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 #include <linux/module.h>
  17 #include <linux/kernel.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/in.h>
  20 #include <linux/ip.h>
  21 #include <net/protocol.h>
  22 #include <net/tcp.h>
  23 #include <net/udp.h>
  24 #include <asm/system.h>
  25 #include <linux/stat.h>
  26 #include <linux/proc_fs.h>
  27
  28 #include <net/ip_vs.h>
  29
  30
  31 /*
  32  * IPVS protocols can only be registered/unregistered when the ipvs
  33  * module is loaded/unloaded, so no lock is needed in accessing the
  34  * ipvs protocol table.
  35  */
  36
  37 #define IP_VS_PROTO_TAB_SIZE            32      /* must be power of 2 */
  38 #define IP_VS_PROTO_HASH(proto)         ((proto) & (IP_VS_PROTO_TAB_SIZE-1))
  39
  40 static struct ip_vs_protocol *ip_vs_proto_table[IP_VS_PROTO_TAB_SIZE];
  41
  42
  43 /*
  44  *      register an ipvs protocol
  45  */
  46 static int __used __init register_ip_vs_protocol(struct ip_vs_protocol *pp)
  47 {
  48         unsigned hash = IP_VS_PROTO_HASH(pp->protocol);
  49
  50         pp->next = ip_vs_proto_table[hash];
  51         ip_vs_proto_table[hash] = pp;
  52
  53         if (pp->init != NULL)
  54                 pp->init(pp);
  55
  56         return 0;
  57 }
  58
  59
  60 /*
  61  *      unregister an ipvs protocol
  62  */
  63 static int unregister_ip_vs_protocol(struct ip_vs_protocol *pp)
  64 {
  65         struct ip_vs_protocol **pp_p;
  66         unsigned hash = IP_VS_PROTO_HASH(pp->protocol);
  67
  68         pp_p = &ip_vs_proto_table[hash];
  69         for (; *pp_p; pp_p = &(*pp_p)->next) {
  70                 if (*pp_p == pp) {
  71                         *pp_p = pp->next;
  72                         if (pp->exit != NULL)
  73                                 pp->exit(pp);
  74                         return 0;
  75                 }
  76         }
  77
  78         return -ESRCH;
  79 }
  80
  81
  82 /*
  83  *      get ip_vs_protocol object by its proto.
  84  */
  85 struct ip_vs_protocol * ip_vs_proto_get(unsigned short proto)
  86 {
  87         struct ip_vs_protocol *pp;
  88         unsigned hash = IP_VS_PROTO_HASH(proto);
  89
  90         for (pp = ip_vs_proto_table[hash]; pp; pp = pp->next) {
  91                 if (pp->protocol == proto)
  92                         return pp;
  93         }
  94
  95         return NULL;
  96 }
  97
  98
  99 /*
 100  *      Propagate event for state change to all protocols
 101  */
 102 void ip_vs_protocol_timeout_change(int flags)
 103 {
 104         struct ip_vs_protocol *pp;
 105         int i;
 106
 107         for (i = 0; i < IP_VS_PROTO_TAB_SIZE; i++) {
 108                 for (pp = ip_vs_proto_table[i]; pp; pp = pp->next) {
 109                         if (pp->timeout_change)
 110                                 pp->timeout_change(pp, flags);
 111                 }
 112         }
 113 }
 114
 115
 116 int *
 117 ip_vs_create_timeout_table(int *table, int size)
 118 {
 119         return kmemdup(table, size, GFP_ATOMIC);
 120 }
 121
 122
 123 /*
 124  *      Set timeout value for state specified by name
 125  */
 126 int
 127 ip_vs_set_state_timeout(int *table, int num, char **names, char *name, int to)
 128 {
 129         int i;
 130
 131         if (!table || !name || !to)
 132                 return -EINVAL;
 133
 134         for (i = 0; i < num; i++) {
 135                 if (strcmp(names[i], name))
 136                         continue;
 137                 table[i] = to * HZ;
 138                 return 0;
 139         }
 140         return -ENOENT;
 141 }
 142
 143
 144 const char * ip_vs_state_name(__u16 proto, int state)
 145 {
 146         struct ip_vs_protocol *pp = ip_vs_proto_get(proto);
 147
 148         if (pp == NULL || pp->state_name == NULL)
 149                 return (IPPROTO_IP == proto) ? "NONE" : "ERR!";
 150         return pp->state_name(state);
 151 }
 152
 153
 154 static void
 155 ip_vs_tcpudp_debug_packet_v4(struct ip_vs_protocol *pp,
 156                              const struct sk_buff *skb,
 157                              int offset,
 158                              const char *msg)
 159 {
 160         char buf[128];
 161         struct iphdr _iph, *ih;
 162
 163         ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
 164         if (ih == NULL)
 165                 sprintf(buf, "%s TRUNCATED", pp->name);
 166         else if (ih->frag_off & htons(IP_OFFSET))
 167                 sprintf(buf, "%s %pI4->%pI4 frag",
 168                         pp->name, &ih->saddr, &ih->daddr);
 169         else {
 170                 __be16 _ports[2], *pptr
 171 ;
 172                 pptr = skb_header_pointer(skb, offset + ih->ihl*4,
 173                                           sizeof(_ports), _ports);
 174                 if (pptr == NULL)
 175                         sprintf(buf, "%s TRUNCATED %pI4->%pI4",
 176                                 pp->name, &ih->saddr, &ih->daddr);
 177                 else
 178                         sprintf(buf, "%s %pI4:%u->%pI4:%u",
 179                                 pp->name,
 180                                 &ih->saddr, ntohs(pptr[0]),
 181                                 &ih->daddr, ntohs(pptr[1]));
 182         }
 183
 184         printk(KERN_DEBUG "IPVS: %s: %s\n", msg, buf);
 185 }
 186
 187 #ifdef CONFIG_IP_VS_IPV6
 188 static void
 189 ip_vs_tcpudp_debug_packet_v6(struct ip_vs_protocol *pp,
 190                              const struct sk_buff *skb,
 191                              int offset,
 192                              const char *msg)
 193 {
 194         char buf[192];
 195         struct ipv6hdr _iph, *ih;
 196
 197         ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
 198         if (ih == NULL)
 199                 sprintf(buf, "%s TRUNCATED", pp->name);
 200         else if (ih->nexthdr == IPPROTO_FRAGMENT)
 201                 sprintf(buf, "%s %pI6->%pI6 frag",
 202                         pp->name, &ih->saddr, &ih->daddr);
 203         else {
 204                 __be16 _ports[2], *pptr;
 205
 206                 pptr = skb_header_pointer(skb, offset + sizeof(struct ipv6hdr),
 207                                           sizeof(_ports), _ports);
 208                 if (pptr == NULL)
 209                         sprintf(buf, "%s TRUNCATED %pI6->%pI6",
 210                                 pp->name, &ih->saddr, &ih->daddr);
 211                 else
 212                         sprintf(buf, "%s %pI6:%u->%pI6:%u",
 213                                 pp->name,
 214                                 &ih->saddr, ntohs(pptr[0]),
 215                                 &ih->daddr, ntohs(pptr[1]));
 216         }
 217
 218         printk(KERN_DEBUG "IPVS: %s: %s\n", msg, buf);
 219 }
 220 #endif
 221
 222
 223 void
 224 ip_vs_tcpudp_debug_packet(struct ip_vs_protocol *pp,
 225                           const struct sk_buff *skb,
 226                           int offset,
 227                           const char *msg)
 228 {
 229 #ifdef CONFIG_IP_VS_IPV6
 230         if (skb->protocol == htons(ETH_P_IPV6))
 231                 ip_vs_tcpudp_debug_packet_v6(pp, skb, offset, msg);
 232         else
 233 #endif
 234                 ip_vs_tcpudp_debug_packet_v4(pp, skb, offset, msg);
 235 }
 236
 237
 238 int __init ip_vs_protocol_init(void)
 239 {
 240         char protocols[64];
 241 #define REGISTER_PROTOCOL(p)                    \
 242         do {                                    \
 243                 register_ip_vs_protocol(p);     \
 244                 strcat(protocols, ", ");        \
 245                 strcat(protocols, (p)->name);   \
 246         } while (0)
 247
 248         protocols[0] = '\0';
 249         protocols[2] = '\0';
 250 #ifdef CONFIG_IP_VS_PROTO_TCP
 251         REGISTER_PROTOCOL(&ip_vs_protocol_tcp);
 252 #endif
 253 #ifdef CONFIG_IP_VS_PROTO_UDP
 254         REGISTER_PROTOCOL(&ip_vs_protocol_udp);
 255 #endif
 256 #ifdef CONFIG_IP_VS_PROTO_AH
 257         REGISTER_PROTOCOL(&ip_vs_protocol_ah);
 258 #endif
 259 #ifdef CONFIG_IP_VS_PROTO_ESP
 260         REGISTER_PROTOCOL(&ip_vs_protocol_esp);
 261 #endif
 262         IP_VS_INFO("Registered protocols (%s)\n", &protocols[2]);
 263
 264         return 0;
 265 }
 266
 267
 268 void ip_vs_protocol_cleanup(void)
 269 {
 270         struct ip_vs_protocol *pp;
 271         int i;
 272
 273         /* unregister all the ipvs protocols */
 274         for (i = 0; i < IP_VS_PROTO_TAB_SIZE; i++) {
 275                 while ((pp = ip_vs_proto_table[i]) != NULL)
 276                         unregister_ip_vs_protocol(pp);
 277         }
 278 }