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 <asm/system.h>
  29 #include <linux/stat.h>
  30 #include <linux/proc_fs.h>
  31
  32 #include <net/ip_vs.h>
  33
  34
  35 /*
  36  * IPVS protocols can only be registered/unregistered when the ipvs
  37  * module is loaded/unloaded, so no lock is needed in accessing the
  38  * ipvs protocol table.
  39  */
  40
  41 #define IP_VS_PROTO_TAB_SIZE            32      /* must be power of 2 */
  42 #define IP_VS_PROTO_HASH(proto)         ((proto) & (IP_VS_PROTO_TAB_SIZE-1))
  43
  44 static struct ip_vs_protocol *ip_vs_proto_table[IP_VS_PROTO_TAB_SIZE];
  45
  46
  47 /*
  48  *      register an ipvs protocol
  49  */
  50 static int __used __init register_ip_vs_protocol(struct ip_vs_protocol *pp)
  51 {
  52         unsigned hash = IP_VS_PROTO_HASH(pp->protocol);
  53
  54         pp->next = ip_vs_proto_table[hash];
  55         ip_vs_proto_table[hash] = pp;
  56
  57         if (pp->init != NULL)
  58                 pp->init(pp);
  59
  60         return 0;
  61 }
  62
  63
  64 /*
  65  *      unregister an ipvs protocol
  66  */
  67 static int unregister_ip_vs_protocol(struct ip_vs_protocol *pp)
  68 {
  69         struct ip_vs_protocol **pp_p;
  70         unsigned hash = IP_VS_PROTO_HASH(pp->protocol);
  71
  72         pp_p = &ip_vs_proto_table[hash];
  73         for (; *pp_p; pp_p = &(*pp_p)->next) {
  74                 if (*pp_p == pp) {
  75                         *pp_p = pp->next;
  76                         if (pp->exit != NULL)
  77                                 pp->exit(pp);
  78                         return 0;
  79                 }
  80         }
  81
  82         return -ESRCH;
  83 }
  84
  85
  86 /*
  87  *      get ip_vs_protocol object by its proto.
  88  */
  89 struct ip_vs_protocol * ip_vs_proto_get(unsigned short proto)
  90 {
  91         struct ip_vs_protocol *pp;
  92         unsigned hash = IP_VS_PROTO_HASH(proto);
  93
  94         for (pp = ip_vs_proto_table[hash]; pp; pp = pp->next) {
  95                 if (pp->protocol == proto)
  96                         return pp;
  97         }
  98
  99         return NULL;
 100 }
 101
 102
 103 /*
 104  *      Propagate event for state change to all protocols
 105  */
 106 void ip_vs_protocol_timeout_change(int flags)
 107 {
 108         struct ip_vs_protocol *pp;
 109         int i;
 110
 111         for (i = 0; i < IP_VS_PROTO_TAB_SIZE; i++) {
 112                 for (pp = ip_vs_proto_table[i]; pp; pp = pp->next) {
 113                         if (pp->timeout_change)
 114                                 pp->timeout_change(pp, flags);
 115                 }
 116         }
 117 }
 118
 119
 120 int *
 121 ip_vs_create_timeout_table(int *table, int size)
 122 {
 123         return kmemdup(table, size, GFP_ATOMIC);
 124 }
 125
 126
 127 /*
 128  *      Set timeout value for state specified by name
 129  */
 130 int
 131 ip_vs_set_state_timeout(int *table, int num, const char *const *names,
 132                         const char *name, int to)
 133 {
 134         int i;
 135
 136         if (!table || !name || !to)
 137                 return -EINVAL;
 138
 139         for (i = 0; i < num; i++) {
 140                 if (strcmp(names[i], name))
 141                         continue;
 142                 table[i] = to * HZ;
 143                 return 0;
 144         }
 145         return -ENOENT;
 146 }
 147
 148
 149 const char * ip_vs_state_name(__u16 proto, int state)
 150 {
 151         struct ip_vs_protocol *pp = ip_vs_proto_get(proto);
 152
 153         if (pp == NULL || pp->state_name == NULL)
 154                 return (IPPROTO_IP == proto) ? "NONE" : "ERR!";
 155         return pp->state_name(state);
 156 }
 157
 158
 159 static void
 160 ip_vs_tcpudp_debug_packet_v4(struct ip_vs_protocol *pp,
 161                              const struct sk_buff *skb,
 162                              int offset,
 163                              const char *msg)
 164 {
 165         char buf[128];
 166         struct iphdr _iph, *ih;
 167
 168         ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
 169         if (ih == NULL)
 170                 sprintf(buf, "%s TRUNCATED", pp->name);
 171         else if (ih->frag_off & htons(IP_OFFSET))
 172                 sprintf(buf, "%s %pI4->%pI4 frag",
 173                         pp->name, &ih->saddr, &ih->daddr);
 174         else {
 175                 __be16 _ports[2], *pptr
 176 ;
 177                 pptr = skb_header_pointer(skb, offset + ih->ihl*4,
 178                                           sizeof(_ports), _ports);
 179                 if (pptr == NULL)
 180                         sprintf(buf, "%s TRUNCATED %pI4->%pI4",
 181                                 pp->name, &ih->saddr, &ih->daddr);
 182                 else
 183                         sprintf(buf, "%s %pI4:%u->%pI4:%u",
 184                                 pp->name,
 185                                 &ih->saddr, ntohs(pptr[0]),
 186                                 &ih->daddr, ntohs(pptr[1]));
 187         }
 188
 189         pr_debug("%s: %s\n", msg, buf);
 190 }
 191
 192 #ifdef CONFIG_IP_VS_IPV6
 193 static void
 194 ip_vs_tcpudp_debug_packet_v6(struct ip_vs_protocol *pp,
 195                              const struct sk_buff *skb,
 196                              int offset,
 197                              const char *msg)
 198 {
 199         char buf[192];
 200         struct ipv6hdr _iph, *ih;
 201
 202         ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
 203         if (ih == NULL)
 204                 sprintf(buf, "%s TRUNCATED", pp->name);
 205         else if (ih->nexthdr == IPPROTO_FRAGMENT)
 206                 sprintf(buf, "%s %pI6->%pI6 frag",
 207                         pp->name, &ih->saddr, &ih->daddr);
 208         else {
 209                 __be16 _ports[2], *pptr;
 210
 211                 pptr = skb_header_pointer(skb, offset + sizeof(struct ipv6hdr),
 212                                           sizeof(_ports), _ports);
 213                 if (pptr == NULL)
 214                         sprintf(buf, "%s TRUNCATED %pI6->%pI6",
 215                                 pp->name, &ih->saddr, &ih->daddr);
 216                 else
 217                         sprintf(buf, "%s %pI6:%u->%pI6:%u",
 218                                 pp->name,
 219                                 &ih->saddr, ntohs(pptr[0]),
 220                                 &ih->daddr, ntohs(pptr[1]));
 221         }
 222
 223         pr_debug("%s: %s\n", msg, buf);
 224 }
 225 #endif
 226
 227
 228 void
 229 ip_vs_tcpudp_debug_packet(struct ip_vs_protocol *pp,
 230                           const struct sk_buff *skb,
 231                           int offset,
 232                           const char *msg)
 233 {
 234 #ifdef CONFIG_IP_VS_IPV6
 235         if (skb->protocol == htons(ETH_P_IPV6))
 236                 ip_vs_tcpudp_debug_packet_v6(pp, skb, offset, msg);
 237         else
 238 #endif
 239                 ip_vs_tcpudp_debug_packet_v4(pp, skb, offset, msg);
 240 }
 241
 242
 243 int __init ip_vs_protocol_init(void)
 244 {
 245         char protocols[64];
 246 #define REGISTER_PROTOCOL(p)                    \
 247         do {                                    \
 248                 register_ip_vs_protocol(p);     \
 249                 strcat(protocols, ", ");        \
 250                 strcat(protocols, (p)->name);   \
 251         } while (0)
 252
 253         protocols[0] = '\0';
 254         protocols[2] = '\0';
 255 #ifdef CONFIG_IP_VS_PROTO_TCP
 256         REGISTER_PROTOCOL(&ip_vs_protocol_tcp);
 257 #endif
 258 #ifdef CONFIG_IP_VS_PROTO_UDP
 259         REGISTER_PROTOCOL(&ip_vs_protocol_udp);
 260 #endif
 261 #ifdef CONFIG_IP_VS_PROTO_SCTP
 262         REGISTER_PROTOCOL(&ip_vs_protocol_sctp);
 263 #endif
 264 #ifdef CONFIG_IP_VS_PROTO_AH
 265         REGISTER_PROTOCOL(&ip_vs_protocol_ah);
 266 #endif
 267 #ifdef CONFIG_IP_VS_PROTO_ESP
 268         REGISTER_PROTOCOL(&ip_vs_protocol_esp);
 269 #endif
 270         pr_info("Registered protocols (%s)\n", &protocols[2]);
 271
 272         return 0;
 273 }
 274
 275
 276 void ip_vs_protocol_cleanup(void)
 277 {
 278         struct ip_vs_protocol *pp;
 279         int i;
 280
 281         /* unregister all the ipvs protocols */
 282         for (i = 0; i < IP_VS_PROTO_TAB_SIZE; i++) {
 283                 while ((pp = ip_vs_proto_table[i]) != NULL)
 284                         unregister_ip_vs_protocol(pp);
 285         }
 286 }