linux/net/netfilter/ipvs/ip_vs_proto.c
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   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
  43static struct ip_vs_protocol *ip_vs_proto_table[IP_VS_PROTO_TAB_SIZE];
  44
  45
  46/*
  47 *      register an ipvs protocol
  48 */
  49static 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 */
  65static int
  66register_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 */
  97static 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 */
 118static int
 119unregister_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 */
 142struct 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}
 154EXPORT_SYMBOL(ip_vs_proto_get);
 155
 156/*
 157 *      get ip_vs_protocol object data by netns and proto
 158 */
 159static struct ip_vs_proto_data *
 160__ipvs_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
 173struct ip_vs_proto_data *
 174ip_vs_proto_data_get(struct net *net, unsigned short proto)
 175{
 176        struct netns_ipvs *ipvs = net_ipvs(net);
 177
 178        return __ipvs_proto_data_get(ipvs, proto);
 179}
 180EXPORT_SYMBOL(ip_vs_proto_data_get);
 181
 182/*
 183 *      Propagate event for state change to all protocols
 184 */
 185void ip_vs_protocol_timeout_change(struct netns_ipvs *ipvs, int flags)
 186{
 187        struct ip_vs_proto_data *pd;
 188        int i;
 189
 190        for (i = 0; i < IP_VS_PROTO_TAB_SIZE; i++) {
 191                for (pd = ipvs->proto_data_table[i]; pd; pd = pd->next) {
 192                        if (pd->pp->timeout_change)
 193                                pd->pp->timeout_change(pd, flags);
 194                }
 195        }
 196}
 197
 198
 199int *
 200ip_vs_create_timeout_table(int *table, int size)
 201{
 202        return kmemdup(table, size, GFP_KERNEL);
 203}
 204
 205
 206/*
 207 *      Set timeout value for state specified by name
 208 */
 209int
 210ip_vs_set_state_timeout(int *table, int num, const char *const *names,
 211                        const char *name, int to)
 212{
 213        int i;
 214
 215        if (!table || !name || !to)
 216                return -EINVAL;
 217
 218        for (i = 0; i < num; i++) {
 219                if (strcmp(names[i], name))
 220                        continue;
 221                table[i] = to * HZ;
 222                return 0;
 223        }
 224        return -ENOENT;
 225}
 226
 227
 228const char * ip_vs_state_name(__u16 proto, int state)
 229{
 230        struct ip_vs_protocol *pp = ip_vs_proto_get(proto);
 231
 232        if (pp == NULL || pp->state_name == NULL)
 233                return (IPPROTO_IP == proto) ? "NONE" : "ERR!";
 234        return pp->state_name(state);
 235}
 236
 237
 238static void
 239ip_vs_tcpudp_debug_packet_v4(struct ip_vs_protocol *pp,
 240                             const struct sk_buff *skb,
 241                             int offset,
 242                             const char *msg)
 243{
 244        char buf[128];
 245        struct iphdr _iph, *ih;
 246
 247        ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
 248        if (ih == NULL)
 249                sprintf(buf, "TRUNCATED");
 250        else if (ih->frag_off & htons(IP_OFFSET))
 251                sprintf(buf, "%pI4->%pI4 frag", &ih->saddr, &ih->daddr);
 252        else {
 253                __be16 _ports[2], *pptr;
 254
 255                pptr = skb_header_pointer(skb, offset + ih->ihl*4,
 256                                          sizeof(_ports), _ports);
 257                if (pptr == NULL)
 258                        sprintf(buf, "TRUNCATED %pI4->%pI4",
 259                                &ih->saddr, &ih->daddr);
 260                else
 261                        sprintf(buf, "%pI4:%u->%pI4:%u",
 262                                &ih->saddr, ntohs(pptr[0]),
 263                                &ih->daddr, ntohs(pptr[1]));
 264        }
 265
 266        pr_debug("%s: %s %s\n", msg, pp->name, buf);
 267}
 268
 269#ifdef CONFIG_IP_VS_IPV6
 270static void
 271ip_vs_tcpudp_debug_packet_v6(struct ip_vs_protocol *pp,
 272                             const struct sk_buff *skb,
 273                             int offset,
 274                             const char *msg)
 275{
 276        char buf[192];
 277        struct ipv6hdr _iph, *ih;
 278
 279        ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
 280        if (ih == NULL)
 281                sprintf(buf, "TRUNCATED");
 282        else if (ih->nexthdr == IPPROTO_FRAGMENT)
 283                sprintf(buf, "%pI6c->%pI6c frag", &ih->saddr, &ih->daddr);
 284        else {
 285                __be16 _ports[2], *pptr;
 286
 287                pptr = skb_header_pointer(skb, offset + sizeof(struct ipv6hdr),
 288                                          sizeof(_ports), _ports);
 289                if (pptr == NULL)
 290                        sprintf(buf, "TRUNCATED %pI6c->%pI6c",
 291                                &ih->saddr, &ih->daddr);
 292                else
 293                        sprintf(buf, "%pI6c:%u->%pI6c:%u",
 294                                &ih->saddr, ntohs(pptr[0]),
 295                                &ih->daddr, ntohs(pptr[1]));
 296        }
 297
 298        pr_debug("%s: %s %s\n", msg, pp->name, buf);
 299}
 300#endif
 301
 302
 303void
 304ip_vs_tcpudp_debug_packet(int af, struct ip_vs_protocol *pp,
 305                          const struct sk_buff *skb,
 306                          int offset,
 307                          const char *msg)
 308{
 309#ifdef CONFIG_IP_VS_IPV6
 310        if (af == AF_INET6)
 311                ip_vs_tcpudp_debug_packet_v6(pp, skb, offset, msg);
 312        else
 313#endif
 314                ip_vs_tcpudp_debug_packet_v4(pp, skb, offset, msg);
 315}
 316
 317/*
 318 * per network name-space init
 319 */
 320int __net_init ip_vs_protocol_net_init(struct net *net)
 321{
 322        int i, ret;
 323        static struct ip_vs_protocol *protos[] = {
 324#ifdef CONFIG_IP_VS_PROTO_TCP
 325        &ip_vs_protocol_tcp,
 326#endif
 327#ifdef CONFIG_IP_VS_PROTO_UDP
 328        &ip_vs_protocol_udp,
 329#endif
 330#ifdef CONFIG_IP_VS_PROTO_SCTP
 331        &ip_vs_protocol_sctp,
 332#endif
 333#ifdef CONFIG_IP_VS_PROTO_AH
 334        &ip_vs_protocol_ah,
 335#endif
 336#ifdef CONFIG_IP_VS_PROTO_ESP
 337        &ip_vs_protocol_esp,
 338#endif
 339        };
 340
 341        for (i = 0; i < ARRAY_SIZE(protos); i++) {
 342                ret = register_ip_vs_proto_netns(net, protos[i]);
 343                if (ret < 0)
 344                        goto cleanup;
 345        }
 346        return 0;
 347
 348cleanup:
 349        ip_vs_protocol_net_cleanup(net);
 350        return ret;
 351}
 352
 353void __net_exit ip_vs_protocol_net_cleanup(struct net *net)
 354{
 355        struct netns_ipvs *ipvs = net_ipvs(net);
 356        struct ip_vs_proto_data *pd;
 357        int i;
 358
 359        /* unregister all the ipvs proto data for this netns */
 360        for (i = 0; i < IP_VS_PROTO_TAB_SIZE; i++) {
 361                while ((pd = ipvs->proto_data_table[i]) != NULL)
 362                        unregister_ip_vs_proto_netns(net, pd);
 363        }
 364}
 365
 366int __init ip_vs_protocol_init(void)
 367{
 368        char protocols[64];
 369#define REGISTER_PROTOCOL(p)                    \
 370        do {                                    \
 371                register_ip_vs_protocol(p);     \
 372                strcat(protocols, ", ");        \
 373                strcat(protocols, (p)->name);   \
 374        } while (0)
 375
 376        protocols[0] = '\0';
 377        protocols[2] = '\0';
 378#ifdef CONFIG_IP_VS_PROTO_TCP
 379        REGISTER_PROTOCOL(&ip_vs_protocol_tcp);
 380#endif
 381#ifdef CONFIG_IP_VS_PROTO_UDP
 382        REGISTER_PROTOCOL(&ip_vs_protocol_udp);
 383#endif
 384#ifdef CONFIG_IP_VS_PROTO_SCTP
 385        REGISTER_PROTOCOL(&ip_vs_protocol_sctp);
 386#endif
 387#ifdef CONFIG_IP_VS_PROTO_AH
 388        REGISTER_PROTOCOL(&ip_vs_protocol_ah);
 389#endif
 390#ifdef CONFIG_IP_VS_PROTO_ESP
 391        REGISTER_PROTOCOL(&ip_vs_protocol_esp);
 392#endif
 393        pr_info("Registered protocols (%s)\n", &protocols[2]);
 394
 395        return 0;
 396}
 397
 398
 399void ip_vs_protocol_cleanup(void)
 400{
 401        struct ip_vs_protocol *pp;
 402        int i;
 403
 404        /* unregister all the ipvs protocols */
 405        for (i = 0; i < IP_VS_PROTO_TAB_SIZE; i++) {
 406                while ((pp = ip_vs_proto_table[i]) != NULL)
 407                        unregister_ip_vs_protocol(pp);
 408        }
 409}
 410