da177e4SLinus Torvalds frag = skb_shinfo(skb)->frag_list; 526d7fcf1a5SDavid S. Miller skb_frag_list_init(skb); 5271da177e4SLinus Torvalds skb->data_len = first_len - skb_headlen(skb); 5281da177e4SLinus Torvalds skb->len = first_len; 5291da177e4SLinus Torvalds iph->tot_len = htons(first_len); 5301da177e4SLinus Torvalds iph->frag_off = htons(IP_MF); 5311da177e4SLinus Torvalds ip_send_check(iph); 5321da177e4SLinus Torvalds 5331da177e4SLinus Torvalds for (;;) { 5341da177e4SLinus Torvalds /* Prepare header of the next frame, 5351da177e4SLinus Torvalds * before previous one went down. */ 5361da177e4SLinus Torvalds if (frag) { 5371da177e4SLinus Torvalds frag->ip_summed = CHECKSUM_NONE; 538badff6d0SArnaldo Carvalho de Melo skb_reset_transport_header(frag); 539e2d1bca7SArnaldo Carvalho de Melo __skb_push(frag, hlen); 540e2d1bca7SArnaldo Carvalho de Melo skb_reset_network_header(frag); 541d56f90a7SArnaldo Carvalho de Melo memcpy(skb_network_header(frag), iph, hlen); 542eddc9ec5SArnaldo Carvalho de Melo iph = ip_hdr(frag); 5431da177e4SLinus Torvalds iph->tot_len = htons(frag->len); 5441da177e4SLinus Torvalds ip_copy_metadata(frag, skb); 5451da177e4SLinus Torvalds if (offset == 0) 5461da177e4SLinus Torvalds ip_options_fragment(frag); 5471da177e4SLinus Torvalds offset += skb->len - hlen; 5481da177e4SLinus Torvalds iph->frag_off = htons(offset>>3); 5491da177e4SLinus Torvalds if (frag->next != NULL) 5501da177e4SLinus Torvalds iph->frag_off |= htons(IP_MF); 5511da177e4SLinus Torvalds /* Ready, complete checksum */ 5521da177e4SLinus Torvalds ip_send_check(iph); 5531da177e4SLinus Torvalds } 5541da177e4SLinus Torvalds 5551da177e4SLinus Torvalds err = output(skb); 5561da177e4SLinus Torvalds 557dafee490SWei Dong if (!err) 5585e38e270SPavel Emelyanov IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); 5591da177e4SLinus Torvalds if (err || !frag) 5601da177e4SLinus Torvalds break; 5611da177e4SLinus Torvalds 5621da177e4SLinus Torvalds skb = frag; 5631da177e4SLinus Torvalds frag = skb->next; 5641da177e4SLinus Torvalds skb->next = NULL; 5651da177e4SLinus Torvalds } 5661da177e4SLinus Torvalds 5671da177e4SLinus Torvalds if (err == 0) { 5685e38e270SPavel Emelyanov IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); 5691da177e4SLinus Torvalds return 0; 5701da177e4SLinus Torvalds } 5711da177e4SLinus Torvalds 5721da177e4SLinus Torvalds while (frag) { 5731da177e4SLinus Torvalds skb = frag->next; 5741da177e4SLinus Torvalds kfree_skb(frag); 5751da177e4SLinus Torvalds frag = skb; 5761da177e4SLinus Torvalds } 5775e38e270SPavel Emelyanov IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); 5781da177e4SLinus Torvalds return err; 5793d13008eSEric Dumazet 5803d13008eSEric Dumazet slow_path_clean: 5813d13008eSEric Dumazet skb_walk_frags(skb, frag2) { 5823d13008eSEric Dumazet if (frag2 == frag) 5833d13008eSEric Dumazet break; 5843d13008eSEric Dumazet frag2->sk = NULL; 5853d13008eSEric Dumazet frag2->destructor = NULL; 5863d13008eSEric Dumazet skb->truesize += frag2->truesize; 5873d13008eSEric Dumazet } 5881da177e4SLinus Torvalds } 5891da177e4SLinus Torvalds 5901da177e4SLinus Torvalds slow_path: 5911da177e4SLinus Torvalds left = skb->len - hlen; /* Space per frame */ 59249085bd7SGeorge Kadianakis ptr = hlen; /* Where to start from */ 5931da177e4SLinus Torvalds 5941da177e4SLinus Torvalds /* for bridged IP traffic encapsulated inside f.e. a vlan header, 5959bcfcaf5SStephen Hemminger * we need to make room for the encapsulating header 5969bcfcaf5SStephen Hemminger */ 597c893b806SChangli Gao ll_rs = LL_RESERVED_SPACE_EXTRA(rt->dst.dev, nf_bridge_pad(skb)); 5989bcfcaf5SStephen Hemminger 5991da177e4SLinus Torvalds /* 6001da177e4SLinus Torvalds * Fragment the datagram. 6011da177e4SLinus Torvalds */ 6021da177e4SLinus Torvalds 6031da177e4SLinus Torvalds offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; 6041da177e4SLinus Torvalds not_last_frag = iph->frag_off & htons(IP_MF); 6051da177e4SLinus Torvalds 6061da177e4SLinus Torvalds /* 6071da177e4SLinus Torvalds * Keep copying data until we run out. 6081da177e4SLinus Torvalds */ 6091da177e4SLinus Torvalds 6101da177e4SLinus Torvalds while (left > 0) { 6111da177e4SLinus Torvalds len = left; 6121da177e4SLinus Torvalds /* IF: it doesn't fit, use 'mtu' - the data space left */ 6131da177e4SLinus Torvalds if (len > mtu) 6141da177e4SLinus Torvalds len = mtu; 6151da177e4SLinus Torvalds /* IF: we are not sending up to and including the packet end 6161da177e4SLinus Torvalds then align the next start on an eight byte boundary */ 6171da177e4SLinus Torvalds if (len < left) { 6181da177e4SLinus Torvalds len &= ~7; 6191da177e4SLinus Torvalds } 6201da177e4SLinus Torvalds /* 6211da177e4SLinus Torvalds * Allocate buffer. 6221da177e4SLinus Torvalds */ 6231da177e4SLinus Torvalds 6241da177e4SLinus Torvalds if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) { 62564ce2073SPatrick McHardy NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n"); 6261da177e4SLinus Torvalds err = -ENOMEM; 6271da177e4SLinus Torvalds goto fail; 6281da177e4SLinus Torvalds } 6291da177e4SLinus Torvalds 6301da177e4SLinus Torvalds /* 6311da177e4SLinus Torvalds * Set up data on packet 6321da177e4SLinus Torvalds */ 6331da177e4SLinus Torvalds 6341da177e4SLinus Torvalds ip_copy_metadata(skb2, skb); 6351da177e4SLinus Torvalds skb_reserve(skb2, ll_rs); 6361da177e4SLinus Torvalds skb_put(skb2, len + hlen); 637c1d2bbe1SArnaldo Carvalho de Melo skb_reset_network_header(skb2); 638b0e380b1SArnaldo Carvalho de Melo skb2->transport_header = skb2->network_header + hlen; 6391da177e4SLinus Torvalds 6401da177e4SLinus Torvalds /* 6411da177e4SLinus Torvalds * Charge the memory for the fragment to any owner 6421da177e4SLinus Torvalds * it might possess 6431da177e4SLinus Torvalds */ 6441da177e4SLinus Torvalds 6451da177e4SLinus Torvalds if (skb->sk) 6461da177e4SLinus Torvalds skb_set_owner_w(skb2, skb->sk); 6471da177e4SLinus Torvalds 6481da177e4SLinus Torvalds /* 6491da177e4SLinus Torvalds * Copy the packet header into the new buffer. 6501da177e4SLinus Torvalds */ 6511da177e4SLinus Torvalds 652d626f62bSArnaldo Carvalho de Melo skb_copy_from_linear_data(skb, skb_network_header(skb2), hlen); 6531da177e4SLinus Torvalds 6541da177e4SLinus Torvalds /* 6551da177e4SLinus Torvalds * Copy a block of the IP datagram. 6561da177e4SLinus Torvalds */ 657bff9b61cSArnaldo Carvalho de Melo if (skb_copy_bits(skb, ptr, skb_transport_header(skb2), len)) 6581da177e4SLinus Torvalds BUG(); 6591da177e4SLinus Torvalds left -= len; 6601da177e4SLinus Torvalds 6611da177e4SLinus Torvalds /* 6621da177e4SLinus Torvalds * Fill in the new header fields. 6631da177e4SLinus Torvalds */ 664eddc9ec5SArnaldo Carvalho de Melo iph = ip_hdr(skb2); 6651da177e4SLinus Torvalds iph->frag_off = htons((offset >> 3)); 6661da177e4SLinus Torvalds 6671da177e4SLinus Torvalds /* ANK: dirty, but effective trick. Upgrade options only if 6681da177e4SLinus Torvalds * the segment to be fragmented was THE FIRST (otherwise, 6691da177e4SLinus Torvalds * options are already fixed) and make it ONCE 6701da177e4SLinus Torvalds * on the initial skb, so that all the following fragments 6711da177e4SLinus Torvalds * will inherit fixed options. 6721da177e4SLinus Torvalds */ 6731da177e4SLinus Torvalds if (offset == 0) 6741da177e4SLinus Torvalds ip_options_fragment(skb); 6751da177e4SLinus Torvalds 6761da177e4SLinus Torvalds /* 6771da177e4SLinus Torvalds * Added AC : If we are fragmenting a fragment that's not the 6781da177e4SLinus Torvalds * last fragment then keep MF on each bit 6791da177e4SLinus Torvalds */ 6801da177e4SLinus Torvalds if (left > 0 || not_last_frag) 6811da177e4SLinus Torvalds iph->frag_off |= htons(IP_MF); 6821da177e4SLinus Torvalds ptr += len; 6831da177e4SLinus Torvalds offset += len; 6841da177e4SLinus Torvalds 6851da177e4SLinus Torvalds /* 6861da177e4SLinus Torvalds * Put this fragment into the sending queue. 6871da177e4SLinus Torvalds */ 6881da177e4SLinus Torvalds iph->tot_len = htons(len + hlen); 6891da177e4SLinus Torvalds 6901da177e4SLinus Torvalds ip_send_check(iph); 6911da177e4SLinus Torvalds 6921da177e4SLinus Torvalds err = output(skb2); 6931da177e4SLinus Torvalds if (err) 6941da177e4SLinus Torvalds goto fail; 695dafee490SWei Dong 6965e38e270SPavel Emelyanov IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); 6971da177e4SLinus Torvalds } 6981da177e4SLinus Torvalds kfree_skb(skb); 6995e38e270SPavel Emelyanov IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); 7001da177e4SLinus Torvalds return err; 7011da177e4SLinus Torvalds 7021da177e4SLinus Torvalds fail: 7031da177e4SLinus Torvalds kfree_skb(skb); 7045e38e270SPavel Emelyanov IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); 7051da177e4SLinus Torvalds return err; 7061da177e4SLinus Torvalds } 7072e2f7aefSPatrick McHardy EXPORT_SYMBOL(ip_fragment); 7082e2f7aefSPatrick McHardy 7091da177e4SLinus Torvalds int 7101da177e4SLinus Torvalds ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) 7111da177e4SLinus Torvalds { 7121da177e4SLinus Torvalds struct iovec *iov = from; 7131da177e4SLinus Torvalds 71484fa7933SPatrick McHardy if (skb->ip_summed == CHECKSUM_PARTIAL) { 7151da177e4SLinus Torvalds if (memcpy_fromiovecend(to, iov, offset, len) < 0) 7161da177e4SLinus Torvalds return -EFAULT; 7171da177e4SLinus Torvalds } else { 71844bb9363SAl Viro __wsum csum = 0; 7191da177e4SLinus Torvalds if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0) 7201da177e4SLinus Torvalds return -EFAULT; 7211da177e4SLinus Torvalds skb->csum = csum_block_add(skb->csum, csum, odd); 7221da177e4SLinus Torvalds } 7231da177e4SLinus Torvalds return 0; 7241da177e4SLinus Torvalds } 7254bc2f18bSEric Dumazet EXPORT_SYMBOL(ip_generic_getfrag); 7261da177e4SLinus Torvalds 72744bb9363SAl Viro static inline __wsum 7281da177e4SLinus Torvalds csum_page(struct page *page, int offset, int copy) 7291da177e4SLinus Torvalds { 7301da177e4SLinus Torvalds char *kaddr; 73144bb9363SAl Viro __wsum csum; 7321da177e4SLinus Torvalds kaddr = kmap(page); 7331da177e4SLinus Torvalds csum = csum_partial(kaddr + offset, copy, 0); 7341da177e4SLinus Torvalds kunmap(page); 7351da177e4SLinus Torvalds return csum; 7361da177e4SLinus Torvalds } 7371da177e4SLinus Torvalds 7384b30b1c6SAdrian Bunk static inline int ip_ufo_append_data(struct sock *sk, 7391470ddf7SHerbert Xu struct sk_buff_head *queue, 740e89e9cf5SAnanda Raju int getfrag(void *from, char *to, int offset, int len, 741e89e9cf5SAnanda Raju int odd, struct sk_buff *skb), 742e89e9cf5SAnanda Raju void *from, int length, int hh_len, int fragheaderlen, 743d9be4f7aSBill Sommerfeld int transhdrlen, int maxfraglen, unsigned int flags) 744e89e9cf5SAnanda Raju { 745e89e9cf5SAnanda Raju struct sk_buff *skb; 746e89e9cf5SAnanda Raju int err; 747e89e9cf5SAnanda Raju 748e89e9cf5SAnanda Raju /* There is support for UDP fragmentation offload by network 749e89e9cf5SAnanda Raju * device, so create one single skb packet containing complete 750e89e9cf5SAnanda Raju * udp datagram 751e89e9cf5SAnanda Raju */ 7521470ddf7SHerbert Xu if ((skb = skb_peek_tail(queue)) == NULL) { 753e89e9cf5SAnanda Raju skb = sock_alloc_send_skb(sk, 754e89e9cf5SAnanda Raju hh_len + fragheaderlen + transhdrlen + 20, 755e89e9cf5SAnanda Raju (flags & MSG_DONTWAIT), &err); 756e89e9cf5SAnanda Raju 757e89e9cf5SAnanda Raju if (skb == NULL) 758e89e9cf5SAnanda Raju return err; 759e89e9cf5SAnanda Raju 760e89e9cf5SAnanda Raju /* reserve space for Hardware header */ 761e89e9cf5SAnanda Raju skb_reserve(skb, hh_len); 762e89e9cf5SAnanda Raju 763e89e9cf5SAnanda Raju /* create space for UDP/IP header */ 764e89e9cf5SAnanda Raju skb_put(skb, fragheaderlen + transhdrlen); 765e89e9cf5SAnanda Raju 766e89e9cf5SAnanda Raju /* initialize network header pointer */ 767c1d2bbe1SArnaldo Carvalho de Melo skb_reset_network_header(skb); 768e89e9cf5SAnanda Raju 769e89e9cf5SAnanda Raju /* initialize protocol header pointer */ 770b0e380b1SArnaldo Carvalho de Melo skb->transport_header = skb->network_header + fragheaderlen; 771e89e9cf5SAnanda Raju 77284fa7933SPatrick McHardy skb->ip_summed = CHECKSUM_PARTIAL; 773e89e9cf5SAnanda Raju skb->csum = 0; 774e89e9cf5SAnanda Raju 775e89e9cf5SAnanda Raju /* specify the length of each IP datagram fragment */ 776d9be4f7aSBill Sommerfeld skb_shinfo(skb)->gso_size = maxfraglen - fragheaderlen; 777f83ef8c0SHerbert Xu skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 7781470ddf7SHerbert Xu __skb_queue_tail(queue, skb); 779e89e9cf5SAnanda Raju } 780be9164e7SKostya B 781be9164e7SKostya B return skb_append_datato_frags(sk, skb, getfrag, from, 782be9164e7SKostya B (length - transhdrlen)); 783e89e9cf5SAnanda Raju } 784e89e9cf5SAnanda Raju 785f5fca608SDavid S. Miller static int __ip_append_data(struct sock *sk, 786f5fca608SDavid S. Miller struct flowi4 *fl4, 787f5fca608SDavid S. Miller struct sk_buff_head *queue, 7881470ddf7SHerbert Xu struct inet_cork *cork, 7891470ddf7SHerbert Xu int getfrag(void *from, char *to, int offset, 7901470ddf7SHerbert Xu int len, int odd, struct sk_buff *skb), 7911da177e4SLinus Torvalds void *from, int length, int transhdrlen, 7921da177e4SLinus Torvalds unsigned int flags) 7931da177e4SLinus Torvalds { 7941da177e4SLinus Torvalds struct inet_sock *inet = inet_sk(sk); 7951da177e4SLinus Torvalds struct sk_buff *skb; 7961da177e4SLinus Torvalds 79707df5294SHerbert Xu struct ip_options *opt = cork->opt; 7981da177e4SLinus Torvalds int hh_len; 7991da177e4SLinus Torvalds int exthdrlen; 8001da177e4SLinus Torvalds int mtu; 8011da177e4SLinus Torvalds int copy; 8021da177e4SLinus Torvalds int err; 8031da177e4SLinus Torvalds int offset = 0; 8041da177e4SLinus Torvalds unsigned int maxfraglen, fragheaderlen; 8051da177e4SLinus Torvalds int csummode = CHECKSUM_NONE; 8061470ddf7SHerbert Xu struct rtable *rt = (struct rtable *)cork->dst; 8071da177e4SLinus Torvalds 80896d7303eSSteffen Klassert skb = skb_peek_tail(queue); 80996d7303eSSteffen Klassert 81096d7303eSSteffen Klassert exthdrlen = !skb ? rt->dst.header_len : 0; 81107df5294SHerbert Xu mtu = cork->fragsize; 8121470ddf7SHerbert Xu 813d8d1f30bSChangli Gao hh_len = LL_RESERVED_SPACE(rt->dst.dev); 8141da177e4SLinus Torvalds 8151da177e4SLinus Torvalds fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); 8161da177e4SLinus Torvalds maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; 8171da177e4SLinus Torvalds 8181470ddf7SHerbert Xu if (cork->length + length > 0xFFFF - fragheaderlen) { 819f5fca608SDavid S. Miller ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, 820c720c7e8SEric Dumazet mtu-exthdrlen); 8211da177e4SLinus Torvalds return -EMSGSIZE; 8221da177e4SLinus Torvalds } 8231da177e4SLinus Torvalds 8241da177e4SLinus Torvalds /* 8251da177e4SLinus Torvalds * transhdrlen > 0 means that this is the first fragment and we wish 8261da177e4SLinus Torvalds * it won't be fragmented in the future. 8271da177e4SLinus Torvalds */ 8281da177e4SLinus Torvalds if (transhdrlen && 8291da177e4SLinus Torvalds length + fragheaderlen <= mtu && 830d8d1f30bSChangli Gao rt->dst.dev->features & NETIF_F_V4_CSUM && 8311da177e4SLinus Torvalds !exthdrlen) 83284fa7933SPatrick McHardy csummode = CHECKSUM_PARTIAL; 8331da177e4SLinus Torvalds 8341470ddf7SHerbert Xu cork->length += length; 83526cde9f7SHerbert Xu if (((length > mtu) || (skb && skb_is_gso(skb))) && 836be9164e7SKostya B (sk->sk_protocol == IPPROTO_UDP) && 837c146066aSSteffen Klassert (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len) { 8381470ddf7SHerbert Xu err = ip_ufo_append_data(sk, queue, getfrag, from, length, 8391470ddf7SHerbert Xu hh_len, fragheaderlen, transhdrlen, 840d9be4f7aSBill Sommerfeld maxfraglen, flags); 841baa829d8SPatrick McHardy if (err) 842e89e9cf5SAnanda Raju goto error; 843e89e9cf5SAnanda Raju return 0; 844e89e9cf5SAnanda Raju } 8451da177e4SLinus Torvalds 8461da177e4SLinus Torvalds /* So, what's going on in the loop below? 8471da177e4SLinus Torvalds * 8481da177e4SLinus Torvalds * We use calculated fragment length to generate chained skb, 8491da177e4SLinus Torvalds * each of segments is IP fragment ready for sending to network after 8501da177e4SLinus Torvalds * adding appropriate IP header. 8511da177e4SLinus Torvalds */ 8521da177e4SLinus Torvalds 85326cde9f7SHerbert Xu if (!skb) 8541da177e4SLinus Torvalds goto alloc_new_skb; 8551da177e4SLinus Torvalds 8561da177e4SLinus Torvalds while (length > 0) { 8571da177e4SLinus Torvalds /* Check if the remaining data fits into current packet. */ 8581da177e4SLinus Torvalds copy = mtu - skb->len; 8591da177e4SLinus Torvalds if (copy < length) 8601da177e4SLinus Torvalds copy = maxfraglen - skb->len; 8611da177e4SLinus Torvalds if (copy <= 0) { 8621da177e4SLinus Torvalds char *data; 8631da177e4SLinus Torvalds unsigned int datalen; 8641da177e4SLinus Torvalds unsigned int fraglen; 8651da177e4SLinus Torvalds unsigned int fraggap; 8661da177e4SLinus Torvalds unsigned int alloclen; 8671da177e4SLinus Torvalds struct sk_buff *skb_prev; 8681da177e4SLinus Torvalds alloc_new_skb: 8691da177e4SLinus Torvalds skb_prev = skb; 8701da177e4SLinus Torvalds if (skb_prev) 8711da177e4SLinus Torvalds fraggap = skb_prev->len - maxfraglen; 8721da177e4SLinus Torvalds else 8731da177e4SLinus Torvalds fraggap = 0; 8741da177e4SLinus Torvalds 8751da177e4SLinus Torvalds /* 8761da177e4SLinus Torvalds * If remaining data exceeds the mtu, 8771da177e4SLinus Torvalds * we know we need more fragment(s). 8781da177e4SLinus Torvalds */ 8791da177e4SLinus Torvalds datalen = length + fraggap; 8801da177e4SLinus Torvalds if (datalen > mtu - fragheaderlen) 8811da177e4SLinus Torvalds datalen = maxfraglen - fragheaderlen; 8821da177e4SLinus Torvalds fraglen = datalen + fragheaderlen; 8831da177e4SLinus Torvalds 8841da177e4SLinus Torvalds if ((flags & MSG_MORE) && 885d8d1f30bSChangli Gao !(rt->dst.dev->features&NETIF_F_SG)) 8861da177e4SLinus Torvalds alloclen = mtu; 8871da177e4SLinus Torvalds else 88859104f06SEric Dumazet alloclen = fraglen; 8891da177e4SLinus Torvalds 890353e5c9aSSteffen Klassert alloclen += exthdrlen; 891353e5c9aSSteffen Klassert 8921da177e4SLinus Torvalds /* The last fragment gets additional space at tail. 8931da177e4SLinus Torvalds * Note, with MSG_MORE we overallocate on fragments, 8941da177e4SLinus Torvalds * because we have no idea what fragment will be 8951da177e4SLinus Torvalds * the last. 8961da177e4SLinus Torvalds */ 89733f99dc7SSteffen Klassert if (datalen == length + fraggap) 898d8d1f30bSChangli Gao alloclen += rt->dst.trailer_len; 89933f99dc7SSteffen Klassert 9001da177e4SLinus Torvalds if (transhdrlen) { 9011da177e4SLinus Torvalds skb = sock_alloc_send_skb(sk, 9021da177e4SLinus Torvalds alloclen + hh_len + 15, 9031da177e4SLinus Torvalds (flags & MSG_DONTWAIT), &err); 9041da177e4SLinus Torvalds } else { 9051da177e4SLinus Torvalds skb = NULL; 9061da177e4SLinus Torvalds if (atomic_read(&sk->sk_wmem_alloc) <= 9071da177e4SLinus Torvalds 2 * sk->sk_sndbuf) 9081da177e4SLinus Torvalds skb = sock_wmalloc(sk, 9091da177e4SLinus Torvalds alloclen + hh_len + 15, 1, 9101da177e4SLinus Torvalds sk->sk_allocation); 9111da177e4SLinus Torvalds if (unlikely(skb == NULL)) 9121da177e4SLinus Torvalds err = -ENOBUFS; 91351f31cabSPatrick Ohly else 91451f31cabSPatrick Ohly /* only the initial fragment is 91551f31cabSPatrick Ohly time stamped */ 9161470ddf7SHerbert Xu cork->tx_flags = 0; 9171da177e4SLinus Torvalds } 9181da177e4SLinus Torvalds if (skb == NULL) 9191da177e4SLinus Torvalds goto error; 9201da177e4SLinus Torvalds 9211da177e4SLinus Torvalds /* 9221da177e4SLinus Torvalds * Fill in the control structures 9231da177e4SLinus Torvalds */ 9241da177e4SLinus Torvalds skb->ip_summed = csummode; 9251da177e4SLinus Torvalds skb->csum = 0; 9261da177e4SLinus Torvalds skb_reserve(skb, hh_len); 9271470ddf7SHerbert Xu skb_shinfo(skb)->tx_flags = cork->tx_flags; 9281da177e4SLinus Torvalds 9291da177e4SLinus Torvalds /* 9301da177e4SLinus Torvalds * Find where to start putting bytes. 9311da177e4SLinus Torvalds */ 932353e5c9aSSteffen Klassert data = skb_put(skb, fraglen + exthdrlen); 933c14d2450SArnaldo Carvalho de Melo skb_set_network_header(skb, exthdrlen); 934b0e380b1SArnaldo Carvalho de Melo skb->transport_header = (skb->network_header + 935b0e380b1SArnaldo Carvalho de Melo fragheaderlen); 936353e5c9aSSteffen Klassert data += fragheaderlen + exthdrlen; 9371da177e4SLinus Torvalds 9381da177e4SLinus Torvalds if (fraggap) { 9391da177e4SLinus Torvalds skb->csum = skb_copy_and_csum_bits( 9401da177e4SLinus Torvalds skb_prev, maxfraglen, 9411da177e4SLinus Torvalds data + transhdrlen, fraggap, 0); 9421da177e4SLinus Torvalds skb_prev->csum = csum_sub(skb_prev->csum, 9431da177e4SLinus Torvalds skb->csum); 9441da177e4SLinus Torvalds data += fraggap; 945e9fa4f7bSHerbert Xu pskb_trim_unique(skb_prev, maxfraglen); 9461da177e4SLinus Torvalds } 9471da177e4SLinus Torvalds 9481da177e4SLinus Torvalds copy = datalen - transhdrlen - fraggap; 9491da177e4SLinus Torvalds if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { 9501da177e4SLinus Torvalds err = -EFAULT; 9511da177e4SLinus Torvalds kfree_skb(skb); 9521da177e4SLinus Torvalds goto error; 9531da177e4SLinus Torvalds } 9541da177e4SLinus Torvalds 9551da177e4SLinus Torvalds offset += copy; 9561da177e4SLinus Torvalds length -= datalen - fraggap; 9571da177e4SLinus Torvalds transhdrlen = 0; 9581da177e4SLinus Torvalds exthdrlen = 0; 9591da177e4SLinus Torvalds csummode = CHECKSUM_NONE; 9601da177e4SLinus Torvalds 9611da177e4SLinus Torvalds /* 9621da177e4SLinus Torvalds * Put the packet on the pending queue. 9631da177e4SLinus Torvalds */ 9641470ddf7SHerbert Xu __skb_queue_tail(queue, skb); 9651da177e4SLinus Torvalds continue; 9661da177e4SLinus Torvalds } 9671da177e4SLinus Torvalds 9681da177e4SLinus Torvalds if (copy > length) 9691da177e4SLinus Torvalds copy = length; 9701da177e4SLinus Torvalds 971d8d1f30bSChangli Gao if (!(rt->dst.dev->features&NETIF_F_SG)) { 9721da177e4SLinus Torvalds unsigned int off; 9731da177e4SLinus Torvalds 9741da177e4SLinus Torvalds off = skb->len; 9751da177e4SLinus Torvalds if (getfrag(from, skb_put(skb, copy), 9761da177e4SLinus Torvalds offset, copy, off, skb) < 0) { 9771da177e4SLinus Torvalds __skb_trim(skb, off); 9781da177e4SLinus Torvalds err = -EFAULT; 9791da177e4SLinus Torvalds goto error; 9801da177e4SLinus Torvalds } 9811da177e4SLinus Torvalds } else { 9821da177e4SLinus Torvalds int i = skb_shinfo(skb)->nr_frags; 9831da177e4SLinus Torvalds skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; 9841470ddf7SHerbert Xu struct page *page = cork->page; 9851470ddf7SHerbert Xu int off = cork->off; 9861da177e4SLinus Torvalds unsigned int left; 9871da177e4SLinus Torvalds 9881da177e4SLinus Torvalds if (page && (left = PAGE_SIZE - off) > 0) { 9891da177e4SLinus Torvalds if (copy >= left) 9901da177e4SLinus Torvalds copy = left; 9911da177e4SLinus Torvalds if (page != frag->page) { 9921da177e4SLinus Torvalds if (i == MAX_SKB_FRAGS) { 9931da177e4SLinus Torvalds err = -EMSGSIZE; 9941da177e4SLinus Torvalds goto error; 9951da177e4SLinus Torvalds } 9961da177e4SLinus Torvalds get_page(page); 9971470ddf7SHerbert Xu skb_fill_page_desc(skb, i, page, off, 0); 9981da177e4SLinus Torvalds frag = &skb_shinfo(skb)->frags[i]; 9991da177e4SLinus Torvalds } 10001da177e4SLinus Torvalds } else if (i < MAX_SKB_FRAGS) { 10011da177e4SLinus Torvalds if (copy > PAGE_SIZE) 10021da177e4SLinus Torvalds copy = PAGE_SIZE; 10031da177e4SLinus Torvalds page = alloc_pages(sk->sk_allocation, 0); 10041da177e4SLinus Torvalds if (page == NULL) { 10051da177e4SLinus Torvalds err = -ENOMEM; 10061da177e4SLinus Torvalds goto error; 10071da177e4SLinus Torvalds } 10081470ddf7SHerbert Xu cork->page = page; 10091470ddf7SHerbert Xu cork->off = 0; 10101da177e4SLinus Torvalds 10111da177e4SLinus Torvalds skb_fill_page_desc(skb, i, page, 0, 0); 10121da177e4SLinus Torvalds frag = &skb_shinfo(skb)->frags[i]; 10131da177e4SLinus Torvalds } else { 10141da177e4SLinus Torvalds err = -EMSGSIZE; 10151da177e4SLinus Torvalds goto error; 10161da177e4SLinus Torvalds } 10171da177e4SLinus Torvalds if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) { 10181da177e4SLinus Torvalds err = -EFAULT; 10191da177e4SLinus Torvalds goto error; 10201da177e4SLinus Torvalds } 10211470ddf7SHerbert Xu cork->off += copy; 10221da177e4SLinus Torvalds frag->size += copy; 10231da177e4SLinus Torvalds skb->len += copy; 10241da177e4SLinus Torvalds skb->data_len += copy; 1025f945fa7aSHerbert Xu skb->truesize += copy; 1026f945fa7aSHerbert Xu atomic_add(copy, &sk->sk_wmem_alloc); 10271da177e4SLinus Torvalds } 10281da177e4SLinus Torvalds offset += copy; 10291da177e4SLinus Torvalds length -= copy; 10301da177e4SLinus Torvalds } 10311da177e4SLinus Torvalds 10321da177e4SLinus Torvalds return 0; 10331da177e4SLinus Torvalds 10341da177e4SLinus Torvalds error: 10351470ddf7SHerbert Xu cork->length -= length; 10365e38e270SPavel Emelyanov IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); 10371da177e4SLinus Torvalds return err; 10381da177e4SLinus Torvalds } 10391da177e4SLinus Torvalds 10401470ddf7SHerbert Xu static int ip_setup_cork(struct sock *sk, struct inet_cork *cork, 10411470ddf7SHerbert Xu struct ipcm_cookie *ipc, struct rtable **rtp) 10421470ddf7SHerbert Xu { 10431470ddf7SHerbert Xu struct inet_sock *inet = inet_sk(sk); 1044f6d8bd05SEric Dumazet struct ip_options_rcu *opt; 10451470ddf7SHerbert Xu struct rtable *rt; 10461470ddf7SHerbert Xu 10471470ddf7SHerbert Xu /* 10481470ddf7SHerbert Xu * setup for corking. 10491470ddf7SHerbert Xu */ 10501470ddf7SHerbert Xu opt = ipc->opt; 10511470ddf7SHerbert Xu if (opt) { 10521470ddf7SHerbert Xu if (cork->opt == NULL) { 10531470ddf7SHerbert Xu cork->opt = kmalloc(sizeof(struct ip_options) + 40, 10541470ddf7SHerbert Xu sk->sk_allocation); 10551470ddf7SHerbert Xu if (unlikely(cork->opt == NULL)) 10561470ddf7SHerbert Xu return -ENOBUFS; 10571470ddf7SHerbert Xu } 1058f6d8bd05SEric Dumazet memcpy(cork->opt, &opt->opt, sizeof(struct ip_options) + opt->opt.optlen); 10591470ddf7SHerbert Xu cork->flags |= IPCORK_OPT; 10601470ddf7SHerbert Xu cork->addr = ipc->addr; 10611470ddf7SHerbert Xu } 10621470ddf7SHerbert Xu rt = *rtp; 10631470ddf7SHerbert Xu if (unlikely(!rt)) 10641470ddf7SHerbert Xu return -EFAULT; 10651470ddf7SHerbert Xu /* 10661470ddf7SHerbert Xu * We steal reference to this route, caller should not release it 10671470ddf7SHerbert Xu */ 10681470ddf7SHerbert Xu *rtp = NULL; 10691470ddf7SHerbert Xu cork->fragsize = inet->pmtudisc == IP_PMTUDISC_PROBE ? 1070353e5c9aSSteffen Klassert rt->dst.dev->mtu : dst_mtu(&rt->dst); 10711470ddf7SHerbert Xu cork->dst = &rt->dst; 10721470ddf7SHerbert Xu cork->length = 0; 10731470ddf7SHerbert Xu cork->tx_flags = ipc->tx_flags; 10741470ddf7SHerbert Xu cork->page = NULL; 10751470ddf7SHerbert Xu cork->off = 0; 10761470ddf7SHerbert Xu 10771470ddf7SHerbert Xu return 0; 10781470ddf7SHerbert Xu } 10791470ddf7SHerbert Xu 10801470ddf7SHerbert Xu /* 10811470ddf7SHerbert Xu * ip_append_data() and ip_append_page() can make one large IP datagram 10821470ddf7SHerbert Xu * from many pieces of data. Each pieces will be holded on the socket 10831470ddf7SHerbert Xu * until ip_push_pending_frames() is called. Each piece can be a page 10841470ddf7SHerbert Xu * or non-page data. 10851470ddf7SHerbert Xu * 10861470ddf7SHerbert Xu * Not only UDP, other transport protocols - e.g. raw sockets - can use 10871470ddf7SHerbert Xu * this interface potentially. 10881470ddf7SHerbert Xu * 10891470ddf7SHerbert Xu * LATER: length must be adjusted by pad at tail, when it is required. 10901470ddf7SHerbert Xu */ 1091f5fca608SDavid S. Miller int ip_append_data(struct sock *sk, struct flowi4 *fl4, 10921470ddf7SHerbert Xu int getfrag(void *from, char *to, int offset, int len, 10931470ddf7SHerbert Xu int odd, struct sk_buff *skb), 10941470ddf7SHerbert Xu void *from, int length, int transhdrlen, 10951470ddf7SHerbert Xu struct ipcm_cookie *ipc, struct rtable **rtp, 10961470ddf7SHerbert Xu unsigned int flags) 10971470ddf7SHerbert Xu { 10981470ddf7SHerbert Xu struct inet_sock *inet = inet_sk(sk); 10991470ddf7SHerbert Xu int err; 11001470ddf7SHerbert Xu 11011470ddf7SHerbert Xu if (flags&MSG_PROBE) 11021470ddf7SHerbert Xu return 0; 11031470ddf7SHerbert Xu 11041470ddf7SHerbert Xu if (skb_queue_empty(&sk->sk_write_queue)) { 1105bdc712b4SDavid S. Miller err = ip_setup_cork(sk, &inet->cork.base, ipc, rtp); 11061470ddf7SHerbert Xu if (err) 11071470ddf7SHerbert Xu return err; 11081470ddf7SHerbert Xu } else { 11091470ddf7SHerbert Xu transhdrlen = 0; 11101470ddf7SHerbert Xu } 11111470ddf7SHerbert Xu 1112f5fca608SDavid S. Miller return __ip_append_data(sk, fl4, &sk->sk_write_queue, &inet->cork.base, getfrag, 11131470ddf7SHerbert Xu from, length, transhdrlen, flags); 11141470ddf7SHerbert Xu } 11151470ddf7SHerbert Xu 1116f5fca608SDavid S. Miller ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, 11171da177e4SLinus Torvalds int offset, size_t size, int flags) 11181da177e4SLinus Torvalds { 11191da177e4SLinus Torvalds struct inet_sock *inet = inet_sk(sk); 11201da177e4SLinus Torvalds struct sk_buff *skb; 11211da177e4SLinus Torvalds struct rtable *rt; 11221da177e4SLinus Torvalds struct ip_options *opt = NULL; 1123bdc712b4SDavid S. Miller struct inet_cork *cork; 11241da177e4SLinus Torvalds int hh_len; 11251da177e4SLinus Torvalds int mtu; 11261da177e4SLinus Torvalds int len; 11271da177e4SLinus Torvalds int err; 11281da177e4SLinus Torvalds unsigned int maxfraglen, fragheaderlen, fraggap; 11291da177e4SLinus Torvalds 11301da177e4SLinus Torvalds if (inet->hdrincl) 11311da177e4SLinus Torvalds return -EPERM; 11321da177e4SLinus Torvalds 11331da177e4SLinus Torvalds if (flags&MSG_PROBE) 11341da177e4SLinus Torvalds return 0; 11351da177e4SLinus Torvalds 11361da177e4SLinus Torvalds if (skb_queue_empty(&sk->sk_write_queue)) 11371da177e4SLinus Torvalds return -EINVAL; 11381da177e4SLinus Torvalds 1139bdc712b4SDavid S. Miller cork = &inet->cork.base; 1140bdc712b4SDavid S. Miller rt = (struct rtable *)cork->dst; 1141bdc712b4SDavid S. Miller if (cork->flags & IPCORK_OPT) 1142bdc712b4SDavid S. Miller opt = cork->opt; 11431da177e4SLinus Torvalds 1144d8d1f30bSChangli Gao if (!(rt->dst.dev->features&NETIF_F_SG)) 11451da177e4SLinus Torvalds return -EOPNOTSUPP; 11461da177e4SLinus Torvalds 1147d8d1f30bSChangli Gao hh_len = LL_RESERVED_SPACE(rt->dst.dev); 1148bdc712b4SDavid S. Miller mtu = cork->fragsize; 11491da177e4SLinus Torvalds 11501da177e4SLinus Torvalds fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); 11511da177e4SLinus Torvalds maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; 11521da177e4SLinus Torvalds 1153bdc712b4SDavid S. Miller if (cork->length + size > 0xFFFF - fragheaderlen) { 1154f5fca608SDavid S. Miller ip_local_error(sk, EMSGSIZE, fl4->daddr, inet->inet_dport, mtu); 11551da177e4SLinus Torvalds return -EMSGSIZE; 11561da177e4SLinus Torvalds } 11571da177e4SLinus Torvalds 11581da177e4SLinus Torvalds if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) 11591da177e4SLinus Torvalds return -EINVAL; 11601da177e4SLinus Torvalds 1161bdc712b4SDavid S. Miller cork->length += size; 116226cde9f7SHerbert Xu if ((size + skb->len > mtu) && 116326cde9f7SHerbert Xu (sk->sk_protocol == IPPROTO_UDP) && 1164d8d1f30bSChangli Gao (rt->dst.dev->features & NETIF_F_UFO)) { 11657967168cSHerbert Xu skb_shinfo(skb)->gso_size = mtu - fragheaderlen; 1166f83ef8c0SHerbert Xu skb_shinfo(skb)->gso_type = SKB_GSO_UDP; 11677967168cSHerbert Xu } 1168e89e9cf5SAnanda Raju 11691da177e4SLinus Torvalds 11701da177e4SLinus Torvalds while (size > 0) { 11711da177e4SLinus Torvalds int i; 11721da177e4SLinus Torvalds 117389114afdSHerbert Xu if (skb_is_gso(skb)) 1174e89e9cf5SAnanda Raju len = size; 1175e89e9cf5SAnanda Raju else { 1176e89e9cf5SAnanda Raju 11771da177e4SLinus Torvalds /* Check if the remaining data fits into current packet. */ 11781da177e4SLinus Torvalds len = mtu - skb->len; 11791da177e4SLinus Torvalds if (len < size) 11801da177e4SLinus Torvalds len = maxfraglen - skb->len; 1181e89e9cf5SAnanda Raju } 11821da177e4SLinus Torvalds if (len <= 0) { 11831da177e4SLinus Torvalds struct sk_buff *skb_prev; 11841da177e4SLinus Torvalds int alloclen; 11851da177e4SLinus Torvalds 11861da177e4SLinus Torvalds skb_prev = skb; 11871da177e4SLinus Torvalds fraggap = skb_prev->len - maxfraglen; 11881da177e4SLinus Torvalds 11891da177e4SLinus Torvalds alloclen = fragheaderlen + hh_len + fraggap + 15; 11901da177e4SLinus Torvalds skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); 11911da177e4SLinus Torvalds if (unlikely(!skb)) { 11921da177e4SLinus Torvalds err = -ENOBUFS; 11931da177e4SLinus Torvalds goto error; 11941da177e4SLinus Torvalds } 11951da177e4SLinus Torvalds 11961da177e4SLinus Torvalds /* 11971da177e4SLinus Torvalds * Fill in the control structures 11981da177e4SLinus Torvalds */ 11991da177e4SLinus Torvalds skb->ip_summed = CHECKSUM_NONE; 12001da177e4SLinus Torvalds skb->csum = 0; 12011da177e4SLinus Torvalds skb_reserve(skb, hh_len); 12021da177e4SLinus Torvalds 12031da177e4SLinus Torvalds /* 12041da177e4SLinus Torvalds * Find where to start putting bytes. 12051da177e4SLinus Torvalds */ 1206967b05f6SArnaldo Carvalho de Melo skb_put(skb, fragheaderlen + fraggap); 12072ca9e6f2SArnaldo Carvalho de Melo skb_reset_network_header(skb); 1208b0e380b1SArnaldo Carvalho de Melo skb->transport_header = (skb->network_header + 1209b0e380b1SArnaldo Carvalho de Melo fragheaderlen); 12101da177e4SLinus Torvalds if (fraggap) { 1211967b05f6SArnaldo Carvalho de Melo skb->csum = skb_copy_and_csum_bits(skb_prev, 1212967b05f6SArnaldo Carvalho de Melo maxfraglen, 12139c70220bSArnaldo Carvalho de Melo skb_transport_header(skb), 1214967b05f6SArnaldo Carvalho de Melo fraggap, 0); 12151da177e4SLinus Torvalds skb_prev->csum = csum_sub(skb_prev->csum, 12161da177e4SLinus Torvalds skb->csum); 1217e9fa4f7bSHerbert Xu pskb_trim_unique(skb_prev, maxfraglen); 12181da177e4SLinus Torvalds } 12191da177e4SLinus Torvalds 12201da177e4SLinus Torvalds /* 12211da177e4SLinus Torvalds * Put the packet on the pending queue. 12221da177e4SLinus Torvalds */ 12231da177e4SLinus Torvalds __skb_queue_tail(&sk->sk_write_queue, skb); 12241da177e4SLinus Torvalds continue; 12251da177e4SLinus Torvalds } 12261da177e4SLinus Torvalds 12271da177e4SLinus Torvalds i = skb_shinfo(skb)->nr_frags; 12281da177e4SLinus Torvalds if (len > size) 12291da177e4SLinus Torvalds len = size; 12301da177e4SLinus Torvalds if (skb_can_coalesce(skb, i, page, offset)) { 12311da177e4SLinus Torvalds skb_shinfo(skb)->frags[i-1].size += len; 12321da177e4SLinus Torvalds } else if (i < MAX_SKB_FRAGS) { 12331da177e4SLinus Torvalds get_page(page); 12341da177e4SLinus Torvalds skb_fill_page_desc(skb, i, page, offset, len); 12351da177e4SLinus Torvalds } else { 12361da177e4SLinus Torvalds err = -EMSGSIZE; 12371da177e4SLinus Torvalds goto error; 12381da177e4SLinus Torvalds } 12391da177e4SLinus Torvalds 12401da177e4SLinus Torvalds if (skb->ip_summed == CHECKSUM_NONE) { 124144bb9363SAl Viro __wsum csum; 12421da177e4SLinus Torvalds csum = csum_page(page, offset, len); 12431da177e4SLinus Torvalds skb->csum = csum_block_add(skb->csum, csum, skb->len); 12441da177e4SLinus Torvalds } 12451da177e4SLinus Torvalds 12461da177e4SLinus Torvalds skb->len += len; 12471da177e4SLinus Torvalds skb->data_len += len; 12481e34a11dSDavid S. Miller skb->truesize += len; 12491e34a11dSDavid S. Miller atomic_add(len, &sk->sk_wmem_alloc); 12501da177e4SLinus Torvalds offset += len; 12511da177e4SLinus Torvalds size -= len; 12521da177e4SLinus Torvalds } 12531da177e4SLinus Torvalds return 0; 12541da177e4SLinus Torvalds 12551da177e4SLinus Torvalds error: 1256bdc712b4SDavid S. Miller cork->length -= size; 12575e38e270SPavel Emelyanov IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); 12581da177e4SLinus Torvalds return err; 12591da177e4SLinus Torvalds } 12601da177e4SLinus Torvalds 12611470ddf7SHerbert Xu static void ip_cork_release(struct inet_cork *cork) 1262429f08e9SPavel Emelyanov { 12631470ddf7SHerbert Xu cork->flags &= ~IPCORK_OPT; 12641470ddf7SHerbert Xu kfree(cork->opt); 12651470ddf7SHerbert Xu cork->opt = NULL; 12661470ddf7SHerbert Xu dst_release(cork->dst); 12671470ddf7SHerbert Xu cork->dst = NULL; 1268429f08e9SPavel Emelyanov } 1269429f08e9SPavel Emelyanov 12701da177e4SLinus Torvalds /* 12711da177e4SLinus Torvalds * Combined all pending IP fragments on the socket as one IP datagram 12721da177e4SLinus Torvalds * and push them out. 12731da177e4SLinus Torvalds */ 12741c32c5adSHerbert Xu struct sk_buff *__ip_make_skb(struct sock *sk, 127577968b78SDavid S. Miller struct flowi4 *fl4, 12761470ddf7SHerbert Xu struct sk_buff_head *queue, 12771470ddf7SHerbert Xu struct inet_cork *cork) 12781da177e4SLinus Torvalds { 12791da177e4SLinus Torvalds struct sk_buff *skb, *tmp_skb; 12801da177e4SLinus Torvalds struct sk_buff **tail_skb; 12811da177e4SLinus Torvalds struct inet_sock *inet = inet_sk(sk); 12820388b004SPavel Emelyanov struct net *net = sock_net(sk); 12831da177e4SLinus Torvalds struct ip_options *opt = NULL; 12841470ddf7SHerbert Xu struct rtable *rt = (struct rtable *)cork->dst; 12851da177e4SLinus Torvalds struct iphdr *iph; 128676ab608dSAlexey Dobriyan __be16 df = 0; 12871da177e4SLinus Torvalds __u8 ttl; 12881da177e4SLinus Torvalds 12891470ddf7SHerbert Xu if ((skb = __skb_dequeue(queue)) == NULL) 12901da177e4SLinus Torvalds goto out; 12911da177e4SLinus Torvalds tail_skb = &(skb_shinfo(skb)->frag_list); 12921da177e4SLinus Torvalds 12931da177e4SLinus Torvalds /* move skb->data to ip header from ext header */ 1294d56f90a7SArnaldo Carvalho de Melo if (skb->data < skb_network_header(skb)) 1295bbe735e4SArnaldo Carvalho de Melo __skb_pull(skb, skb_network_offset(skb)); 12961470ddf7SHerbert Xu while ((tmp_skb = __skb_dequeue(queue)) != NULL) { 1297cfe1fc77SArnaldo Carvalho de Melo __skb_pull(tmp_skb, skb_network_header_len(skb)); 12981da177e4SLinus Torvalds *tail_skb = tmp_skb; 12991da177e4SLinus Torvalds tail_skb = &(tmp_skb->next); 13001da177e4SLinus Torvalds skb->len += tmp_skb->len; 13011da177e4SLinus Torvalds skb->data_len += tmp_skb->len; 13021da177e4SLinus Torvalds skb->truesize += tmp_skb->truesize; 13031da177e4SLinus Torvalds tmp_skb->destructor = NULL; 13041da177e4SLinus Torvalds tmp_skb->sk = NULL; 13051da177e4SLinus Torvalds } 13061da177e4SLinus Torvalds 13071da177e4SLinus Torvalds /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow 13081da177e4SLinus Torvalds * to fragment the frame generated here. No matter, what transforms 13091da177e4SLinus Torvalds * how transforms change size of the packet, it will come out. 13101da177e4SLinus Torvalds */ 1311628a5c56SJohn Heffner if (inet->pmtudisc < IP_PMTUDISC_DO) 13121da177e4SLinus Torvalds skb->local_df = 1; 13131da177e4SLinus Torvalds 13141da177e4SLinus Torvalds /* DF bit is set when we want to see DF on outgoing frames. 13151da177e4SLinus Torvalds * If local_df is set too, we still allow to fragment this frame 13161da177e4SLinus Torvalds * locally. */ 1317628a5c56SJohn Heffner if (inet->pmtudisc >= IP_PMTUDISC_DO || 1318d8d1f30bSChangli Gao (skb->len <= dst_mtu(&rt->dst) && 1319d8d1f30bSChangli Gao ip_dont_fragment(sk, &rt->dst))) 13201da177e4SLinus Torvalds df = htons(IP_DF); 13211da177e4SLinus Torvalds 13221470ddf7SHerbert Xu if (cork->flags & IPCORK_OPT) 13231470ddf7SHerbert Xu opt = cork->opt; 13241da177e4SLinus Torvalds 13251da177e4SLinus Torvalds if (rt->rt_type == RTN_MULTICAST) 13261da177e4SLinus Torvalds ttl = inet->mc_ttl; 13271da177e4SLinus Torvalds else 1328d8d1f30bSChangli Gao ttl = ip_select_ttl(inet, &rt->dst); 13291da177e4SLinus Torvalds 13301da177e4SLinus Torvalds iph = (struct iphdr *)skb->data; 13311da177e4SLinus Torvalds iph->version = 4; 13321da177e4SLinus Torvalds iph->ihl = 5; 13331da177e4SLinus Torvalds iph->tos = inet->tos; 13341da177e4SLinus Torvalds iph->frag_off = df; 1335d8d1f30bSChangli Gao ip_select_ident(iph, &rt->dst, sk); 13361da177e4SLinus Torvalds iph->ttl = ttl; 13371da177e4SLinus Torvalds iph->protocol = sk->sk_protocol; 133877968b78SDavid S. Miller iph->saddr = fl4->saddr; 133977968b78SDavid S. Miller iph->daddr = fl4->daddr; 13401da177e4SLinus Torvalds 134122f728f8SDavid S. Miller if (opt) { 134222f728f8SDavid S. Miller iph->ihl += opt->optlen>>2; 134322f728f8SDavid S. Miller ip_options_build(skb, opt, cork->addr, rt, 0); 134422f728f8SDavid S. Miller } 134522f728f8SDavid S. Miller 13461da177e4SLinus Torvalds skb->priority = sk->sk_priority; 13474a19ec58SLaszlo Attila Toth skb->mark = sk->sk_mark; 1348a21bba94SEric Dumazet /* 1349a21bba94SEric Dumazet * Steal rt from cork.dst to avoid a pair of atomic_inc/atomic_dec 1350a21bba94SEric Dumazet * on dst refcount 1351a21bba94SEric Dumazet */ 13521470ddf7SHerbert Xu cork->dst = NULL; 1353d8d1f30bSChangli Gao skb_dst_set(skb, &rt->dst); 13541da177e4SLinus Torvalds 135596793b48SDavid L Stevens if (iph->protocol == IPPROTO_ICMP) 13560388b004SPavel Emelyanov icmp_out_count(net, ((struct icmphdr *) 135796793b48SDavid L Stevens skb_transport_header(skb))->type); 135896793b48SDavid L Stevens 13591c32c5adSHerbert Xu ip_cork_release(cork); 13601c32c5adSHerbert Xu out: 13611c32c5adSHerbert Xu return skb; 13621c32c5adSHerbert Xu } 13631c32c5adSHerbert Xu 13641c32c5adSHerbert Xu int ip_send_skb(struct sk_buff *skb) 13651c32c5adSHerbert Xu { 13661c32c5adSHerbert Xu struct net *net = sock_net(skb->sk); 13671c32c5adSHerbert Xu int err; 13681c32c5adSHerbert Xu 1369c439cb2eSHerbert Xu err = ip_local_out(skb); 13701da177e4SLinus Torvalds if (err) { 13711da177e4SLinus Torvalds if (err > 0) 13726ce9e7b5SEric Dumazet err = net_xmit_errno(err); 13731da177e4SLinus Torvalds if (err) 13741c32c5adSHerbert Xu IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS); 13751da177e4SLinus Torvalds } 13761da177e4SLinus Torvalds 13771da177e4SLinus Torvalds return err; 13781da177e4SLinus Torvalds } 13791da177e4SLinus Torvalds 138077968b78SDavid S. Miller int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4) 13811470ddf7SHerbert Xu { 13821c32c5adSHerbert Xu struct sk_buff *skb; 13831c32c5adSHerbert Xu 138477968b78SDavid S. Miller skb = ip_finish_skb(sk, fl4); 13851c32c5adSHerbert Xu if (!skb) 13861c32c5adSHerbert Xu return 0; 13871c32c5adSHerbert Xu 13881c32c5adSHerbert Xu /* Netfilter gets whole the not fragmented skb. */ 13891c32c5adSHerbert Xu return ip_send_skb(skb); 13901470ddf7SHerbert Xu } 13911470ddf7SHerbert Xu 13921da177e4SLinus Torvalds /* 13931da177e4SLinus Torvalds * Throw away all pending data on the socket. 13941da177e4SLinus Torvalds */ 13951470ddf7SHerbert Xu static void __ip_flush_pending_frames(struct sock *sk, 13961470ddf7SHerbert Xu struct sk_buff_head *queue, 13971470ddf7SHerbert Xu struct inet_cork *cork) 13981da177e4SLinus Torvalds { 13991da177e4SLinus Torvalds struct sk_buff *skb; 14001da177e4SLinus Torvalds 14011470ddf7SHerbert Xu while ((skb = __skb_dequeue_tail(queue)) != NULL) 14021da177e4SLinus Torvalds kfree_skb(skb); 14031da177e4SLinus Torvalds 14041470ddf7SHerbert Xu ip_cork_release(cork); 14051470ddf7SHerbert Xu } 14061470ddf7SHerbert Xu 14071470ddf7SHerbert Xu void ip_flush_pending_frames(struct sock *sk) 14081470ddf7SHerbert Xu { 1409bdc712b4SDavid S. Miller __ip_flush_pending_frames(sk, &sk->sk_write_queue, &inet_sk(sk)->cork.base); 14101da177e4SLinus Torvalds } 14111da177e4SLinus Torvalds 14121c32c5adSHerbert Xu struct sk_buff *ip_make_skb(struct sock *sk, 141377968b78SDavid S. Miller struct flowi4 *fl4, 14141c32c5adSHerbert Xu int getfrag(void *from, char *to, int offset, 14151c32c5adSHerbert Xu int len, int odd, struct sk_buff *skb), 14161c32c5adSHerbert Xu void *from, int length, int transhdrlen, 14171c32c5adSHerbert Xu struct ipcm_cookie *ipc, struct rtable **rtp, 14181c32c5adSHerbert Xu unsigned int flags) 14191c32c5adSHerbert Xu { 1420b80d7226SDavid S. Miller struct inet_cork cork; 14211c32c5adSHerbert Xu struct sk_buff_head queue; 14221c32c5adSHerbert Xu int err; 14231c32c5adSHerbert Xu 14241c32c5adSHerbert Xu if (flags & MSG_PROBE) 14251c32c5adSHerbert Xu return NULL; 14261c32c5adSHerbert Xu 14271c32c5adSHerbert Xu __skb_queue_head_init(&queue); 14281c32c5adSHerbert Xu 1429b80d7226SDavid S. Miller cork.flags = 0; 1430b80d7226SDavid S. Miller cork.addr = 0; 143170652728SDavid S. Miller cork.opt = NULL; 14321c32c5adSHerbert Xu err = ip_setup_cork(sk, &cork, ipc, rtp); 14331c32c5adSHerbert Xu if (err) 14341c32c5adSHerbert Xu return ERR_PTR(err); 14351c32c5adSHerbert Xu 1436f5fca608SDavid S. Miller err = __ip_append_data(sk, fl4, &queue, &cork, getfrag, 14371c32c5adSHerbert Xu from, length, transhdrlen, flags); 14381c32c5adSHerbert Xu if (err) { 14391c32c5adSHerbert Xu __ip_flush_pending_frames(sk, &queue, &cork); 14401c32c5adSHerbert Xu return ERR_PTR(err); 14411c32c5adSHerbert Xu } 14421c32c5adSHerbert Xu 144377968b78SDavid S. Miller return __ip_make_skb(sk, fl4, &queue, &cork); 14441c32c5adSHerbert Xu } 14451da177e4SLinus Torvalds 14461da177e4SLinus Torvalds /* 14471da177e4SLinus Torvalds * Fetch data from kernel space and fill in checksum if needed. 14481da177e4SLinus Torvalds */ 14491da177e4SLinus Torvalds static int ip_reply_glue_bits(void *dptr, char *to, int offset, 14501da177e4SLinus Torvalds int len, int odd, struct sk_buff *skb) 14511da177e4SLinus Torvalds { 14525084205fSAl Viro __wsum csum; 14531da177e4SLinus Torvalds 14541da177e4SLinus Torvalds csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); 14551da177e4SLinus Torvalds skb->csum = csum_block_add(skb->csum, csum, odd); 14561da177e4SLinus Torvalds return 0; 14571da177e4SLinus Torvalds } 14581da177e4SLinus Torvalds 14591da177e4SLinus Torvalds /* 14601da177e4SLinus Torvalds * Generic function to send a packet as reply to another packet. 14611da177e4SLinus Torvalds * Used to send TCP resets so far. ICMP should use this function too. 14621da177e4SLinus Torvalds * 14631da177e4SLinus Torvalds * Should run single threaded per socket because it uses the sock 14641da177e4SLinus Torvalds * structure to pass arguments. 14651da177e4SLinus Torvalds */ 14660a5ebb80SDavid S. Miller void ip_send_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr, 14670a5ebb80SDavid S. Miller struct ip_reply_arg *arg, unsigned int len) 14681da177e4SLinus Torvalds { 14691da177e4SLinus Torvalds struct inet_sock *inet = inet_sk(sk); 1470f6d8bd05SEric Dumazet struct ip_options_data replyopts; 14711da177e4SLinus Torvalds struct ipcm_cookie ipc; 147277968b78SDavid S. Miller struct flowi4 fl4; 1473511c3f92SEric Dumazet struct rtable *rt = skb_rtable(skb); 14741da177e4SLinus Torvalds 1475f6d8bd05SEric Dumazet if (ip_options_echo(&replyopts.opt.opt, skb)) 14761da177e4SLinus Torvalds return; 14771da177e4SLinus Torvalds 14780a5ebb80SDavid S. Miller ipc.addr = daddr; 14791da177e4SLinus Torvalds ipc.opt = NULL; 14802244d07bSOliver Hartkopp ipc.tx_flags = 0; 14811da177e4SLinus Torvalds 1482f6d8bd05SEric Dumazet if (replyopts.opt.opt.optlen) { 14831da177e4SLinus Torvalds ipc.opt = &replyopts.opt; 14841da177e4SLinus Torvalds 1485f6d8bd05SEric Dumazet if (replyopts.opt.opt.srr) 1486f6d8bd05SEric Dumazet daddr = replyopts.opt.opt.faddr; 14871da177e4SLinus Torvalds } 14881da177e4SLinus Torvalds 1489538de0e0SDavid S. Miller flowi4_init_output(&fl4, arg->bound_dev_if, 0, 1490538de0e0SDavid S. Miller RT_TOS(ip_hdr(skb)->tos), 1491538de0e0SDavid S. Miller RT_SCOPE_UNIVERSE, sk->sk_protocol, 1492538de0e0SDavid S. Miller ip_reply_arg_flowi_flags(arg), 1493538de0e0SDavid S. Miller daddr, rt->rt_spec_dst, 1494538de0e0SDavid S. Miller tcp_hdr(skb)->source, tcp_hdr(skb)->dest); 14959d6ec938SDavid S. Miller security_skb_classify_flow(skb, flowi4_to_flowi(&fl4)); 14969d6ec938SDavid S. Miller rt = ip_route_output_key(sock_net(sk), &fl4); 1497b23dd4feSDavid S. Miller if (IS_ERR(rt)) 14981da177e4SLinus Torvalds return; 14991da177e4SLinus Torvalds 15001da177e4SLinus Torvalds /* And let IP do all the hard work. 15011da177e4SLinus Torvalds 15021da177e4SLinus Torvalds This chunk is not reenterable, hence spinlock. 15031da177e4SLinus Torvalds Note that it uses the fact, that this function is called 15041da177e4SLinus Torvalds with locally disabled BH and that sk cannot be already spinlocked. 15051da177e4SLinus Torvalds */ 15061da177e4SLinus Torvalds bh_lock_sock(sk); 1507eddc9ec5SArnaldo Carvalho de Melo inet->tos = ip_hdr(skb)->tos; 15081da177e4SLinus Torvalds sk->sk_priority = skb->priority; 1509eddc9ec5SArnaldo Carvalho de Melo sk->sk_protocol = ip_hdr(skb)->protocol; 1510f0e48dbfSPatrick McHardy sk->sk_bound_dev_if = arg->bound_dev_if; 1511f5fca608SDavid S. Miller ip_append_data(sk, &fl4, ip_reply_glue_bits, arg->iov->iov_base, len, 0, 15122e77d89bSEric Dumazet &ipc, &rt, MSG_DONTWAIT); 15131da177e4SLinus Torvalds if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { 15141da177e4SLinus Torvalds if (arg->csumoffset >= 0) 15159c70220bSArnaldo Carvalho de Melo *((__sum16 *)skb_transport_header(skb) + 15169c70220bSArnaldo Carvalho de Melo arg->csumoffset) = csum_fold(csum_add(skb->csum, 15179c70220bSArnaldo Carvalho de Melo arg->csum)); 15181da177e4SLinus Torvalds skb->ip_summed = CHECKSUM_NONE; 151977968b78SDavid S. Miller ip_push_pending_frames(sk, &fl4); 15201da177e4SLinus Torvalds } 15211da177e4SLinus Torvalds 15221da177e4SLinus Torvalds bh_unlock_sock(sk); 15231da177e4SLinus Torvalds 15241da177e4SLinus Torvalds ip_rt_put(rt); 15251da177e4SLinus Torvalds } 15261da177e4SLinus Torvalds 15271da177e4SLinus Torvalds void __init ip_init(void) 15281da177e4SLinus Torvalds { 15291da177e4SLinus Torvalds ip_rt_init(); 15301da177e4SLinus Torvalds inet_initpeers(); 15311da177e4SLinus Torvalds 15321da177e4SLinus Torvalds #if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS) 15331da177e4SLinus Torvalds igmp_mc_proc_init(); 15341da177e4SLinus Torvalds #endif 15351da177e4SLinus Torvalds } 1536