Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * INET An implementation of the TCP/IP protocol suite for the LINUX |
| 3 | * operating system. INET is implemented using the BSD Socket |
| 4 | * interface as the means of communication with the user level. |
| 5 | * |
| 6 | * The Internet Protocol (IP) output module. |
| 7 | * |
Jesper Juhl | 02c30a8 | 2005-05-05 16:16:16 -0700 | [diff] [blame] | 8 | * Authors: Ross Biro |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
| 10 | * Donald Becker, <becker@super.org> |
| 11 | * Alan Cox, <Alan.Cox@linux.org> |
| 12 | * Richard Underwood |
| 13 | * Stefan Becker, <stefanb@yello.ping.de> |
| 14 | * Jorge Cwik, <jorge@laser.satlink.net> |
| 15 | * Arnt Gulbrandsen, <agulbra@nvg.unit.no> |
| 16 | * Hirokazu Takahashi, <taka@valinux.co.jp> |
| 17 | * |
| 18 | * See ip_input.c for original log |
| 19 | * |
| 20 | * Fixes: |
| 21 | * Alan Cox : Missing nonblock feature in ip_build_xmit. |
| 22 | * Mike Kilburn : htons() missing in ip_build_xmit. |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 23 | * Bradford Johnson: Fix faulty handling of some frames when |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | * no route is found. |
| 25 | * Alexander Demenshin: Missing sk/skb free in ip_queue_xmit |
| 26 | * (in case if packet not accepted by |
| 27 | * output firewall rules) |
| 28 | * Mike McLagan : Routing by source |
| 29 | * Alexey Kuznetsov: use new route cache |
| 30 | * Andi Kleen: Fix broken PMTU recovery and remove |
| 31 | * some redundant tests. |
| 32 | * Vitaly E. Lavrov : Transparent proxy revived after year coma. |
| 33 | * Andi Kleen : Replace ip_reply with ip_send_reply. |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 34 | * Andi Kleen : Split fast and slow ip_build_xmit path |
| 35 | * for decreased register pressure on x86 |
| 36 | * and more readibility. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | * Marc Boucher : When call_out_firewall returns FW_QUEUE, |
| 38 | * silently drop skb instead of failing with -EPERM. |
| 39 | * Detlev Wengorz : Copy protocol for fragments. |
| 40 | * Hirokazu Takahashi: HW checksumming for outgoing UDP |
| 41 | * datagrams. |
| 42 | * Hirokazu Takahashi: sendfile() on UDP works now. |
| 43 | */ |
| 44 | |
| 45 | #include <asm/uaccess.h> |
| 46 | #include <asm/system.h> |
| 47 | #include <linux/module.h> |
| 48 | #include <linux/types.h> |
| 49 | #include <linux/kernel.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | #include <linux/mm.h> |
| 51 | #include <linux/string.h> |
| 52 | #include <linux/errno.h> |
Al Viro | a1f8e7f7 | 2006-10-19 16:08:53 -0400 | [diff] [blame] | 53 | #include <linux/highmem.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | |
| 55 | #include <linux/socket.h> |
| 56 | #include <linux/sockios.h> |
| 57 | #include <linux/in.h> |
| 58 | #include <linux/inet.h> |
| 59 | #include <linux/netdevice.h> |
| 60 | #include <linux/etherdevice.h> |
| 61 | #include <linux/proc_fs.h> |
| 62 | #include <linux/stat.h> |
| 63 | #include <linux/init.h> |
| 64 | |
| 65 | #include <net/snmp.h> |
| 66 | #include <net/ip.h> |
| 67 | #include <net/protocol.h> |
| 68 | #include <net/route.h> |
Patrick McHardy | cfacb05 | 2006-01-08 22:36:54 -0800 | [diff] [blame] | 69 | #include <net/xfrm.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | #include <linux/skbuff.h> |
| 71 | #include <net/sock.h> |
| 72 | #include <net/arp.h> |
| 73 | #include <net/icmp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | #include <net/checksum.h> |
| 75 | #include <net/inetpeer.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | #include <linux/igmp.h> |
| 77 | #include <linux/netfilter_ipv4.h> |
| 78 | #include <linux/netfilter_bridge.h> |
| 79 | #include <linux/mroute.h> |
| 80 | #include <linux/netlink.h> |
Arnaldo Carvalho de Melo | 6cbb0df | 2005-08-09 19:49:02 -0700 | [diff] [blame] | 81 | #include <linux/tcp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | |
Brian Haley | ab32ea5 | 2006-09-22 14:15:41 -0700 | [diff] [blame] | 83 | int sysctl_ip_default_ttl __read_mostly = IPDEFTTL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | |
| 85 | /* Generate a checksum for an outgoing IP datagram. */ |
| 86 | __inline__ void ip_send_check(struct iphdr *iph) |
| 87 | { |
| 88 | iph->check = 0; |
| 89 | iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); |
| 90 | } |
| 91 | |
Herbert Xu | c439cb2 | 2008-01-11 19:14:00 -0800 | [diff] [blame] | 92 | int __ip_local_out(struct sk_buff *skb) |
| 93 | { |
| 94 | struct iphdr *iph = ip_hdr(skb); |
| 95 | |
| 96 | iph->tot_len = htons(skb->len); |
| 97 | ip_send_check(iph); |
Eric Dumazet | adf3090 | 2009-06-02 05:19:30 +0000 | [diff] [blame] | 98 | return nf_hook(PF_INET, NF_INET_LOCAL_OUT, skb, NULL, skb_dst(skb)->dev, |
Herbert Xu | c439cb2 | 2008-01-11 19:14:00 -0800 | [diff] [blame] | 99 | dst_output); |
| 100 | } |
| 101 | |
| 102 | int ip_local_out(struct sk_buff *skb) |
| 103 | { |
| 104 | int err; |
| 105 | |
| 106 | err = __ip_local_out(skb); |
| 107 | if (likely(err == 1)) |
| 108 | err = dst_output(skb); |
| 109 | |
| 110 | return err; |
| 111 | } |
| 112 | EXPORT_SYMBOL_GPL(ip_local_out); |
| 113 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | /* dev_loopback_xmit for use with netfilter. */ |
| 115 | static int ip_dev_loopback_xmit(struct sk_buff *newskb) |
| 116 | { |
Arnaldo Carvalho de Melo | 459a98e | 2007-03-19 15:30:44 -0700 | [diff] [blame] | 117 | skb_reset_mac_header(newskb); |
Arnaldo Carvalho de Melo | bbe735e | 2007-03-10 22:16:10 -0300 | [diff] [blame] | 118 | __skb_pull(newskb, skb_network_offset(newskb)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | newskb->pkt_type = PACKET_LOOPBACK; |
| 120 | newskb->ip_summed = CHECKSUM_UNNECESSARY; |
Eric Dumazet | adf3090 | 2009-06-02 05:19:30 +0000 | [diff] [blame] | 121 | WARN_ON(!skb_dst(newskb)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | netif_rx(newskb); |
| 123 | return 0; |
| 124 | } |
| 125 | |
| 126 | static inline int ip_select_ttl(struct inet_sock *inet, struct dst_entry *dst) |
| 127 | { |
| 128 | int ttl = inet->uc_ttl; |
| 129 | |
| 130 | if (ttl < 0) |
| 131 | ttl = dst_metric(dst, RTAX_HOPLIMIT); |
| 132 | return ttl; |
| 133 | } |
| 134 | |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 135 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | * Add an ip header to a skbuff and send it out. |
| 137 | * |
| 138 | */ |
| 139 | int ip_build_and_send_pkt(struct sk_buff *skb, struct sock *sk, |
Al Viro | 13d8eaa | 2006-09-26 22:27:30 -0700 | [diff] [blame] | 140 | __be32 saddr, __be32 daddr, struct ip_options *opt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | { |
| 142 | struct inet_sock *inet = inet_sk(sk); |
Eric Dumazet | 511c3f9 | 2009-06-02 05:14:27 +0000 | [diff] [blame] | 143 | struct rtable *rt = skb_rtable(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | struct iphdr *iph; |
| 145 | |
| 146 | /* Build the IP header. */ |
Arnaldo Carvalho de Melo | 8856dfa | 2007-03-10 19:40:39 -0300 | [diff] [blame] | 147 | skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); |
| 148 | skb_reset_network_header(skb); |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 149 | iph = ip_hdr(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | iph->version = 4; |
| 151 | iph->ihl = 5; |
| 152 | iph->tos = inet->tos; |
| 153 | if (ip_dont_fragment(sk, &rt->u.dst)) |
| 154 | iph->frag_off = htons(IP_DF); |
| 155 | else |
| 156 | iph->frag_off = 0; |
| 157 | iph->ttl = ip_select_ttl(inet, &rt->u.dst); |
| 158 | iph->daddr = rt->rt_dst; |
| 159 | iph->saddr = rt->rt_src; |
| 160 | iph->protocol = sk->sk_protocol; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | ip_select_ident(iph, &rt->u.dst, sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | |
| 163 | if (opt && opt->optlen) { |
| 164 | iph->ihl += opt->optlen>>2; |
| 165 | ip_options_build(skb, opt, daddr, rt, 0); |
| 166 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | |
| 168 | skb->priority = sk->sk_priority; |
Laszlo Attila Toth | 4a19ec5 | 2008-01-30 19:08:16 -0800 | [diff] [blame] | 169 | skb->mark = sk->sk_mark; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | |
| 171 | /* Send it out. */ |
Herbert Xu | c439cb2 | 2008-01-11 19:14:00 -0800 | [diff] [blame] | 172 | return ip_local_out(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | } |
| 174 | |
Arnaldo Carvalho de Melo | d8c97a9 | 2005-08-09 20:12:12 -0700 | [diff] [blame] | 175 | EXPORT_SYMBOL_GPL(ip_build_and_send_pkt); |
| 176 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | static inline int ip_finish_output2(struct sk_buff *skb) |
| 178 | { |
Eric Dumazet | adf3090 | 2009-06-02 05:19:30 +0000 | [diff] [blame] | 179 | struct dst_entry *dst = skb_dst(skb); |
Mitsuru Chinen | 80787eb | 2007-04-30 00:48:20 -0700 | [diff] [blame] | 180 | struct rtable *rt = (struct rtable *)dst; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | struct net_device *dev = dst->dev; |
Chuck Lever | c2636b4 | 2007-10-23 21:07:32 -0700 | [diff] [blame] | 182 | unsigned int hh_len = LL_RESERVED_SPACE(dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | |
Neil Horman | edf391f | 2009-04-27 02:45:02 -0700 | [diff] [blame] | 184 | if (rt->rt_type == RTN_MULTICAST) { |
| 185 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTMCAST, skb->len); |
| 186 | } else if (rt->rt_type == RTN_BROADCAST) |
| 187 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUTBCAST, skb->len); |
Mitsuru Chinen | 80787eb | 2007-04-30 00:48:20 -0700 | [diff] [blame] | 188 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | /* Be paranoid, rather than too clever. */ |
Stephen Hemminger | 3b04ddd | 2007-10-09 01:40:57 -0700 | [diff] [blame] | 190 | if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | struct sk_buff *skb2; |
| 192 | |
| 193 | skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); |
| 194 | if (skb2 == NULL) { |
| 195 | kfree_skb(skb); |
| 196 | return -ENOMEM; |
| 197 | } |
| 198 | if (skb->sk) |
| 199 | skb_set_owner_w(skb2, skb->sk); |
| 200 | kfree_skb(skb); |
| 201 | skb = skb2; |
| 202 | } |
| 203 | |
Stephen Hemminger | 3644f0c | 2006-12-07 15:08:17 -0800 | [diff] [blame] | 204 | if (dst->hh) |
| 205 | return neigh_hh_output(dst->hh, skb); |
| 206 | else if (dst->neighbour) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | return dst->neighbour->output(skb); |
| 208 | |
| 209 | if (net_ratelimit()) |
| 210 | printk(KERN_DEBUG "ip_finish_output2: No header cache and no neighbour!\n"); |
| 211 | kfree_skb(skb); |
| 212 | return -EINVAL; |
| 213 | } |
| 214 | |
John Heffner | 628a5c5 | 2007-04-20 15:53:27 -0700 | [diff] [blame] | 215 | static inline int ip_skb_dst_mtu(struct sk_buff *skb) |
| 216 | { |
| 217 | struct inet_sock *inet = skb->sk ? inet_sk(skb->sk) : NULL; |
| 218 | |
| 219 | return (inet && inet->pmtudisc == IP_PMTUDISC_PROBE) ? |
Eric Dumazet | adf3090 | 2009-06-02 05:19:30 +0000 | [diff] [blame] | 220 | skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); |
John Heffner | 628a5c5 | 2007-04-20 15:53:27 -0700 | [diff] [blame] | 221 | } |
| 222 | |
Patrick McHardy | 861d048 | 2007-10-15 01:48:39 -0700 | [diff] [blame] | 223 | static int ip_finish_output(struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | { |
Patrick McHardy | 5c901da | 2006-01-06 23:05:36 -0800 | [diff] [blame] | 225 | #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) |
| 226 | /* Policy lookup after SNAT yielded a new policy */ |
Eric Dumazet | adf3090 | 2009-06-02 05:19:30 +0000 | [diff] [blame] | 227 | if (skb_dst(skb)->xfrm != NULL) { |
Patrick McHardy | 48d5cad | 2006-02-15 15:10:22 -0800 | [diff] [blame] | 228 | IPCB(skb)->flags |= IPSKB_REROUTED; |
| 229 | return dst_output(skb); |
| 230 | } |
Patrick McHardy | 5c901da | 2006-01-06 23:05:36 -0800 | [diff] [blame] | 231 | #endif |
John Heffner | 628a5c5 | 2007-04-20 15:53:27 -0700 | [diff] [blame] | 232 | if (skb->len > ip_skb_dst_mtu(skb) && !skb_is_gso(skb)) |
Patrick McHardy | 1bd9bef | 2006-01-05 12:20:59 -0800 | [diff] [blame] | 233 | return ip_fragment(skb, ip_finish_output2); |
| 234 | else |
| 235 | return ip_finish_output2(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | } |
| 237 | |
| 238 | int ip_mc_output(struct sk_buff *skb) |
| 239 | { |
| 240 | struct sock *sk = skb->sk; |
Eric Dumazet | 511c3f9 | 2009-06-02 05:14:27 +0000 | [diff] [blame] | 241 | struct rtable *rt = skb_rtable(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | struct net_device *dev = rt->u.dst.dev; |
| 243 | |
| 244 | /* |
| 245 | * If the indicated interface is up and running, send the packet. |
| 246 | */ |
Neil Horman | edf391f | 2009-04-27 02:45:02 -0700 | [diff] [blame] | 247 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | |
| 249 | skb->dev = dev; |
| 250 | skb->protocol = htons(ETH_P_IP); |
| 251 | |
| 252 | /* |
| 253 | * Multicasts are looped back for other local users |
| 254 | */ |
| 255 | |
| 256 | if (rt->rt_flags&RTCF_MULTICAST) { |
| 257 | if ((!sk || inet_sk(sk)->mc_loop) |
| 258 | #ifdef CONFIG_IP_MROUTE |
| 259 | /* Small optimization: do not loopback not local frames, |
| 260 | which returned after forwarding; they will be dropped |
| 261 | by ip_mr_input in any case. |
| 262 | Note, that local frames are looped back to be delivered |
| 263 | to local recipients. |
| 264 | |
| 265 | This check is duplicated in ip_mr_input at the moment. |
| 266 | */ |
| 267 | && ((rt->rt_flags&RTCF_LOCAL) || !(IPCB(skb)->flags&IPSKB_FORWARDED)) |
| 268 | #endif |
| 269 | ) { |
| 270 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); |
| 271 | if (newskb) |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 272 | NF_HOOK(PF_INET, NF_INET_POST_ROUTING, newskb, |
| 273 | NULL, newskb->dev, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | ip_dev_loopback_xmit); |
| 275 | } |
| 276 | |
| 277 | /* Multicasts with ttl 0 must not go beyond the host */ |
| 278 | |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 279 | if (ip_hdr(skb)->ttl == 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | kfree_skb(skb); |
| 281 | return 0; |
| 282 | } |
| 283 | } |
| 284 | |
| 285 | if (rt->rt_flags&RTCF_BROADCAST) { |
| 286 | struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); |
| 287 | if (newskb) |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 288 | NF_HOOK(PF_INET, NF_INET_POST_ROUTING, newskb, NULL, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | newskb->dev, ip_dev_loopback_xmit); |
| 290 | } |
| 291 | |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 292 | return NF_HOOK_COND(PF_INET, NF_INET_POST_ROUTING, skb, NULL, skb->dev, |
Patrick McHardy | 48d5cad | 2006-02-15 15:10:22 -0800 | [diff] [blame] | 293 | ip_finish_output, |
| 294 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | } |
| 296 | |
| 297 | int ip_output(struct sk_buff *skb) |
| 298 | { |
Eric Dumazet | adf3090 | 2009-06-02 05:19:30 +0000 | [diff] [blame] | 299 | struct net_device *dev = skb_dst(skb)->dev; |
Patrick McHardy | 1bd9bef | 2006-01-05 12:20:59 -0800 | [diff] [blame] | 300 | |
Neil Horman | edf391f | 2009-04-27 02:45:02 -0700 | [diff] [blame] | 301 | IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | |
Patrick McHardy | 1bd9bef | 2006-01-05 12:20:59 -0800 | [diff] [blame] | 303 | skb->dev = dev; |
| 304 | skb->protocol = htons(ETH_P_IP); |
| 305 | |
Patrick McHardy | 6e23ae2 | 2007-11-19 18:53:30 -0800 | [diff] [blame] | 306 | return NF_HOOK_COND(PF_INET, NF_INET_POST_ROUTING, skb, NULL, dev, |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 307 | ip_finish_output, |
Patrick McHardy | 48d5cad | 2006-02-15 15:10:22 -0800 | [diff] [blame] | 308 | !(IPCB(skb)->flags & IPSKB_REROUTED)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | } |
| 310 | |
David S. Miller | e89862f | 2007-01-26 01:04:55 -0800 | [diff] [blame] | 311 | int ip_queue_xmit(struct sk_buff *skb, int ipfragok) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | { |
David S. Miller | e89862f | 2007-01-26 01:04:55 -0800 | [diff] [blame] | 313 | struct sock *sk = skb->sk; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | struct inet_sock *inet = inet_sk(sk); |
| 315 | struct ip_options *opt = inet->opt; |
| 316 | struct rtable *rt; |
| 317 | struct iphdr *iph; |
| 318 | |
| 319 | /* Skip all of this if the packet is already routed, |
| 320 | * f.e. by something like SCTP. |
| 321 | */ |
Eric Dumazet | 511c3f9 | 2009-06-02 05:14:27 +0000 | [diff] [blame] | 322 | rt = skb_rtable(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | if (rt != NULL) |
| 324 | goto packet_routed; |
| 325 | |
| 326 | /* Make sure we can route this packet. */ |
| 327 | rt = (struct rtable *)__sk_dst_check(sk, 0); |
| 328 | if (rt == NULL) { |
Al Viro | 3ca3c68 | 2006-09-27 18:28:07 -0700 | [diff] [blame] | 329 | __be32 daddr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 330 | |
| 331 | /* Use correct destination address if we have options. */ |
| 332 | daddr = inet->daddr; |
| 333 | if(opt && opt->srr) |
| 334 | daddr = opt->faddr; |
| 335 | |
| 336 | { |
| 337 | struct flowi fl = { .oif = sk->sk_bound_dev_if, |
Atis Elsts | 914a9ab | 2009-10-01 15:16:49 -0700 | [diff] [blame] | 338 | .mark = sk->sk_mark, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 339 | .nl_u = { .ip4_u = |
| 340 | { .daddr = daddr, |
| 341 | .saddr = inet->saddr, |
| 342 | .tos = RT_CONN_FLAGS(sk) } }, |
| 343 | .proto = sk->sk_protocol, |
KOVACS Krisztian | 86b08d8 | 2008-10-01 07:44:42 -0700 | [diff] [blame] | 344 | .flags = inet_sk_flowi_flags(sk), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 345 | .uli_u = { .ports = |
| 346 | { .sport = inet->sport, |
| 347 | .dport = inet->dport } } }; |
| 348 | |
| 349 | /* If this fails, retransmit mechanism of transport layer will |
| 350 | * keep trying until route appears or the connection times |
| 351 | * itself out. |
| 352 | */ |
Venkat Yekkirala | beb8d13 | 2006-08-04 23:12:42 -0700 | [diff] [blame] | 353 | security_sk_classify_flow(sk, &fl); |
YOSHIFUJI Hideaki | 3b1e0a6 | 2008-03-26 02:26:21 +0900 | [diff] [blame] | 354 | if (ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 355 | goto no_route; |
| 356 | } |
Arnaldo Carvalho de Melo | 6cbb0df | 2005-08-09 19:49:02 -0700 | [diff] [blame] | 357 | sk_setup_caps(sk, &rt->u.dst); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | } |
Eric Dumazet | adf3090 | 2009-06-02 05:19:30 +0000 | [diff] [blame] | 359 | skb_dst_set(skb, dst_clone(&rt->u.dst)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 360 | |
| 361 | packet_routed: |
| 362 | if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) |
| 363 | goto no_route; |
| 364 | |
| 365 | /* OK, we know where to send it, allocate and build IP header. */ |
Arnaldo Carvalho de Melo | 8856dfa | 2007-03-10 19:40:39 -0300 | [diff] [blame] | 366 | skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0)); |
| 367 | skb_reset_network_header(skb); |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 368 | iph = ip_hdr(skb); |
Al Viro | 714e85b | 2006-11-14 20:51:49 -0800 | [diff] [blame] | 369 | *((__be16 *)iph) = htons((4 << 12) | (5 << 8) | (inet->tos & 0xff)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 370 | if (ip_dont_fragment(sk, &rt->u.dst) && !ipfragok) |
| 371 | iph->frag_off = htons(IP_DF); |
| 372 | else |
| 373 | iph->frag_off = 0; |
| 374 | iph->ttl = ip_select_ttl(inet, &rt->u.dst); |
| 375 | iph->protocol = sk->sk_protocol; |
| 376 | iph->saddr = rt->rt_src; |
| 377 | iph->daddr = rt->rt_dst; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 378 | /* Transport layer set skb->h.foo itself. */ |
| 379 | |
| 380 | if (opt && opt->optlen) { |
| 381 | iph->ihl += opt->optlen >> 2; |
| 382 | ip_options_build(skb, opt, inet->daddr, rt, 0); |
| 383 | } |
| 384 | |
Herbert Xu | 89f5f0a | 2005-11-08 09:41:56 -0800 | [diff] [blame] | 385 | ip_select_ident_more(iph, &rt->u.dst, sk, |
Herbert Xu | 7967168 | 2006-06-22 02:40:14 -0700 | [diff] [blame] | 386 | (skb_shinfo(skb)->gso_segs ?: 1) - 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | skb->priority = sk->sk_priority; |
Laszlo Attila Toth | 4a19ec5 | 2008-01-30 19:08:16 -0800 | [diff] [blame] | 389 | skb->mark = sk->sk_mark; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | |
Herbert Xu | c439cb2 | 2008-01-11 19:14:00 -0800 | [diff] [blame] | 391 | return ip_local_out(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | |
| 393 | no_route: |
Pavel Emelyanov | 5e38e27 | 2008-07-16 20:19:49 -0700 | [diff] [blame] | 394 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 395 | kfree_skb(skb); |
| 396 | return -EHOSTUNREACH; |
| 397 | } |
| 398 | |
| 399 | |
| 400 | static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) |
| 401 | { |
| 402 | to->pkt_type = from->pkt_type; |
| 403 | to->priority = from->priority; |
| 404 | to->protocol = from->protocol; |
Eric Dumazet | adf3090 | 2009-06-02 05:19:30 +0000 | [diff] [blame] | 405 | skb_dst_drop(to); |
| 406 | skb_dst_set(to, dst_clone(skb_dst(from))); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 407 | to->dev = from->dev; |
Thomas Graf | 82e91ff | 2006-11-09 15:19:14 -0800 | [diff] [blame] | 408 | to->mark = from->mark; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | |
| 410 | /* Copy the flags to each fragment. */ |
| 411 | IPCB(to)->flags = IPCB(from)->flags; |
| 412 | |
| 413 | #ifdef CONFIG_NET_SCHED |
| 414 | to->tc_index = from->tc_index; |
| 415 | #endif |
Yasuyuki Kozakai | e7ac05f | 2007-03-14 16:44:01 -0700 | [diff] [blame] | 416 | nf_copy(to, from); |
Jozsef Kadlecsik | ba9dda3 | 2007-07-07 22:21:23 -0700 | [diff] [blame] | 417 | #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \ |
| 418 | defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE) |
| 419 | to->nf_trace = from->nf_trace; |
| 420 | #endif |
Julian Anastasov | c98d80e | 2005-10-22 13:39:21 +0300 | [diff] [blame] | 421 | #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) |
| 422 | to->ipvs_property = from->ipvs_property; |
| 423 | #endif |
James Morris | 984bc16 | 2006-06-09 00:29:17 -0700 | [diff] [blame] | 424 | skb_copy_secmark(to, from); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 425 | } |
| 426 | |
| 427 | /* |
| 428 | * This IP datagram is too large to be sent in one piece. Break it up into |
| 429 | * smaller pieces (each of size equal to IP header plus |
| 430 | * a block of the data of the original IP data part) that will yet fit in a |
| 431 | * single device frame, and queue such a frame for sending. |
| 432 | */ |
| 433 | |
Jianjun Kong | d9319100 | 2008-11-03 00:23:42 -0800 | [diff] [blame] | 434 | int ip_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | { |
| 436 | struct iphdr *iph; |
| 437 | int raw = 0; |
| 438 | int ptr; |
| 439 | struct net_device *dev; |
| 440 | struct sk_buff *skb2; |
Stephen Hemminger | 9bcfcaf | 2006-08-29 17:48:57 -0700 | [diff] [blame] | 441 | unsigned int mtu, hlen, left, len, ll_rs, pad; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | int offset; |
Alexey Dobriyan | 76ab608 | 2006-01-06 13:24:29 -0800 | [diff] [blame] | 443 | __be16 not_last_frag; |
Eric Dumazet | 511c3f9 | 2009-06-02 05:14:27 +0000 | [diff] [blame] | 444 | struct rtable *rt = skb_rtable(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | int err = 0; |
| 446 | |
| 447 | dev = rt->u.dst.dev; |
| 448 | |
| 449 | /* |
| 450 | * Point into the IP datagram header. |
| 451 | */ |
| 452 | |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 453 | iph = ip_hdr(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 454 | |
| 455 | if (unlikely((iph->frag_off & htons(IP_DF)) && !skb->local_df)) { |
Pavel Emelyanov | 5e38e27 | 2008-07-16 20:19:49 -0700 | [diff] [blame] | 456 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 457 | icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, |
John Heffner | 628a5c5 | 2007-04-20 15:53:27 -0700 | [diff] [blame] | 458 | htonl(ip_skb_dst_mtu(skb))); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | kfree_skb(skb); |
| 460 | return -EMSGSIZE; |
| 461 | } |
| 462 | |
| 463 | /* |
| 464 | * Setup starting values. |
| 465 | */ |
| 466 | |
| 467 | hlen = iph->ihl * 4; |
| 468 | mtu = dst_mtu(&rt->u.dst) - hlen; /* Size of data space */ |
Herbert Xu | 89cee8b | 2005-12-13 23:14:27 -0800 | [diff] [blame] | 469 | IPCB(skb)->flags |= IPSKB_FRAG_COMPLETE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | |
| 471 | /* When frag_list is given, use it. First, check its validity: |
| 472 | * some transformers could create wrong frag_list or break existing |
| 473 | * one, it is not prohibited. In this case fall back to copying. |
| 474 | * |
| 475 | * LATER: this step can be merged to real generation of fragments, |
| 476 | * we can switch to copy when see the first bad fragment. |
| 477 | */ |
David S. Miller | d7fcf1a | 2009-06-09 00:19:37 -0700 | [diff] [blame] | 478 | if (skb_has_frags(skb)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | struct sk_buff *frag; |
| 480 | int first_len = skb_pagelen(skb); |
Herbert Xu | 29ffe1a | 2008-01-28 20:45:20 -0800 | [diff] [blame] | 481 | int truesizes = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | |
| 483 | if (first_len - hlen > mtu || |
| 484 | ((first_len - hlen) & 7) || |
| 485 | (iph->frag_off & htons(IP_MF|IP_OFFSET)) || |
| 486 | skb_cloned(skb)) |
| 487 | goto slow_path; |
| 488 | |
David S. Miller | d7fcf1a | 2009-06-09 00:19:37 -0700 | [diff] [blame] | 489 | skb_walk_frags(skb, frag) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 490 | /* Correct geometry. */ |
| 491 | if (frag->len > mtu || |
| 492 | ((frag->len & 7) && frag->next) || |
| 493 | skb_headroom(frag) < hlen) |
| 494 | goto slow_path; |
| 495 | |
| 496 | /* Partially cloned skb? */ |
| 497 | if (skb_shared(frag)) |
| 498 | goto slow_path; |
Herbert Xu | 2fdba6b | 2005-05-18 22:52:33 -0700 | [diff] [blame] | 499 | |
| 500 | BUG_ON(frag->sk); |
| 501 | if (skb->sk) { |
Herbert Xu | 2fdba6b | 2005-05-18 22:52:33 -0700 | [diff] [blame] | 502 | frag->sk = skb->sk; |
| 503 | frag->destructor = sock_wfree; |
Herbert Xu | 29ffe1a | 2008-01-28 20:45:20 -0800 | [diff] [blame] | 504 | truesizes += frag->truesize; |
Herbert Xu | 2fdba6b | 2005-05-18 22:52:33 -0700 | [diff] [blame] | 505 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | } |
| 507 | |
| 508 | /* Everything is OK. Generate! */ |
| 509 | |
| 510 | err = 0; |
| 511 | offset = 0; |
| 512 | frag = skb_shinfo(skb)->frag_list; |
David S. Miller | d7fcf1a | 2009-06-09 00:19:37 -0700 | [diff] [blame] | 513 | skb_frag_list_init(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | skb->data_len = first_len - skb_headlen(skb); |
Herbert Xu | 29ffe1a | 2008-01-28 20:45:20 -0800 | [diff] [blame] | 515 | skb->truesize -= truesizes; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | skb->len = first_len; |
| 517 | iph->tot_len = htons(first_len); |
| 518 | iph->frag_off = htons(IP_MF); |
| 519 | ip_send_check(iph); |
| 520 | |
| 521 | for (;;) { |
| 522 | /* Prepare header of the next frame, |
| 523 | * before previous one went down. */ |
| 524 | if (frag) { |
| 525 | frag->ip_summed = CHECKSUM_NONE; |
Arnaldo Carvalho de Melo | badff6d | 2007-03-13 13:06:52 -0300 | [diff] [blame] | 526 | skb_reset_transport_header(frag); |
Arnaldo Carvalho de Melo | e2d1bca | 2007-04-10 20:46:21 -0700 | [diff] [blame] | 527 | __skb_push(frag, hlen); |
| 528 | skb_reset_network_header(frag); |
Arnaldo Carvalho de Melo | d56f90a | 2007-04-10 20:50:43 -0700 | [diff] [blame] | 529 | memcpy(skb_network_header(frag), iph, hlen); |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 530 | iph = ip_hdr(frag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 531 | iph->tot_len = htons(frag->len); |
| 532 | ip_copy_metadata(frag, skb); |
| 533 | if (offset == 0) |
| 534 | ip_options_fragment(frag); |
| 535 | offset += skb->len - hlen; |
| 536 | iph->frag_off = htons(offset>>3); |
| 537 | if (frag->next != NULL) |
| 538 | iph->frag_off |= htons(IP_MF); |
| 539 | /* Ready, complete checksum */ |
| 540 | ip_send_check(iph); |
| 541 | } |
| 542 | |
| 543 | err = output(skb); |
| 544 | |
Wei Dong | dafee49 | 2006-08-02 13:41:21 -0700 | [diff] [blame] | 545 | if (!err) |
Pavel Emelyanov | 5e38e27 | 2008-07-16 20:19:49 -0700 | [diff] [blame] | 546 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 547 | if (err || !frag) |
| 548 | break; |
| 549 | |
| 550 | skb = frag; |
| 551 | frag = skb->next; |
| 552 | skb->next = NULL; |
| 553 | } |
| 554 | |
| 555 | if (err == 0) { |
Pavel Emelyanov | 5e38e27 | 2008-07-16 20:19:49 -0700 | [diff] [blame] | 556 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | return 0; |
| 558 | } |
| 559 | |
| 560 | while (frag) { |
| 561 | skb = frag->next; |
| 562 | kfree_skb(frag); |
| 563 | frag = skb; |
| 564 | } |
Pavel Emelyanov | 5e38e27 | 2008-07-16 20:19:49 -0700 | [diff] [blame] | 565 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 566 | return err; |
| 567 | } |
| 568 | |
| 569 | slow_path: |
| 570 | left = skb->len - hlen; /* Space per frame */ |
| 571 | ptr = raw + hlen; /* Where to start from */ |
| 572 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | /* for bridged IP traffic encapsulated inside f.e. a vlan header, |
Stephen Hemminger | 9bcfcaf | 2006-08-29 17:48:57 -0700 | [diff] [blame] | 574 | * we need to make room for the encapsulating header |
| 575 | */ |
| 576 | pad = nf_bridge_pad(skb); |
| 577 | ll_rs = LL_RESERVED_SPACE_EXTRA(rt->u.dst.dev, pad); |
| 578 | mtu -= pad; |
| 579 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 580 | /* |
| 581 | * Fragment the datagram. |
| 582 | */ |
| 583 | |
| 584 | offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; |
| 585 | not_last_frag = iph->frag_off & htons(IP_MF); |
| 586 | |
| 587 | /* |
| 588 | * Keep copying data until we run out. |
| 589 | */ |
| 590 | |
Stephen Hemminger | 132adf5 | 2007-03-08 20:44:43 -0800 | [diff] [blame] | 591 | while (left > 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 592 | len = left; |
| 593 | /* IF: it doesn't fit, use 'mtu' - the data space left */ |
| 594 | if (len > mtu) |
| 595 | len = mtu; |
| 596 | /* IF: we are not sending upto and including the packet end |
| 597 | then align the next start on an eight byte boundary */ |
| 598 | if (len < left) { |
| 599 | len &= ~7; |
| 600 | } |
| 601 | /* |
| 602 | * Allocate buffer. |
| 603 | */ |
| 604 | |
| 605 | if ((skb2 = alloc_skb(len+hlen+ll_rs, GFP_ATOMIC)) == NULL) { |
Patrick McHardy | 64ce207 | 2005-08-09 20:50:53 -0700 | [diff] [blame] | 606 | NETDEBUG(KERN_INFO "IP: frag: no memory for new fragment!\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | err = -ENOMEM; |
| 608 | goto fail; |
| 609 | } |
| 610 | |
| 611 | /* |
| 612 | * Set up data on packet |
| 613 | */ |
| 614 | |
| 615 | ip_copy_metadata(skb2, skb); |
| 616 | skb_reserve(skb2, ll_rs); |
| 617 | skb_put(skb2, len + hlen); |
Arnaldo Carvalho de Melo | c1d2bbe | 2007-04-10 20:45:18 -0700 | [diff] [blame] | 618 | skb_reset_network_header(skb2); |
Arnaldo Carvalho de Melo | b0e380b | 2007-04-10 21:21:55 -0700 | [diff] [blame] | 619 | skb2->transport_header = skb2->network_header + hlen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 620 | |
| 621 | /* |
| 622 | * Charge the memory for the fragment to any owner |
| 623 | * it might possess |
| 624 | */ |
| 625 | |
| 626 | if (skb->sk) |
| 627 | skb_set_owner_w(skb2, skb->sk); |
| 628 | |
| 629 | /* |
| 630 | * Copy the packet header into the new buffer. |
| 631 | */ |
| 632 | |
Arnaldo Carvalho de Melo | d626f62 | 2007-03-27 18:55:52 -0300 | [diff] [blame] | 633 | skb_copy_from_linear_data(skb, skb_network_header(skb2), hlen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 634 | |
| 635 | /* |
| 636 | * Copy a block of the IP datagram. |
| 637 | */ |
Arnaldo Carvalho de Melo | bff9b61 | 2007-03-16 17:19:57 -0300 | [diff] [blame] | 638 | if (skb_copy_bits(skb, ptr, skb_transport_header(skb2), len)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 639 | BUG(); |
| 640 | left -= len; |
| 641 | |
| 642 | /* |
| 643 | * Fill in the new header fields. |
| 644 | */ |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 645 | iph = ip_hdr(skb2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 646 | iph->frag_off = htons((offset >> 3)); |
| 647 | |
| 648 | /* ANK: dirty, but effective trick. Upgrade options only if |
| 649 | * the segment to be fragmented was THE FIRST (otherwise, |
| 650 | * options are already fixed) and make it ONCE |
| 651 | * on the initial skb, so that all the following fragments |
| 652 | * will inherit fixed options. |
| 653 | */ |
| 654 | if (offset == 0) |
| 655 | ip_options_fragment(skb); |
| 656 | |
| 657 | /* |
| 658 | * Added AC : If we are fragmenting a fragment that's not the |
| 659 | * last fragment then keep MF on each bit |
| 660 | */ |
| 661 | if (left > 0 || not_last_frag) |
| 662 | iph->frag_off |= htons(IP_MF); |
| 663 | ptr += len; |
| 664 | offset += len; |
| 665 | |
| 666 | /* |
| 667 | * Put this fragment into the sending queue. |
| 668 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 669 | iph->tot_len = htons(len + hlen); |
| 670 | |
| 671 | ip_send_check(iph); |
| 672 | |
| 673 | err = output(skb2); |
| 674 | if (err) |
| 675 | goto fail; |
Wei Dong | dafee49 | 2006-08-02 13:41:21 -0700 | [diff] [blame] | 676 | |
Pavel Emelyanov | 5e38e27 | 2008-07-16 20:19:49 -0700 | [diff] [blame] | 677 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGCREATES); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 678 | } |
| 679 | kfree_skb(skb); |
Pavel Emelyanov | 5e38e27 | 2008-07-16 20:19:49 -0700 | [diff] [blame] | 680 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGOKS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 681 | return err; |
| 682 | |
| 683 | fail: |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 684 | kfree_skb(skb); |
Pavel Emelyanov | 5e38e27 | 2008-07-16 20:19:49 -0700 | [diff] [blame] | 685 | IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 686 | return err; |
| 687 | } |
| 688 | |
Patrick McHardy | 2e2f7ae | 2006-04-04 13:42:35 -0700 | [diff] [blame] | 689 | EXPORT_SYMBOL(ip_fragment); |
| 690 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | int |
| 692 | ip_generic_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) |
| 693 | { |
| 694 | struct iovec *iov = from; |
| 695 | |
Patrick McHardy | 84fa793 | 2006-08-29 16:44:56 -0700 | [diff] [blame] | 696 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 697 | if (memcpy_fromiovecend(to, iov, offset, len) < 0) |
| 698 | return -EFAULT; |
| 699 | } else { |
Al Viro | 44bb936 | 2006-11-14 21:36:14 -0800 | [diff] [blame] | 700 | __wsum csum = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 701 | if (csum_partial_copy_fromiovecend(to, iov, offset, len, &csum) < 0) |
| 702 | return -EFAULT; |
| 703 | skb->csum = csum_block_add(skb->csum, csum, odd); |
| 704 | } |
| 705 | return 0; |
| 706 | } |
| 707 | |
Al Viro | 44bb936 | 2006-11-14 21:36:14 -0800 | [diff] [blame] | 708 | static inline __wsum |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 709 | csum_page(struct page *page, int offset, int copy) |
| 710 | { |
| 711 | char *kaddr; |
Al Viro | 44bb936 | 2006-11-14 21:36:14 -0800 | [diff] [blame] | 712 | __wsum csum; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 713 | kaddr = kmap(page); |
| 714 | csum = csum_partial(kaddr + offset, copy, 0); |
| 715 | kunmap(page); |
| 716 | return csum; |
| 717 | } |
| 718 | |
Adrian Bunk | 4b30b1c | 2005-11-29 16:27:20 -0800 | [diff] [blame] | 719 | static inline int ip_ufo_append_data(struct sock *sk, |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 720 | int getfrag(void *from, char *to, int offset, int len, |
| 721 | int odd, struct sk_buff *skb), |
| 722 | void *from, int length, int hh_len, int fragheaderlen, |
Jianjun Kong | d9319100 | 2008-11-03 00:23:42 -0800 | [diff] [blame] | 723 | int transhdrlen, int mtu, unsigned int flags) |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 724 | { |
| 725 | struct sk_buff *skb; |
| 726 | int err; |
| 727 | |
| 728 | /* There is support for UDP fragmentation offload by network |
| 729 | * device, so create one single skb packet containing complete |
| 730 | * udp datagram |
| 731 | */ |
| 732 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) { |
| 733 | skb = sock_alloc_send_skb(sk, |
| 734 | hh_len + fragheaderlen + transhdrlen + 20, |
| 735 | (flags & MSG_DONTWAIT), &err); |
| 736 | |
| 737 | if (skb == NULL) |
| 738 | return err; |
| 739 | |
| 740 | /* reserve space for Hardware header */ |
| 741 | skb_reserve(skb, hh_len); |
| 742 | |
| 743 | /* create space for UDP/IP header */ |
Jianjun Kong | d9319100 | 2008-11-03 00:23:42 -0800 | [diff] [blame] | 744 | skb_put(skb, fragheaderlen + transhdrlen); |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 745 | |
| 746 | /* initialize network header pointer */ |
Arnaldo Carvalho de Melo | c1d2bbe | 2007-04-10 20:45:18 -0700 | [diff] [blame] | 747 | skb_reset_network_header(skb); |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 748 | |
| 749 | /* initialize protocol header pointer */ |
Arnaldo Carvalho de Melo | b0e380b | 2007-04-10 21:21:55 -0700 | [diff] [blame] | 750 | skb->transport_header = skb->network_header + fragheaderlen; |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 751 | |
Patrick McHardy | 84fa793 | 2006-08-29 16:44:56 -0700 | [diff] [blame] | 752 | skb->ip_summed = CHECKSUM_PARTIAL; |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 753 | skb->csum = 0; |
| 754 | sk->sk_sndmsg_off = 0; |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 755 | |
Kostya B | be9164e | 2008-04-29 22:36:30 -0700 | [diff] [blame] | 756 | /* specify the length of each IP datagram fragment */ |
Herbert Xu | 7967168 | 2006-06-22 02:40:14 -0700 | [diff] [blame] | 757 | skb_shinfo(skb)->gso_size = mtu - fragheaderlen; |
Herbert Xu | f83ef8c | 2006-06-30 13:37:03 -0700 | [diff] [blame] | 758 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 759 | __skb_queue_tail(&sk->sk_write_queue, skb); |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 760 | } |
Kostya B | be9164e | 2008-04-29 22:36:30 -0700 | [diff] [blame] | 761 | |
| 762 | return skb_append_datato_frags(sk, skb, getfrag, from, |
| 763 | (length - transhdrlen)); |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 764 | } |
| 765 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 766 | /* |
| 767 | * ip_append_data() and ip_append_page() can make one large IP datagram |
| 768 | * from many pieces of data. Each pieces will be holded on the socket |
| 769 | * until ip_push_pending_frames() is called. Each piece can be a page |
| 770 | * or non-page data. |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 771 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 772 | * Not only UDP, other transport protocols - e.g. raw sockets - can use |
| 773 | * this interface potentially. |
| 774 | * |
| 775 | * LATER: length must be adjusted by pad at tail, when it is required. |
| 776 | */ |
| 777 | int ip_append_data(struct sock *sk, |
| 778 | int getfrag(void *from, char *to, int offset, int len, |
| 779 | int odd, struct sk_buff *skb), |
| 780 | void *from, int length, int transhdrlen, |
Eric Dumazet | 2e77d89 | 2008-11-24 15:52:46 -0800 | [diff] [blame] | 781 | struct ipcm_cookie *ipc, struct rtable **rtp, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 782 | unsigned int flags) |
| 783 | { |
| 784 | struct inet_sock *inet = inet_sk(sk); |
| 785 | struct sk_buff *skb; |
| 786 | |
| 787 | struct ip_options *opt = NULL; |
| 788 | int hh_len; |
| 789 | int exthdrlen; |
| 790 | int mtu; |
| 791 | int copy; |
| 792 | int err; |
| 793 | int offset = 0; |
| 794 | unsigned int maxfraglen, fragheaderlen; |
| 795 | int csummode = CHECKSUM_NONE; |
Eric Dumazet | 2e77d89 | 2008-11-24 15:52:46 -0800 | [diff] [blame] | 796 | struct rtable *rt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 797 | |
| 798 | if (flags&MSG_PROBE) |
| 799 | return 0; |
| 800 | |
| 801 | if (skb_queue_empty(&sk->sk_write_queue)) { |
| 802 | /* |
| 803 | * setup for corking. |
| 804 | */ |
| 805 | opt = ipc->opt; |
| 806 | if (opt) { |
| 807 | if (inet->cork.opt == NULL) { |
| 808 | inet->cork.opt = kmalloc(sizeof(struct ip_options) + 40, sk->sk_allocation); |
| 809 | if (unlikely(inet->cork.opt == NULL)) |
| 810 | return -ENOBUFS; |
| 811 | } |
| 812 | memcpy(inet->cork.opt, opt, sizeof(struct ip_options)+opt->optlen); |
| 813 | inet->cork.flags |= IPCORK_OPT; |
| 814 | inet->cork.addr = ipc->addr; |
| 815 | } |
Eric Dumazet | 2e77d89 | 2008-11-24 15:52:46 -0800 | [diff] [blame] | 816 | rt = *rtp; |
Julien TINNES | 788d908 | 2009-08-27 15:26:58 +0200 | [diff] [blame] | 817 | if (unlikely(!rt)) |
| 818 | return -EFAULT; |
Eric Dumazet | 2e77d89 | 2008-11-24 15:52:46 -0800 | [diff] [blame] | 819 | /* |
| 820 | * We steal reference to this route, caller should not release it |
| 821 | */ |
| 822 | *rtp = NULL; |
John Heffner | 628a5c5 | 2007-04-20 15:53:27 -0700 | [diff] [blame] | 823 | inet->cork.fragsize = mtu = inet->pmtudisc == IP_PMTUDISC_PROBE ? |
| 824 | rt->u.dst.dev->mtu : |
| 825 | dst_mtu(rt->u.dst.path); |
YOSHIFUJI Hideaki | c8cdaf9 | 2008-03-10 04:30:37 -0400 | [diff] [blame] | 826 | inet->cork.dst = &rt->u.dst; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | inet->cork.length = 0; |
| 828 | sk->sk_sndmsg_page = NULL; |
| 829 | sk->sk_sndmsg_off = 0; |
| 830 | if ((exthdrlen = rt->u.dst.header_len) != 0) { |
| 831 | length += exthdrlen; |
| 832 | transhdrlen += exthdrlen; |
| 833 | } |
| 834 | } else { |
YOSHIFUJI Hideaki | c8cdaf9 | 2008-03-10 04:30:37 -0400 | [diff] [blame] | 835 | rt = (struct rtable *)inet->cork.dst; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 836 | if (inet->cork.flags & IPCORK_OPT) |
| 837 | opt = inet->cork.opt; |
| 838 | |
| 839 | transhdrlen = 0; |
| 840 | exthdrlen = 0; |
| 841 | mtu = inet->cork.fragsize; |
| 842 | } |
| 843 | hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); |
| 844 | |
| 845 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); |
| 846 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; |
| 847 | |
| 848 | if (inet->cork.length + length > 0xFFFF - fragheaderlen) { |
| 849 | ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu-exthdrlen); |
| 850 | return -EMSGSIZE; |
| 851 | } |
| 852 | |
| 853 | /* |
| 854 | * transhdrlen > 0 means that this is the first fragment and we wish |
| 855 | * it won't be fragmented in the future. |
| 856 | */ |
| 857 | if (transhdrlen && |
| 858 | length + fragheaderlen <= mtu && |
Stephen Hemminger | d212f87 | 2007-06-27 00:47:37 -0700 | [diff] [blame] | 859 | rt->u.dst.dev->features & NETIF_F_V4_CSUM && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 860 | !exthdrlen) |
Patrick McHardy | 84fa793 | 2006-08-29 16:44:56 -0700 | [diff] [blame] | 861 | csummode = CHECKSUM_PARTIAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 862 | |
| 863 | inet->cork.length += length; |
Kostya B | be9164e | 2008-04-29 22:36:30 -0700 | [diff] [blame] | 864 | if (((length> mtu) || !skb_queue_empty(&sk->sk_write_queue)) && |
| 865 | (sk->sk_protocol == IPPROTO_UDP) && |
| 866 | (rt->u.dst.dev->features & NETIF_F_UFO)) { |
Patrick McHardy | baa829d | 2006-03-12 20:35:12 -0800 | [diff] [blame] | 867 | err = ip_ufo_append_data(sk, getfrag, from, length, hh_len, |
| 868 | fragheaderlen, transhdrlen, mtu, |
| 869 | flags); |
| 870 | if (err) |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 871 | goto error; |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 872 | return 0; |
| 873 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 874 | |
| 875 | /* So, what's going on in the loop below? |
| 876 | * |
| 877 | * We use calculated fragment length to generate chained skb, |
| 878 | * each of segments is IP fragment ready for sending to network after |
| 879 | * adding appropriate IP header. |
| 880 | */ |
| 881 | |
| 882 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) |
| 883 | goto alloc_new_skb; |
| 884 | |
| 885 | while (length > 0) { |
| 886 | /* Check if the remaining data fits into current packet. */ |
| 887 | copy = mtu - skb->len; |
| 888 | if (copy < length) |
| 889 | copy = maxfraglen - skb->len; |
| 890 | if (copy <= 0) { |
| 891 | char *data; |
| 892 | unsigned int datalen; |
| 893 | unsigned int fraglen; |
| 894 | unsigned int fraggap; |
| 895 | unsigned int alloclen; |
| 896 | struct sk_buff *skb_prev; |
| 897 | alloc_new_skb: |
| 898 | skb_prev = skb; |
| 899 | if (skb_prev) |
| 900 | fraggap = skb_prev->len - maxfraglen; |
| 901 | else |
| 902 | fraggap = 0; |
| 903 | |
| 904 | /* |
| 905 | * If remaining data exceeds the mtu, |
| 906 | * we know we need more fragment(s). |
| 907 | */ |
| 908 | datalen = length + fraggap; |
| 909 | if (datalen > mtu - fragheaderlen) |
| 910 | datalen = maxfraglen - fragheaderlen; |
| 911 | fraglen = datalen + fragheaderlen; |
| 912 | |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 913 | if ((flags & MSG_MORE) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 914 | !(rt->u.dst.dev->features&NETIF_F_SG)) |
| 915 | alloclen = mtu; |
| 916 | else |
| 917 | alloclen = datalen + fragheaderlen; |
| 918 | |
| 919 | /* The last fragment gets additional space at tail. |
| 920 | * Note, with MSG_MORE we overallocate on fragments, |
| 921 | * because we have no idea what fragment will be |
| 922 | * the last. |
| 923 | */ |
Zach Brown | 3d9dd75 | 2006-04-14 16:04:18 -0700 | [diff] [blame] | 924 | if (datalen == length + fraggap) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 925 | alloclen += rt->u.dst.trailer_len; |
| 926 | |
| 927 | if (transhdrlen) { |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 928 | skb = sock_alloc_send_skb(sk, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 929 | alloclen + hh_len + 15, |
| 930 | (flags & MSG_DONTWAIT), &err); |
| 931 | } else { |
| 932 | skb = NULL; |
| 933 | if (atomic_read(&sk->sk_wmem_alloc) <= |
| 934 | 2 * sk->sk_sndbuf) |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 935 | skb = sock_wmalloc(sk, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 936 | alloclen + hh_len + 15, 1, |
| 937 | sk->sk_allocation); |
| 938 | if (unlikely(skb == NULL)) |
| 939 | err = -ENOBUFS; |
Patrick Ohly | 51f31ca | 2009-02-12 05:03:39 +0000 | [diff] [blame] | 940 | else |
| 941 | /* only the initial fragment is |
| 942 | time stamped */ |
| 943 | ipc->shtx.flags = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 944 | } |
| 945 | if (skb == NULL) |
| 946 | goto error; |
| 947 | |
| 948 | /* |
| 949 | * Fill in the control structures |
| 950 | */ |
| 951 | skb->ip_summed = csummode; |
| 952 | skb->csum = 0; |
| 953 | skb_reserve(skb, hh_len); |
Patrick Ohly | 51f31ca | 2009-02-12 05:03:39 +0000 | [diff] [blame] | 954 | *skb_tx(skb) = ipc->shtx; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 955 | |
| 956 | /* |
| 957 | * Find where to start putting bytes. |
| 958 | */ |
| 959 | data = skb_put(skb, fraglen); |
Arnaldo Carvalho de Melo | c14d245 | 2007-03-11 22:39:41 -0300 | [diff] [blame] | 960 | skb_set_network_header(skb, exthdrlen); |
Arnaldo Carvalho de Melo | b0e380b | 2007-04-10 21:21:55 -0700 | [diff] [blame] | 961 | skb->transport_header = (skb->network_header + |
| 962 | fragheaderlen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 963 | data += fragheaderlen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 964 | |
| 965 | if (fraggap) { |
| 966 | skb->csum = skb_copy_and_csum_bits( |
| 967 | skb_prev, maxfraglen, |
| 968 | data + transhdrlen, fraggap, 0); |
| 969 | skb_prev->csum = csum_sub(skb_prev->csum, |
| 970 | skb->csum); |
| 971 | data += fraggap; |
Herbert Xu | e9fa4f7 | 2006-08-13 20:12:58 -0700 | [diff] [blame] | 972 | pskb_trim_unique(skb_prev, maxfraglen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 973 | } |
| 974 | |
| 975 | copy = datalen - transhdrlen - fraggap; |
| 976 | if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) { |
| 977 | err = -EFAULT; |
| 978 | kfree_skb(skb); |
| 979 | goto error; |
| 980 | } |
| 981 | |
| 982 | offset += copy; |
| 983 | length -= datalen - fraggap; |
| 984 | transhdrlen = 0; |
| 985 | exthdrlen = 0; |
| 986 | csummode = CHECKSUM_NONE; |
| 987 | |
| 988 | /* |
| 989 | * Put the packet on the pending queue. |
| 990 | */ |
| 991 | __skb_queue_tail(&sk->sk_write_queue, skb); |
| 992 | continue; |
| 993 | } |
| 994 | |
| 995 | if (copy > length) |
| 996 | copy = length; |
| 997 | |
| 998 | if (!(rt->u.dst.dev->features&NETIF_F_SG)) { |
| 999 | unsigned int off; |
| 1000 | |
| 1001 | off = skb->len; |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 1002 | if (getfrag(from, skb_put(skb, copy), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1003 | offset, copy, off, skb) < 0) { |
| 1004 | __skb_trim(skb, off); |
| 1005 | err = -EFAULT; |
| 1006 | goto error; |
| 1007 | } |
| 1008 | } else { |
| 1009 | int i = skb_shinfo(skb)->nr_frags; |
| 1010 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i-1]; |
| 1011 | struct page *page = sk->sk_sndmsg_page; |
| 1012 | int off = sk->sk_sndmsg_off; |
| 1013 | unsigned int left; |
| 1014 | |
| 1015 | if (page && (left = PAGE_SIZE - off) > 0) { |
| 1016 | if (copy >= left) |
| 1017 | copy = left; |
| 1018 | if (page != frag->page) { |
| 1019 | if (i == MAX_SKB_FRAGS) { |
| 1020 | err = -EMSGSIZE; |
| 1021 | goto error; |
| 1022 | } |
| 1023 | get_page(page); |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 1024 | skb_fill_page_desc(skb, i, page, sk->sk_sndmsg_off, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1025 | frag = &skb_shinfo(skb)->frags[i]; |
| 1026 | } |
| 1027 | } else if (i < MAX_SKB_FRAGS) { |
| 1028 | if (copy > PAGE_SIZE) |
| 1029 | copy = PAGE_SIZE; |
| 1030 | page = alloc_pages(sk->sk_allocation, 0); |
| 1031 | if (page == NULL) { |
| 1032 | err = -ENOMEM; |
| 1033 | goto error; |
| 1034 | } |
| 1035 | sk->sk_sndmsg_page = page; |
| 1036 | sk->sk_sndmsg_off = 0; |
| 1037 | |
| 1038 | skb_fill_page_desc(skb, i, page, 0, 0); |
| 1039 | frag = &skb_shinfo(skb)->frags[i]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1040 | } else { |
| 1041 | err = -EMSGSIZE; |
| 1042 | goto error; |
| 1043 | } |
| 1044 | if (getfrag(from, page_address(frag->page)+frag->page_offset+frag->size, offset, copy, skb->len, skb) < 0) { |
| 1045 | err = -EFAULT; |
| 1046 | goto error; |
| 1047 | } |
| 1048 | sk->sk_sndmsg_off += copy; |
| 1049 | frag->size += copy; |
| 1050 | skb->len += copy; |
| 1051 | skb->data_len += copy; |
Herbert Xu | f945fa7 | 2008-01-22 22:39:26 -0800 | [diff] [blame] | 1052 | skb->truesize += copy; |
| 1053 | atomic_add(copy, &sk->sk_wmem_alloc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1054 | } |
| 1055 | offset += copy; |
| 1056 | length -= copy; |
| 1057 | } |
| 1058 | |
| 1059 | return 0; |
| 1060 | |
| 1061 | error: |
| 1062 | inet->cork.length -= length; |
Pavel Emelyanov | 5e38e27 | 2008-07-16 20:19:49 -0700 | [diff] [blame] | 1063 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 1064 | return err; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1065 | } |
| 1066 | |
| 1067 | ssize_t ip_append_page(struct sock *sk, struct page *page, |
| 1068 | int offset, size_t size, int flags) |
| 1069 | { |
| 1070 | struct inet_sock *inet = inet_sk(sk); |
| 1071 | struct sk_buff *skb; |
| 1072 | struct rtable *rt; |
| 1073 | struct ip_options *opt = NULL; |
| 1074 | int hh_len; |
| 1075 | int mtu; |
| 1076 | int len; |
| 1077 | int err; |
| 1078 | unsigned int maxfraglen, fragheaderlen, fraggap; |
| 1079 | |
| 1080 | if (inet->hdrincl) |
| 1081 | return -EPERM; |
| 1082 | |
| 1083 | if (flags&MSG_PROBE) |
| 1084 | return 0; |
| 1085 | |
| 1086 | if (skb_queue_empty(&sk->sk_write_queue)) |
| 1087 | return -EINVAL; |
| 1088 | |
YOSHIFUJI Hideaki | c8cdaf9 | 2008-03-10 04:30:37 -0400 | [diff] [blame] | 1089 | rt = (struct rtable *)inet->cork.dst; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1090 | if (inet->cork.flags & IPCORK_OPT) |
| 1091 | opt = inet->cork.opt; |
| 1092 | |
| 1093 | if (!(rt->u.dst.dev->features&NETIF_F_SG)) |
| 1094 | return -EOPNOTSUPP; |
| 1095 | |
| 1096 | hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); |
| 1097 | mtu = inet->cork.fragsize; |
| 1098 | |
| 1099 | fragheaderlen = sizeof(struct iphdr) + (opt ? opt->optlen : 0); |
| 1100 | maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen; |
| 1101 | |
| 1102 | if (inet->cork.length + size > 0xFFFF - fragheaderlen) { |
| 1103 | ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport, mtu); |
| 1104 | return -EMSGSIZE; |
| 1105 | } |
| 1106 | |
| 1107 | if ((skb = skb_peek_tail(&sk->sk_write_queue)) == NULL) |
| 1108 | return -EINVAL; |
| 1109 | |
| 1110 | inet->cork.length += size; |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 1111 | if ((sk->sk_protocol == IPPROTO_UDP) && |
Herbert Xu | 7967168 | 2006-06-22 02:40:14 -0700 | [diff] [blame] | 1112 | (rt->u.dst.dev->features & NETIF_F_UFO)) { |
| 1113 | skb_shinfo(skb)->gso_size = mtu - fragheaderlen; |
Herbert Xu | f83ef8c | 2006-06-30 13:37:03 -0700 | [diff] [blame] | 1114 | skb_shinfo(skb)->gso_type = SKB_GSO_UDP; |
Herbert Xu | 7967168 | 2006-06-22 02:40:14 -0700 | [diff] [blame] | 1115 | } |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 1116 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1117 | |
| 1118 | while (size > 0) { |
| 1119 | int i; |
| 1120 | |
Herbert Xu | 89114af | 2006-07-08 13:34:32 -0700 | [diff] [blame] | 1121 | if (skb_is_gso(skb)) |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 1122 | len = size; |
| 1123 | else { |
| 1124 | |
| 1125 | /* Check if the remaining data fits into current packet. */ |
| 1126 | len = mtu - skb->len; |
| 1127 | if (len < size) |
| 1128 | len = maxfraglen - skb->len; |
| 1129 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1130 | if (len <= 0) { |
| 1131 | struct sk_buff *skb_prev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1132 | int alloclen; |
| 1133 | |
| 1134 | skb_prev = skb; |
Jayachandran C | 0d0d2bb | 2005-10-13 11:43:02 -0700 | [diff] [blame] | 1135 | fraggap = skb_prev->len - maxfraglen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1136 | |
| 1137 | alloclen = fragheaderlen + hh_len + fraggap + 15; |
| 1138 | skb = sock_wmalloc(sk, alloclen, 1, sk->sk_allocation); |
| 1139 | if (unlikely(!skb)) { |
| 1140 | err = -ENOBUFS; |
| 1141 | goto error; |
| 1142 | } |
| 1143 | |
| 1144 | /* |
| 1145 | * Fill in the control structures |
| 1146 | */ |
| 1147 | skb->ip_summed = CHECKSUM_NONE; |
| 1148 | skb->csum = 0; |
| 1149 | skb_reserve(skb, hh_len); |
| 1150 | |
| 1151 | /* |
| 1152 | * Find where to start putting bytes. |
| 1153 | */ |
Arnaldo Carvalho de Melo | 967b05f | 2007-03-13 13:51:52 -0300 | [diff] [blame] | 1154 | skb_put(skb, fragheaderlen + fraggap); |
Arnaldo Carvalho de Melo | 2ca9e6f | 2007-03-10 19:15:25 -0300 | [diff] [blame] | 1155 | skb_reset_network_header(skb); |
Arnaldo Carvalho de Melo | b0e380b | 2007-04-10 21:21:55 -0700 | [diff] [blame] | 1156 | skb->transport_header = (skb->network_header + |
| 1157 | fragheaderlen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1158 | if (fraggap) { |
Arnaldo Carvalho de Melo | 967b05f | 2007-03-13 13:51:52 -0300 | [diff] [blame] | 1159 | skb->csum = skb_copy_and_csum_bits(skb_prev, |
| 1160 | maxfraglen, |
Arnaldo Carvalho de Melo | 9c70220 | 2007-04-25 18:04:18 -0700 | [diff] [blame] | 1161 | skb_transport_header(skb), |
Arnaldo Carvalho de Melo | 967b05f | 2007-03-13 13:51:52 -0300 | [diff] [blame] | 1162 | fraggap, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1163 | skb_prev->csum = csum_sub(skb_prev->csum, |
| 1164 | skb->csum); |
Herbert Xu | e9fa4f7 | 2006-08-13 20:12:58 -0700 | [diff] [blame] | 1165 | pskb_trim_unique(skb_prev, maxfraglen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1166 | } |
| 1167 | |
| 1168 | /* |
| 1169 | * Put the packet on the pending queue. |
| 1170 | */ |
| 1171 | __skb_queue_tail(&sk->sk_write_queue, skb); |
| 1172 | continue; |
| 1173 | } |
| 1174 | |
| 1175 | i = skb_shinfo(skb)->nr_frags; |
| 1176 | if (len > size) |
| 1177 | len = size; |
| 1178 | if (skb_can_coalesce(skb, i, page, offset)) { |
| 1179 | skb_shinfo(skb)->frags[i-1].size += len; |
| 1180 | } else if (i < MAX_SKB_FRAGS) { |
| 1181 | get_page(page); |
| 1182 | skb_fill_page_desc(skb, i, page, offset, len); |
| 1183 | } else { |
| 1184 | err = -EMSGSIZE; |
| 1185 | goto error; |
| 1186 | } |
| 1187 | |
| 1188 | if (skb->ip_summed == CHECKSUM_NONE) { |
Al Viro | 44bb936 | 2006-11-14 21:36:14 -0800 | [diff] [blame] | 1189 | __wsum csum; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1190 | csum = csum_page(page, offset, len); |
| 1191 | skb->csum = csum_block_add(skb->csum, csum, skb->len); |
| 1192 | } |
| 1193 | |
| 1194 | skb->len += len; |
| 1195 | skb->data_len += len; |
David S. Miller | 1e34a11 | 2008-01-22 23:44:31 -0800 | [diff] [blame] | 1196 | skb->truesize += len; |
| 1197 | atomic_add(len, &sk->sk_wmem_alloc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1198 | offset += len; |
| 1199 | size -= len; |
| 1200 | } |
| 1201 | return 0; |
| 1202 | |
| 1203 | error: |
| 1204 | inet->cork.length -= size; |
Pavel Emelyanov | 5e38e27 | 2008-07-16 20:19:49 -0700 | [diff] [blame] | 1205 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTDISCARDS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1206 | return err; |
| 1207 | } |
| 1208 | |
Pavel Emelyanov | 429f08e | 2007-11-05 21:03:24 -0800 | [diff] [blame] | 1209 | static void ip_cork_release(struct inet_sock *inet) |
| 1210 | { |
| 1211 | inet->cork.flags &= ~IPCORK_OPT; |
| 1212 | kfree(inet->cork.opt); |
| 1213 | inet->cork.opt = NULL; |
YOSHIFUJI Hideaki | c8cdaf9 | 2008-03-10 04:30:37 -0400 | [diff] [blame] | 1214 | dst_release(inet->cork.dst); |
| 1215 | inet->cork.dst = NULL; |
Pavel Emelyanov | 429f08e | 2007-11-05 21:03:24 -0800 | [diff] [blame] | 1216 | } |
| 1217 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1218 | /* |
| 1219 | * Combined all pending IP fragments on the socket as one IP datagram |
| 1220 | * and push them out. |
| 1221 | */ |
| 1222 | int ip_push_pending_frames(struct sock *sk) |
| 1223 | { |
| 1224 | struct sk_buff *skb, *tmp_skb; |
| 1225 | struct sk_buff **tail_skb; |
| 1226 | struct inet_sock *inet = inet_sk(sk); |
Pavel Emelyanov | 0388b00 | 2008-07-14 23:00:43 -0700 | [diff] [blame] | 1227 | struct net *net = sock_net(sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1228 | struct ip_options *opt = NULL; |
YOSHIFUJI Hideaki | c8cdaf9 | 2008-03-10 04:30:37 -0400 | [diff] [blame] | 1229 | struct rtable *rt = (struct rtable *)inet->cork.dst; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1230 | struct iphdr *iph; |
Alexey Dobriyan | 76ab608 | 2006-01-06 13:24:29 -0800 | [diff] [blame] | 1231 | __be16 df = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1232 | __u8 ttl; |
| 1233 | int err = 0; |
| 1234 | |
| 1235 | if ((skb = __skb_dequeue(&sk->sk_write_queue)) == NULL) |
| 1236 | goto out; |
| 1237 | tail_skb = &(skb_shinfo(skb)->frag_list); |
| 1238 | |
| 1239 | /* move skb->data to ip header from ext header */ |
Arnaldo Carvalho de Melo | d56f90a | 2007-04-10 20:50:43 -0700 | [diff] [blame] | 1240 | if (skb->data < skb_network_header(skb)) |
Arnaldo Carvalho de Melo | bbe735e | 2007-03-10 22:16:10 -0300 | [diff] [blame] | 1241 | __skb_pull(skb, skb_network_offset(skb)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1242 | while ((tmp_skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) { |
Arnaldo Carvalho de Melo | cfe1fc7 | 2007-03-16 17:26:39 -0300 | [diff] [blame] | 1243 | __skb_pull(tmp_skb, skb_network_header_len(skb)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1244 | *tail_skb = tmp_skb; |
| 1245 | tail_skb = &(tmp_skb->next); |
| 1246 | skb->len += tmp_skb->len; |
| 1247 | skb->data_len += tmp_skb->len; |
| 1248 | skb->truesize += tmp_skb->truesize; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1249 | tmp_skb->destructor = NULL; |
| 1250 | tmp_skb->sk = NULL; |
| 1251 | } |
| 1252 | |
| 1253 | /* Unless user demanded real pmtu discovery (IP_PMTUDISC_DO), we allow |
| 1254 | * to fragment the frame generated here. No matter, what transforms |
| 1255 | * how transforms change size of the packet, it will come out. |
| 1256 | */ |
John Heffner | 628a5c5 | 2007-04-20 15:53:27 -0700 | [diff] [blame] | 1257 | if (inet->pmtudisc < IP_PMTUDISC_DO) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1258 | skb->local_df = 1; |
| 1259 | |
| 1260 | /* DF bit is set when we want to see DF on outgoing frames. |
| 1261 | * If local_df is set too, we still allow to fragment this frame |
| 1262 | * locally. */ |
John Heffner | 628a5c5 | 2007-04-20 15:53:27 -0700 | [diff] [blame] | 1263 | if (inet->pmtudisc >= IP_PMTUDISC_DO || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1264 | (skb->len <= dst_mtu(&rt->u.dst) && |
| 1265 | ip_dont_fragment(sk, &rt->u.dst))) |
| 1266 | df = htons(IP_DF); |
| 1267 | |
| 1268 | if (inet->cork.flags & IPCORK_OPT) |
| 1269 | opt = inet->cork.opt; |
| 1270 | |
| 1271 | if (rt->rt_type == RTN_MULTICAST) |
| 1272 | ttl = inet->mc_ttl; |
| 1273 | else |
| 1274 | ttl = ip_select_ttl(inet, &rt->u.dst); |
| 1275 | |
| 1276 | iph = (struct iphdr *)skb->data; |
| 1277 | iph->version = 4; |
| 1278 | iph->ihl = 5; |
| 1279 | if (opt) { |
| 1280 | iph->ihl += opt->optlen>>2; |
| 1281 | ip_options_build(skb, opt, inet->cork.addr, rt, 0); |
| 1282 | } |
| 1283 | iph->tos = inet->tos; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1284 | iph->frag_off = df; |
Alexey Kuznetsov | 1a55d57 | 2006-03-22 14:27:59 -0800 | [diff] [blame] | 1285 | ip_select_ident(iph, &rt->u.dst, sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1286 | iph->ttl = ttl; |
| 1287 | iph->protocol = sk->sk_protocol; |
| 1288 | iph->saddr = rt->rt_src; |
| 1289 | iph->daddr = rt->rt_dst; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1290 | |
| 1291 | skb->priority = sk->sk_priority; |
Laszlo Attila Toth | 4a19ec5 | 2008-01-30 19:08:16 -0800 | [diff] [blame] | 1292 | skb->mark = sk->sk_mark; |
Eric Dumazet | a21bba9 | 2008-11-24 16:07:50 -0800 | [diff] [blame] | 1293 | /* |
| 1294 | * Steal rt from cork.dst to avoid a pair of atomic_inc/atomic_dec |
| 1295 | * on dst refcount |
| 1296 | */ |
| 1297 | inet->cork.dst = NULL; |
Eric Dumazet | adf3090 | 2009-06-02 05:19:30 +0000 | [diff] [blame] | 1298 | skb_dst_set(skb, &rt->u.dst); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1299 | |
David L Stevens | 96793b4 | 2007-09-17 09:57:33 -0700 | [diff] [blame] | 1300 | if (iph->protocol == IPPROTO_ICMP) |
Pavel Emelyanov | 0388b00 | 2008-07-14 23:00:43 -0700 | [diff] [blame] | 1301 | icmp_out_count(net, ((struct icmphdr *) |
David L Stevens | 96793b4 | 2007-09-17 09:57:33 -0700 | [diff] [blame] | 1302 | skb_transport_header(skb))->type); |
| 1303 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1304 | /* Netfilter gets whole the not fragmented skb. */ |
Herbert Xu | c439cb2 | 2008-01-11 19:14:00 -0800 | [diff] [blame] | 1305 | err = ip_local_out(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1306 | if (err) { |
| 1307 | if (err > 0) |
Eric Dumazet | 6ce9e7b | 2009-09-02 18:05:33 -0700 | [diff] [blame] | 1308 | err = net_xmit_errno(err); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1309 | if (err) |
| 1310 | goto error; |
| 1311 | } |
| 1312 | |
| 1313 | out: |
Pavel Emelyanov | 429f08e | 2007-11-05 21:03:24 -0800 | [diff] [blame] | 1314 | ip_cork_release(inet); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1315 | return err; |
| 1316 | |
| 1317 | error: |
Pavel Emelyanov | 5e38e27 | 2008-07-16 20:19:49 -0700 | [diff] [blame] | 1318 | IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1319 | goto out; |
| 1320 | } |
| 1321 | |
| 1322 | /* |
| 1323 | * Throw away all pending data on the socket. |
| 1324 | */ |
| 1325 | void ip_flush_pending_frames(struct sock *sk) |
| 1326 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1327 | struct sk_buff *skb; |
| 1328 | |
| 1329 | while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) |
| 1330 | kfree_skb(skb); |
| 1331 | |
Pavel Emelyanov | 429f08e | 2007-11-05 21:03:24 -0800 | [diff] [blame] | 1332 | ip_cork_release(inet_sk(sk)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1333 | } |
| 1334 | |
| 1335 | |
| 1336 | /* |
| 1337 | * Fetch data from kernel space and fill in checksum if needed. |
| 1338 | */ |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 1339 | static int ip_reply_glue_bits(void *dptr, char *to, int offset, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1340 | int len, int odd, struct sk_buff *skb) |
| 1341 | { |
Al Viro | 5084205 | 2006-11-14 21:36:34 -0800 | [diff] [blame] | 1342 | __wsum csum; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1343 | |
| 1344 | csum = csum_partial_copy_nocheck(dptr+offset, to, len, 0); |
| 1345 | skb->csum = csum_block_add(skb->csum, csum, odd); |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 1346 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1347 | } |
| 1348 | |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 1349 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1350 | * Generic function to send a packet as reply to another packet. |
| 1351 | * Used to send TCP resets so far. ICMP should use this function too. |
| 1352 | * |
YOSHIFUJI Hideaki | e905a9e | 2007-02-09 23:24:47 +0900 | [diff] [blame] | 1353 | * Should run single threaded per socket because it uses the sock |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1354 | * structure to pass arguments. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1355 | */ |
| 1356 | void ip_send_reply(struct sock *sk, struct sk_buff *skb, struct ip_reply_arg *arg, |
| 1357 | unsigned int len) |
| 1358 | { |
| 1359 | struct inet_sock *inet = inet_sk(sk); |
| 1360 | struct { |
| 1361 | struct ip_options opt; |
| 1362 | char data[40]; |
| 1363 | } replyopts; |
| 1364 | struct ipcm_cookie ipc; |
Al Viro | 3ca3c68 | 2006-09-27 18:28:07 -0700 | [diff] [blame] | 1365 | __be32 daddr; |
Eric Dumazet | 511c3f9 | 2009-06-02 05:14:27 +0000 | [diff] [blame] | 1366 | struct rtable *rt = skb_rtable(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1367 | |
| 1368 | if (ip_options_echo(&replyopts.opt, skb)) |
| 1369 | return; |
| 1370 | |
| 1371 | daddr = ipc.addr = rt->rt_src; |
| 1372 | ipc.opt = NULL; |
Patrick Ohly | 51f31ca | 2009-02-12 05:03:39 +0000 | [diff] [blame] | 1373 | ipc.shtx.flags = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1374 | |
| 1375 | if (replyopts.opt.optlen) { |
| 1376 | ipc.opt = &replyopts.opt; |
| 1377 | |
| 1378 | if (ipc.opt->srr) |
| 1379 | daddr = replyopts.opt.faddr; |
| 1380 | } |
| 1381 | |
| 1382 | { |
Patrick McHardy | f0e48db | 2007-06-04 21:32:46 -0700 | [diff] [blame] | 1383 | struct flowi fl = { .oif = arg->bound_dev_if, |
| 1384 | .nl_u = { .ip4_u = |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1385 | { .daddr = daddr, |
| 1386 | .saddr = rt->rt_spec_dst, |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 1387 | .tos = RT_TOS(ip_hdr(skb)->tos) } }, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1388 | /* Not quite clean, but right. */ |
| 1389 | .uli_u = { .ports = |
Arnaldo Carvalho de Melo | aa8223c | 2007-04-10 21:04:22 -0700 | [diff] [blame] | 1390 | { .sport = tcp_hdr(skb)->dest, |
| 1391 | .dport = tcp_hdr(skb)->source } }, |
KOVACS Krisztian | 86b08d8 | 2008-10-01 07:44:42 -0700 | [diff] [blame] | 1392 | .proto = sk->sk_protocol, |
| 1393 | .flags = ip_reply_arg_flowi_flags(arg) }; |
Venkat Yekkirala | beb8d13 | 2006-08-04 23:12:42 -0700 | [diff] [blame] | 1394 | security_skb_classify_flow(skb, &fl); |
YOSHIFUJI Hideaki | 3b1e0a6 | 2008-03-26 02:26:21 +0900 | [diff] [blame] | 1395 | if (ip_route_output_key(sock_net(sk), &rt, &fl)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1396 | return; |
| 1397 | } |
| 1398 | |
| 1399 | /* And let IP do all the hard work. |
| 1400 | |
| 1401 | This chunk is not reenterable, hence spinlock. |
| 1402 | Note that it uses the fact, that this function is called |
| 1403 | with locally disabled BH and that sk cannot be already spinlocked. |
| 1404 | */ |
| 1405 | bh_lock_sock(sk); |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 1406 | inet->tos = ip_hdr(skb)->tos; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1407 | sk->sk_priority = skb->priority; |
Arnaldo Carvalho de Melo | eddc9ec | 2007-04-20 22:47:35 -0700 | [diff] [blame] | 1408 | sk->sk_protocol = ip_hdr(skb)->protocol; |
Patrick McHardy | f0e48db | 2007-06-04 21:32:46 -0700 | [diff] [blame] | 1409 | sk->sk_bound_dev_if = arg->bound_dev_if; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1410 | ip_append_data(sk, ip_reply_glue_bits, arg->iov->iov_base, len, 0, |
Eric Dumazet | 2e77d89 | 2008-11-24 15:52:46 -0800 | [diff] [blame] | 1411 | &ipc, &rt, MSG_DONTWAIT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1412 | if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) { |
| 1413 | if (arg->csumoffset >= 0) |
Arnaldo Carvalho de Melo | 9c70220 | 2007-04-25 18:04:18 -0700 | [diff] [blame] | 1414 | *((__sum16 *)skb_transport_header(skb) + |
| 1415 | arg->csumoffset) = csum_fold(csum_add(skb->csum, |
| 1416 | arg->csum)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1417 | skb->ip_summed = CHECKSUM_NONE; |
| 1418 | ip_push_pending_frames(sk); |
| 1419 | } |
| 1420 | |
| 1421 | bh_unlock_sock(sk); |
| 1422 | |
| 1423 | ip_rt_put(rt); |
| 1424 | } |
| 1425 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1426 | void __init ip_init(void) |
| 1427 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1428 | ip_rt_init(); |
| 1429 | inet_initpeers(); |
| 1430 | |
| 1431 | #if defined(CONFIG_IP_MULTICAST) && defined(CONFIG_PROC_FS) |
| 1432 | igmp_mc_proc_init(); |
| 1433 | #endif |
| 1434 | } |
| 1435 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1436 | EXPORT_SYMBOL(ip_generic_getfrag); |
| 1437 | EXPORT_SYMBOL(ip_queue_xmit); |
| 1438 | EXPORT_SYMBOL(ip_send_check); |