linux/net/netfilter/ipvs/ip_vs_proto.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * ip_vs_proto.c: transport protocol load balancing support for IPVS
   4 *
   5 * Authors:     Wensong Zhang <wensong@linuxvirtualserver.org>
   6 *              Julian Anastasov <ja@ssi.bg>
   7 *
   8 * Changes:
   9 */
  10
  11#define KMSG_COMPONENT "IPVS"
  12#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14#include <linux/module.h>
  15#include <linux/kernel.h>
  16#include <linux/skbuff.h>
  17#include <linux/gfp.h>
  18#include <linux/in.h>
  19#include <linux/ip.h>
  20#include <net/protocol.h>
  21#include <net/tcp.h>
  22#include <net/udp.h>
  23#include <linux/stat.h>
  24#include <linux/proc_fs.h>
  25
  26#include <net/ip_vs.h>
  27
  28
  29/*
  30 * IPVS protocols can only be registered/unregistered when the ipvs
  31 * module is loaded/unloaded, so no lock is needed in accessing the
  32 * ipvs protocol table.
  33 */
  34
  35#define IP_VS_PROTO_TAB_SIZE            32      /* must be power of 2 */
  36#define IP_VS_PROTO_HASH(proto)         ((proto) & (IP_VS_PROTO_TAB_SIZE-1))
  37
  38static struct ip_vs_protocol *ip_vs_proto_table[IP_VS_PROTO_TAB_SIZE];
  39
  40/* States for conn templates: NONE or words separated with ",", max 15 chars */
  41static const char *ip_vs_ctpl_state_name_table[IP_VS_CTPL_S_LAST] = {
  42        [IP_VS_CTPL_S_NONE]                     = "NONE",
  43        [IP_VS_CTPL_S_ASSURED]                  = "ASSURED",
  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 netns_ipvs *ipvs, struct ip_vs_protocol *pp)
  67{
  68        unsigned int hash = IP_VS_PROTO_HASH(pp->protocol);
  69        struct ip_vs_proto_data *pd =
  70                        kzalloc(sizeof(struct ip_vs_proto_data), GFP_KERNEL);
  71
  72        if (!pd)
  73                return -ENOMEM;
  74
  75        pd->pp = pp;    /* For speed issues */
  76        pd->next = ipvs->proto_data_table[hash];
  77        ipvs->proto_data_table[hash] = pd;
  78        atomic_set(&pd->appcnt, 0);     /* Init app counter */
  79
  80        if (pp->init_netns != NULL) {
  81                int ret = pp->init_netns(ipvs, pd);
  82                if (ret) {
  83                        /* unlink an free proto data */
  84                        ipvs->proto_data_table[hash] = pd->next;
  85                        kfree(pd);
  86                        return ret;
  87                }
  88        }
  89
  90        return 0;
  91}
  92
  93/*
  94 *      unregister an ipvs protocol
  95 */
  96static int unregister_ip_vs_protocol(struct ip_vs_protocol *pp)
  97{
  98        struct ip_vs_protocol **pp_p;
  99        unsigned int hash = IP_VS_PROTO_HASH(pp->protocol);
 100
 101        pp_p = &ip_vs_proto_table[hash];
 102        for (; *pp_p; pp_p = &(*pp_p)->next) {
 103                if (*pp_p == pp) {
 104                        *pp_p = pp->next;
 105                        if (pp->exit != NULL)
 106                                pp->exit(pp);
 107                        return 0;
 108                }
 109        }
 110
 111        return -ESRCH;
 112}
 113
 114/*
 115 *      unregister an ipvs protocols netns data
 116 */
 117static int
 118unregister_ip_vs_proto_netns(struct netns_ipvs *ipvs, struct ip_vs_proto_data *pd)
 119{
 120        struct ip_vs_proto_data **pd_p;
 121        unsigned int hash = IP_VS_PROTO_HASH(pd->pp->protocol);
 122
 123        pd_p = &ipvs->proto_data_table[hash];
 124        for (; *pd_p; pd_p = &(*pd_p)->next) {
 125                if (*pd_p == pd) {
 126                        *pd_p = pd->next;
 127                        if (pd->pp->exit_netns != NULL)
 128                                pd->pp->exit_netns(ipvs, pd);
 129                        kfree(pd);
 130                        return 0;
 131                }
 132        }
 133
 134        return -ESRCH;
 135}
 136
 137/*
 138 *      get ip_vs_protocol object by its proto.
 139 */
 140struct ip_vs_protocol * ip_vs_proto_get(unsigned short proto)
 141{
 142        struct ip_vs_protocol *pp;
 143        unsigned int hash = IP_VS_PROTO_HASH(proto);
 144
 145        for (pp = ip_vs_proto_table[hash]; pp; pp = pp->next) {
 146                if (pp->protocol == proto)
 147                        return pp;
 148        }
 149
 150        return NULL;
 151}
 152EXPORT_SYMBOL(ip_vs_proto_get);
 153
 154/*
 155 *      get ip_vs_protocol object data by netns and proto
 156 */
 157struct ip_vs_proto_data *
 158ip_vs_proto_data_get(struct netns_ipvs *ipvs, unsigned short proto)
 159{
 160        struct ip_vs_proto_data *pd;
 161        unsigned int hash = IP_VS_PROTO_HASH(proto);
 162
 163        for (pd = ipvs->proto_data_table[hash]; pd; pd = pd->next) {
 164                if (pd->pp->protocol == proto)
 165                        return pd;
 166        }
 167
 168        return NULL;
 169}
 170EXPORT_SYMBOL(ip_vs_proto_data_get);
 171
 172/*
 173 *      Propagate event for state change to all protocols
 174 */
 175void ip_vs_protocol_timeout_change(struct netns_ipvs *ipvs, int flags)
 176{
 177        struct ip_vs_proto_data *pd;
 178        int i;
 179
 180        for (i = 0; i < IP_VS_PROTO_TAB_SIZE; i++) {
 181                for (pd = ipvs->proto_data_table[i]; pd; pd = pd->next) {
 182                        if (pd->pp->timeout_change)
 183                                pd->pp->timeout_change(pd, flags);
 184                }
 185        }
 186}
 187
 188
 189int *
 190ip_vs_create_timeout_table(int *table, int size)
 191{
 192        return kmemdup(table, size, GFP_KERNEL);
 193}
 194
 195
 196const char *ip_vs_state_name(const struct ip_vs_conn *cp)
 197{
 198        unsigned int state = cp->state;
 199        struct ip_vs_protocol *pp;
 200
 201        if (cp->flags & IP_VS_CONN_F_TEMPLATE) {
 202
 203                if (state >= IP_VS_CTPL_S_LAST)
 204                        return "ERR!";
 205                return ip_vs_ctpl_state_name_table[state] ? : "?";
 206        }
 207        pp = ip_vs_proto_get(cp->protocol);
 208        if (pp == NULL || pp->state_name == NULL)
 209                return (cp->protocol == IPPROTO_IP) ? "NONE" : "ERR!";
 210        return pp->state_name(state);
 211}
 212
 213
 214static void
 215ip_vs_tcpudp_debug_packet_v4(struct ip_vs_protocol *pp,
 216                             const struct sk_buff *skb,
 217                             int offset,
 218                             const char *msg)
 219{
 220        char buf[128];
 221        struct iphdr _iph, *ih;
 222
 223        ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
 224        if (ih == NULL)
 225                sprintf(buf, "TRUNCATED");
 226        else if (ih->frag_off & htons(IP_OFFSET))
 227                sprintf(buf, "%pI4->%pI4 frag", &ih->saddr, &ih->daddr);
 228        else {
 229                __be16 _ports[2], *pptr;
 230
 231                pptr = skb_header_pointer(skb, offset + ih->ihl*4,
 232                                          sizeof(_ports), _ports);
 233                if (pptr == NULL)
 234                        sprintf(buf, "TRUNCATED %pI4->%pI4",
 235                                &ih->saddr, &ih->daddr);
 236                else
 237                        sprintf(buf, "%pI4:%u->%pI4:%u",
 238                                &ih->saddr, ntohs(pptr[0]),
 239                                &ih->daddr, ntohs(pptr[1]));
 240        }
 241
 242        pr_debug("%s: %s %s\n", msg, pp->name, buf);
 243}
 244
 245#ifdef CONFIG_IP_VS_IPV6
 246static void
 247ip_vs_tcpudp_debug_packet_v6(struct ip_vs_protocol *pp,
 248                             const struct sk_buff *skb,
 249                             int offset,
 250                             const char *msg)
 251{
 252        char buf[192];
 253        struct ipv6hdr _iph, *ih;
 254
 255        ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
 256        if (ih == NULL)
 257                sprintf(buf, "TRUNCATED");
 258        else if (ih->nexthdr == IPPROTO_FRAGMENT)
 259                sprintf(buf, "%pI6c->%pI6c frag", &ih->saddr, &ih->daddr);
 260        else {
 261                __be16 _ports[2], *pptr;
 262
 263                pptr = skb_header_pointer(skb, offset + sizeof(struct ipv6hdr),
 264                                          sizeof(_ports), _ports);
 265                if (pptr == NULL)
 266                        sprintf(buf, "TRUNCATED %pI6c->%pI6c",
 267                                &ih->saddr, &ih->daddr);
 268                else
 269                        sprintf(buf, "%pI6c:%u->%pI6c:%u",
 270                                &ih->saddr, ntohs(pptr[0]),
 271                                &ih->daddr, ntohs(pptr[1]));
 272        }
 273
 274        pr_debug("%s: %s %s\n", msg, pp->name, buf);
 275}
 276#endif
 277
 278
 279void
 280ip_vs_tcpudp_debug_packet(int af, struct ip_vs_protocol *pp,
 281                          const struct sk_buff *skb,
 282                          int offset,
 283                          const char *msg)
 284{
 285#ifdef CONFIG_IP_VS_IPV6
 286        if (af == AF_INET6)
 287                ip_vs_tcpudp_debug_packet_v6(pp, skb, offset, msg);
 288        else
 289#endif
 290                ip_vs_tcpudp_debug_packet_v4(pp, skb, offset, msg);
 291}
 292
 293/*
 294 * per network name-space init
 295 */
 296int __net_init ip_vs_protocol_net_init(struct netns_ipvs *ipvs)
 297{
 298        int i, ret;
 299        static struct ip_vs_protocol *protos[] = {
 300#ifdef CONFIG_IP_VS_PROTO_TCP
 301        &ip_vs_protocol_tcp,
 302#endif
 303#ifdef CONFIG_IP_VS_PROTO_UDP
 304        &ip_vs_protocol_udp,
 305#endif
 306#ifdef CONFIG_IP_VS_PROTO_SCTP
 307        &ip_vs_protocol_sctp,
 308#endif
 309#ifdef CONFIG_IP_VS_PROTO_AH
 310        &ip_vs_protocol_ah,
 311#endif
 312#ifdef CONFIG_IP_VS_PROTO_ESP
 313        &ip_vs_protocol_esp,
 314#endif
 315        };
 316
 317        for (i = 0; i < ARRAY_SIZE(protos); i++) {
 318                ret = register_ip_vs_proto_netns(ipvs, protos[i]);
 319                if (ret < 0)
 320                        goto cleanup;
 321        }
 322        return 0;
 323
 324cleanup:
 325        ip_vs_protocol_net_cleanup(ipvs);
 326        return ret;
 327}
 328
 329void __net_exit ip_vs_protocol_net_cleanup(struct netns_ipvs *ipvs)
 330{
 331        struct ip_vs_proto_data *pd;
 332        int i;
 333
 334        /* unregister all the ipvs proto data for this netns */
 335        for (i = 0; i < IP_VS_PROTO_TAB_SIZE; i++) {
 336                while ((pd = ipvs->proto_data_table[i]) != NULL)
 337                        unregister_ip_vs_proto_netns(ipvs, pd);
 338        }
 339}
 340
 341int __init ip_vs_protocol_init(void)
 342{
 343        char protocols[64];
 344#define REGISTER_PROTOCOL(p)                    \
 345        do {                                    \
 346                register_ip_vs_protocol(p);     \
 347                strcat(protocols, ", ");        \
 348                strcat(protocols, (p)->name);   \
 349        } while (0)
 350
 351        protocols[0] = '\0';
 352        protocols[2] = '\0';
 353#ifdef CONFIG_IP_VS_PROTO_TCP
 354        REGISTER_PROTOCOL(&ip_vs_protocol_tcp);
 355#endif
 356#ifdef CONFIG_IP_VS_PROTO_UDP
 357        REGISTER_PROTOCOL(&ip_vs_protocol_udp);
 358#endif
 359#ifdef CONFIG_IP_VS_PROTO_SCTP
 360        REGISTER_PROTOCOL(&ip_vs_protocol_sctp);
 361#endif
 362#ifdef CONFIG_IP_VS_PROTO_AH
 363        REGISTER_PROTOCOL(&ip_vs_protocol_ah);
 364#endif
 365#ifdef CONFIG_IP_VS_PROTO_ESP
 366        REGISTER_PROTOCOL(&ip_vs_protocol_esp);
 367#endif
 368        pr_info("Registered protocols (%s)\n", &protocols[2]);
 369
 370        return 0;
 371}
 372
 373
 374void ip_vs_protocol_cleanup(void)
 375{
 376        struct ip_vs_protocol *pp;
 377        int i;
 378
 379        /* unregister all the ipvs protocols */
 380        for (i = 0; i < IP_VS_PROTO_TAB_SIZE; i++) {
 381                while ((pp = ip_vs_proto_table[i]) != NULL)
 382                        unregister_ip_vs_protocol(pp);
 383        }
 384}
 385