net/netfilter/ipvs/ip_vs_proto.c

   1 /*
   2  * ip_vs_proto.c: transport protocol load balancing support for IPVS
   3  *
   4  * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
   5  *              Julian Anastasov <ja@ssi.bg>
   6  *
   7  *              This program is free software; you can redistribute it and/or
   8  *              modify it under the terms of the GNU General Public License
   9  *              as published by the Free Software Foundation; either version
  10  *              2 of the License, or (at your option) any later version.
  11  *
  12  * Changes:
  13  *
  14  */
  15
  16 #define KMSG_COMPONENT "IPVS"
  17 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  18
  19 #include <linux/module.h>
  20 #include <linux/kernel.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/gfp.h>
  23 #include <linux/in.h>
  24 #include <linux/ip.h>
  25 #include <net/protocol.h>
  26 #include <net/tcp.h>
  27 #include <net/udp.h>
  28 #include <linux/stat.h>
  29 #include <linux/proc_fs.h>
  30
  31 #include <net/ip_vs.h>
  32
  33
  34 /*
  35  * IPVS protocols can only be registered/unregistered when the ipvs
  36  * module is loaded/unloaded, so no lock is needed in accessing the
  37  * ipvs protocol table.
  38  */
  39
  40 #define IP_VS_PROTO_TAB_SIZE            32      /* must be power of 2 */
  41 #define IP_VS_PROTO_HASH(proto)         ((proto) & (IP_VS_PROTO_TAB_SIZE-1))
  42
  43 static struct ip_vs_protocol *ip_vs_proto_table[IP_VS_PROTO_TAB_SIZE];
  44
  45
  46 /*
  47  *      register an ipvs protocol
  48  */
  49 static int __used __init register_ip_vs_protocol(struct ip_vs_protocol *pp)
  50 {
  51         unsigned int hash = IP_VS_PROTO_HASH(pp->protocol);
  52
  53         pp->next = ip_vs_proto_table[hash];
  54         ip_vs_proto_table[hash] = pp;
  55
  56         if (pp->init != NULL)
  57                 pp->init(pp);
  58
  59         return 0;
  60 }
  61
  62 /*
  63  *      register an ipvs protocols netns related data
  64  */
  65 static int
  66 register_ip_vs_proto_netns(struct net *net, struct ip_vs_protocol *pp)
  67 {
  68         struct netns_ipvs *ipvs = net_ipvs(net);
  69         unsigned int hash = IP_VS_PROTO_HASH(pp->protocol);
  70         struct ip_vs_proto_data *pd =
  71                         kzalloc(sizeof(struct ip_vs_proto_data), GFP_KERNEL);
  72
  73         if (!pd)
  74                 return -ENOMEM;
  75
  76         pd->pp = pp;    /* For speed issues */
  77         pd->next = ipvs->proto_data_table[hash];
  78         ipvs->proto_data_table[hash] = pd;
  79         atomic_set(&pd->appcnt, 0);     /* Init app counter */
  80
  81         if (pp->init_netns != NULL) {
  82                 int ret = pp->init_netns(net, pd);
  83                 if (ret) {
  84                         /* unlink an free proto data */
  85                         ipvs->proto_data_table[hash] = pd->next;
  86                         kfree(pd);
  87                         return ret;
  88                 }
  89         }
  90
  91         return 0;
  92 }
  93
  94 /*
  95  *      unregister an ipvs protocol
  96  */
  97 static int unregister_ip_vs_protocol(struct ip_vs_protocol *pp)
  98 {
  99         struct ip_vs_protocol **pp_p;
 100         unsigned int hash = IP_VS_PROTO_HASH(pp->protocol);
 101
 102         pp_p = &ip_vs_proto_table[hash];
 103         for (; *pp_p; pp_p = &(*pp_p)->next) {
 104                 if (*pp_p == pp) {
 105                         *pp_p = pp->next;
 106                         if (pp->exit != NULL)
 107                                 pp->exit(pp);
 108                         return 0;
 109                 }
 110         }
 111
 112         return -ESRCH;
 113 }
 114
 115 /*
 116  *      unregister an ipvs protocols netns data
 117  */
 118 static int
 119 unregister_ip_vs_proto_netns(struct net *net, struct ip_vs_proto_data *pd)
 120 {
 121         struct netns_ipvs *ipvs = net_ipvs(net);
 122         struct ip_vs_proto_data **pd_p;
 123         unsigned int hash = IP_VS_PROTO_HASH(pd->pp->protocol);
 124
 125         pd_p = &ipvs->proto_data_table[hash];
 126         for (; *pd_p; pd_p = &(*pd_p)->next) {
 127                 if (*pd_p == pd) {
 128                         *pd_p = pd->next;
 129                         if (pd->pp->exit_netns != NULL)
 130                                 pd->pp->exit_netns(net, pd);
 131                         kfree(pd);
 132                         return 0;
 133                 }
 134         }
 135
 136         return -ESRCH;
 137 }
 138
 139 /*
 140  *      get ip_vs_protocol object by its proto.
 141  */
 142 struct ip_vs_protocol * ip_vs_proto_get(unsigned short proto)
 143 {
 144         struct ip_vs_protocol *pp;
 145         unsigned int hash = IP_VS_PROTO_HASH(proto);
 146
 147         for (pp = ip_vs_proto_table[hash]; pp; pp = pp->next) {
 148                 if (pp->protocol == proto)
 149                         return pp;
 150         }
 151
 152         return NULL;
 153 }
 154 EXPORT_SYMBOL(ip_vs_proto_get);
 155
 156 /*
 157  *      get ip_vs_protocol object data by netns and proto
 158  */
 159 struct ip_vs_proto_data *
 160 ip_vs_proto_data_get(struct netns_ipvs *ipvs, unsigned short proto)
 161 {
 162         struct ip_vs_proto_data *pd;
 163         unsigned int hash = IP_VS_PROTO_HASH(proto);
 164
 165         for (pd = ipvs->proto_data_table[hash]; pd; pd = pd->next) {
 166                 if (pd->pp->protocol == proto)
 167                         return pd;
 168         }
 169
 170         return NULL;
 171 }
 172 EXPORT_SYMBOL(ip_vs_proto_data_get);
 173
 174 /*
 175  *      Propagate event for state change to all protocols
 176  */
 177 void ip_vs_protocol_timeout_change(struct netns_ipvs *ipvs, int flags)
 178 {
 179         struct ip_vs_proto_data *pd;
 180         int i;
 181
 182         for (i = 0; i < IP_VS_PROTO_TAB_SIZE; i++) {
 183                 for (pd = ipvs->proto_data_table[i]; pd; pd = pd->next) {
 184                         if (pd->pp->timeout_change)
 185                                 pd->pp->timeout_change(pd, flags);
 186                 }
 187         }
 188 }
 189
 190
 191 int *
 192 ip_vs_create_timeout_table(int *table, int size)
 193 {
 194         return kmemdup(table, size, GFP_KERNEL);
 195 }
 196
 197
 198 /*
 199  *      Set timeout value for state specified by name
 200  */
 201 int
 202 ip_vs_set_state_timeout(int *table, int num, const char *const *names,
 203                         const char *name, int to)
 204 {
 205         int i;
 206
 207         if (!table || !name || !to)
 208                 return -EINVAL;
 209
 210         for (i = 0; i < num; i++) {
 211                 if (strcmp(names[i], name))
 212                         continue;
 213                 table[i] = to * HZ;
 214                 return 0;
 215         }
 216         return -ENOENT;
 217 }
 218
 219
 220 const char * ip_vs_state_name(__u16 proto, int state)
 221 {
 222         struct ip_vs_protocol *pp = ip_vs_proto_get(proto);
 223
 224         if (pp == NULL || pp->state_name == NULL)
 225                 return (IPPROTO_IP == proto) ? "NONE" : "ERR!";
 226         return pp->state_name(state);
 227 }
 228
 229
 230 static void
 231 ip_vs_tcpudp_debug_packet_v4(struct ip_vs_protocol *pp,
 232                              const struct sk_buff *skb,
 233                              int offset,
 234                              const char *msg)
 235 {
 236         char buf[128];
 237         struct iphdr _iph, *ih;
 238
 239         ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
 240         if (ih == NULL)
 241                 sprintf(buf, "TRUNCATED");
 242         else if (ih->frag_off & htons(IP_OFFSET))
 243                 sprintf(buf, "%pI4->%pI4 frag", &ih->saddr, &ih->daddr);
 244         else {
 245                 __be16 _ports[2], *pptr;
 246
 247                 pptr = skb_header_pointer(skb, offset + ih->ihl*4,
 248                                           sizeof(_ports), _ports);
 249                 if (pptr == NULL)
 250                         sprintf(buf, "TRUNCATED %pI4->%pI4",
 251                                 &ih->saddr, &ih->daddr);
 252                 else
 253                         sprintf(buf, "%pI4:%u->%pI4:%u",
 254                                 &ih->saddr, ntohs(pptr[0]),
 255                                 &ih->daddr, ntohs(pptr[1]));
 256         }
 257
 258         pr_debug("%s: %s %s\n", msg, pp->name, buf);
 259 }
 260
 261 #ifdef CONFIG_IP_VS_IPV6
 262 static void
 263 ip_vs_tcpudp_debug_packet_v6(struct ip_vs_protocol *pp,
 264                              const struct sk_buff *skb,
 265                              int offset,
 266                              const char *msg)
 267 {
 268         char buf[192];
 269         struct ipv6hdr _iph, *ih;
 270
 271         ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
 272         if (ih == NULL)
 273                 sprintf(buf, "TRUNCATED");
 274         else if (ih->nexthdr == IPPROTO_FRAGMENT)
 275                 sprintf(buf, "%pI6c->%pI6c frag", &ih->saddr, &ih->daddr);
 276         else {
 277                 __be16 _ports[2], *pptr;
 278
 279                 pptr = skb_header_pointer(skb, offset + sizeof(struct ipv6hdr),
 280                                           sizeof(_ports), _ports);
 281                 if (pptr == NULL)
 282                         sprintf(buf, "TRUNCATED %pI6c->%pI6c",
 283                                 &ih->saddr, &ih->daddr);
 284                 else
 285                         sprintf(buf, "%pI6c:%u->%pI6c:%u",
 286                                 &ih->saddr, ntohs(pptr[0]),
 287                                 &ih->daddr, ntohs(pptr[1]));
 288         }
 289
 290         pr_debug("%s: %s %s\n", msg, pp->name, buf);
 291 }
 292 #endif
 293
 294
 295 void
 296 ip_vs_tcpudp_debug_packet(int af, struct ip_vs_protocol *pp,
 297                           const struct sk_buff *skb,
 298                           int offset,
 299                           const char *msg)
 300 {
 301 #ifdef CONFIG_IP_VS_IPV6
 302         if (af == AF_INET6)
 303                 ip_vs_tcpudp_debug_packet_v6(pp, skb, offset, msg);
 304         else
 305 #endif
 306                 ip_vs_tcpudp_debug_packet_v4(pp, skb, offset, msg);
 307 }
 308
 309 /*
 310  * per network name-space init
 311  */
 312 int __net_init ip_vs_protocol_net_init(struct net *net)
 313 {
 314         int i, ret;
 315         static struct ip_vs_protocol *protos[] = {
 316 #ifdef CONFIG_IP_VS_PROTO_TCP
 317         &ip_vs_protocol_tcp,
 318 #endif
 319 #ifdef CONFIG_IP_VS_PROTO_UDP
 320         &ip_vs_protocol_udp,
 321 #endif
 322 #ifdef CONFIG_IP_VS_PROTO_SCTP
 323         &ip_vs_protocol_sctp,
 324 #endif
 325 #ifdef CONFIG_IP_VS_PROTO_AH
 326         &ip_vs_protocol_ah,
 327 #endif
 328 #ifdef CONFIG_IP_VS_PROTO_ESP
 329         &ip_vs_protocol_esp,
 330 #endif
 331         };
 332
 333         for (i = 0; i < ARRAY_SIZE(protos); i++) {
 334                 ret = register_ip_vs_proto_netns(net, protos[i]);
 335                 if (ret < 0)
 336                         goto cleanup;
 337         }
 338         return 0;
 339
 340 cleanup:
 341         ip_vs_protocol_net_cleanup(net);
 342         return ret;
 343 }
 344
 345 void __net_exit ip_vs_protocol_net_cleanup(struct net *net)
 346 {
 347         struct netns_ipvs *ipvs = net_ipvs(net);
 348         struct ip_vs_proto_data *pd;
 349         int i;
 350
 351         /* unregister all the ipvs proto data for this netns */
 352         for (i = 0; i < IP_VS_PROTO_TAB_SIZE; i++) {
 353                 while ((pd = ipvs->proto_data_table[i]) != NULL)
 354                         unregister_ip_vs_proto_netns(net, pd);
 355         }
 356 }
 357
 358 int __init ip_vs_protocol_init(void)
 359 {
 360         char protocols[64];
 361 #define REGISTER_PROTOCOL(p)                    \
 362         do {                                    \
 363                 register_ip_vs_protocol(p);     \
 364                 strcat(protocols, ", ");        \
 365                 strcat(protocols, (p)->name);   \
 366         } while (0)
 367
 368         protocols[0] = '\0';
 369         protocols[2] = '\0';
 370 #ifdef CONFIG_IP_VS_PROTO_TCP
 371         REGISTER_PROTOCOL(&ip_vs_protocol_tcp);
 372 #endif
 373 #ifdef CONFIG_IP_VS_PROTO_UDP
 374         REGISTER_PROTOCOL(&ip_vs_protocol_udp);
 375 #endif
 376 #ifdef CONFIG_IP_VS_PROTO_SCTP
 377         REGISTER_PROTOCOL(&ip_vs_protocol_sctp);
 378 #endif
 379 #ifdef CONFIG_IP_VS_PROTO_AH
 380         REGISTER_PROTOCOL(&ip_vs_protocol_ah);
 381 #endif
 382 #ifdef CONFIG_IP_VS_PROTO_ESP
 383         REGISTER_PROTOCOL(&ip_vs_protocol_esp);
 384 #endif
 385         pr_info("Registered protocols (%s)\n", &protocols[2]);
 386
 387         return 0;
 388 }
 389
 390
 391 void ip_vs_protocol_cleanup(void)
 392 {
 393         struct ip_vs_protocol *pp;
 394         int i;
 395
 396         /* unregister all the ipvs protocols */
 397         for (i = 0; i < IP_VS_PROTO_TAB_SIZE; i++) {
 398                 while ((pp = ip_vs_proto_table[i]) != NULL)
 399                         unregister_ip_vs_protocol(pp);
 400         }
 401 }