Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * IPVS An implementation of the IP virtual server support for the |
| 3 | * LINUX operating system. IPVS is now implemented as a module |
| 4 | * over the NetFilter framework. IPVS can be used to build a |
| 5 | * high-performance and highly available server based on a |
| 6 | * cluster of servers. |
| 7 | * |
| 8 | * Version: $Id: ip_vs_sync.c,v 1.13 2003/06/08 09:31:19 wensong Exp $ |
| 9 | * |
| 10 | * Authors: Wensong Zhang <wensong@linuxvirtualserver.org> |
| 11 | * |
| 12 | * ip_vs_sync: sync connection info from master load balancer to backups |
| 13 | * through multicast |
| 14 | * |
| 15 | * Changes: |
| 16 | * Alexandre Cassen : Added master & backup support at a time. |
| 17 | * Alexandre Cassen : Added SyncID support for incoming sync |
| 18 | * messages filtering. |
| 19 | * Justin Ossevoort : Fix endian problem on sync message size. |
| 20 | */ |
| 21 | |
| 22 | #include <linux/module.h> |
| 23 | #include <linux/slab.h> |
Arnaldo Carvalho de Melo | 14c8502 | 2005-12-27 02:43:12 -0200 | [diff] [blame] | 24 | #include <linux/inetdevice.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <linux/net.h> |
| 26 | #include <linux/completion.h> |
| 27 | #include <linux/delay.h> |
| 28 | #include <linux/skbuff.h> |
| 29 | #include <linux/in.h> |
| 30 | #include <linux/igmp.h> /* for ip_mc_join_group */ |
Arnaldo Carvalho de Melo | 14c8502 | 2005-12-27 02:43:12 -0200 | [diff] [blame] | 31 | #include <linux/udp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
| 33 | #include <net/ip.h> |
| 34 | #include <net/sock.h> |
| 35 | #include <asm/uaccess.h> /* for get_fs and set_fs */ |
| 36 | |
| 37 | #include <net/ip_vs.h> |
| 38 | |
| 39 | #define IP_VS_SYNC_GROUP 0xe0000051 /* multicast addr - 224.0.0.81 */ |
| 40 | #define IP_VS_SYNC_PORT 8848 /* multicast port */ |
| 41 | |
| 42 | |
| 43 | /* |
| 44 | * IPVS sync connection entry |
| 45 | */ |
| 46 | struct ip_vs_sync_conn { |
| 47 | __u8 reserved; |
| 48 | |
| 49 | /* Protocol, addresses and port numbers */ |
| 50 | __u8 protocol; /* Which protocol (TCP/UDP) */ |
Al Viro | 014d730 | 2006-09-28 14:29:52 -0700 | [diff] [blame] | 51 | __be16 cport; |
| 52 | __be16 vport; |
| 53 | __be16 dport; |
| 54 | __be32 caddr; /* client address */ |
| 55 | __be32 vaddr; /* virtual address */ |
| 56 | __be32 daddr; /* destination address */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | |
| 58 | /* Flags and state transition */ |
Al Viro | 014d730 | 2006-09-28 14:29:52 -0700 | [diff] [blame] | 59 | __be16 flags; /* status flags */ |
| 60 | __be16 state; /* state info */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | |
| 62 | /* The sequence options start here */ |
| 63 | }; |
| 64 | |
| 65 | struct ip_vs_sync_conn_options { |
| 66 | struct ip_vs_seq in_seq; /* incoming seq. struct */ |
| 67 | struct ip_vs_seq out_seq; /* outgoing seq. struct */ |
| 68 | }; |
| 69 | |
Neil Horman | cc0191a | 2007-06-18 22:33:20 -0700 | [diff] [blame] | 70 | struct ip_vs_sync_thread_data { |
| 71 | struct completion *startup; |
| 72 | int state; |
| 73 | }; |
| 74 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | #define IP_VS_SYNC_CONN_TIMEOUT (3*60*HZ) |
| 76 | #define SIMPLE_CONN_SIZE (sizeof(struct ip_vs_sync_conn)) |
| 77 | #define FULL_CONN_SIZE \ |
| 78 | (sizeof(struct ip_vs_sync_conn) + sizeof(struct ip_vs_sync_conn_options)) |
| 79 | |
| 80 | |
| 81 | /* |
| 82 | The master mulitcasts messages to the backup load balancers in the |
| 83 | following format. |
| 84 | |
| 85 | 0 1 2 3 |
| 86 | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
| 87 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 88 | | Count Conns | SyncID | Size | |
| 89 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 90 | | | |
| 91 | | IPVS Sync Connection (1) | |
| 92 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 93 | | . | |
| 94 | | . | |
| 95 | | . | |
| 96 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 97 | | | |
| 98 | | IPVS Sync Connection (n) | |
| 99 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| 100 | */ |
| 101 | |
| 102 | #define SYNC_MESG_HEADER_LEN 4 |
| 103 | |
| 104 | struct ip_vs_sync_mesg { |
| 105 | __u8 nr_conns; |
| 106 | __u8 syncid; |
| 107 | __u16 size; |
| 108 | |
| 109 | /* ip_vs_sync_conn entries start here */ |
| 110 | }; |
| 111 | |
| 112 | /* the maximum length of sync (sending/receiving) message */ |
| 113 | static int sync_send_mesg_maxlen; |
| 114 | static int sync_recv_mesg_maxlen; |
| 115 | |
| 116 | struct ip_vs_sync_buff { |
| 117 | struct list_head list; |
| 118 | unsigned long firstuse; |
| 119 | |
| 120 | /* pointers for the message data */ |
| 121 | struct ip_vs_sync_mesg *mesg; |
| 122 | unsigned char *head; |
| 123 | unsigned char *end; |
| 124 | }; |
| 125 | |
| 126 | |
| 127 | /* the sync_buff list head and the lock */ |
| 128 | static LIST_HEAD(ip_vs_sync_queue); |
| 129 | static DEFINE_SPINLOCK(ip_vs_sync_lock); |
| 130 | |
| 131 | /* current sync_buff for accepting new conn entries */ |
| 132 | static struct ip_vs_sync_buff *curr_sb = NULL; |
| 133 | static DEFINE_SPINLOCK(curr_sb_lock); |
| 134 | |
| 135 | /* ipvs sync daemon state */ |
| 136 | volatile int ip_vs_sync_state = IP_VS_STATE_NONE; |
| 137 | volatile int ip_vs_master_syncid = 0; |
| 138 | volatile int ip_vs_backup_syncid = 0; |
| 139 | |
| 140 | /* multicast interface name */ |
| 141 | char ip_vs_master_mcast_ifn[IP_VS_IFNAME_MAXLEN]; |
| 142 | char ip_vs_backup_mcast_ifn[IP_VS_IFNAME_MAXLEN]; |
| 143 | |
| 144 | /* multicast addr */ |
| 145 | static struct sockaddr_in mcast_addr; |
| 146 | |
| 147 | |
| 148 | static inline void sb_queue_tail(struct ip_vs_sync_buff *sb) |
| 149 | { |
| 150 | spin_lock(&ip_vs_sync_lock); |
| 151 | list_add_tail(&sb->list, &ip_vs_sync_queue); |
| 152 | spin_unlock(&ip_vs_sync_lock); |
| 153 | } |
| 154 | |
| 155 | static inline struct ip_vs_sync_buff * sb_dequeue(void) |
| 156 | { |
| 157 | struct ip_vs_sync_buff *sb; |
| 158 | |
| 159 | spin_lock_bh(&ip_vs_sync_lock); |
| 160 | if (list_empty(&ip_vs_sync_queue)) { |
| 161 | sb = NULL; |
| 162 | } else { |
| 163 | sb = list_entry(ip_vs_sync_queue.next, |
| 164 | struct ip_vs_sync_buff, |
| 165 | list); |
| 166 | list_del(&sb->list); |
| 167 | } |
| 168 | spin_unlock_bh(&ip_vs_sync_lock); |
| 169 | |
| 170 | return sb; |
| 171 | } |
| 172 | |
| 173 | static inline struct ip_vs_sync_buff * ip_vs_sync_buff_create(void) |
| 174 | { |
| 175 | struct ip_vs_sync_buff *sb; |
| 176 | |
| 177 | if (!(sb=kmalloc(sizeof(struct ip_vs_sync_buff), GFP_ATOMIC))) |
| 178 | return NULL; |
| 179 | |
| 180 | if (!(sb->mesg=kmalloc(sync_send_mesg_maxlen, GFP_ATOMIC))) { |
| 181 | kfree(sb); |
| 182 | return NULL; |
| 183 | } |
| 184 | sb->mesg->nr_conns = 0; |
| 185 | sb->mesg->syncid = ip_vs_master_syncid; |
| 186 | sb->mesg->size = 4; |
| 187 | sb->head = (unsigned char *)sb->mesg + 4; |
| 188 | sb->end = (unsigned char *)sb->mesg + sync_send_mesg_maxlen; |
| 189 | sb->firstuse = jiffies; |
| 190 | return sb; |
| 191 | } |
| 192 | |
| 193 | static inline void ip_vs_sync_buff_release(struct ip_vs_sync_buff *sb) |
| 194 | { |
| 195 | kfree(sb->mesg); |
| 196 | kfree(sb); |
| 197 | } |
| 198 | |
| 199 | /* |
| 200 | * Get the current sync buffer if it has been created for more |
| 201 | * than the specified time or the specified time is zero. |
| 202 | */ |
| 203 | static inline struct ip_vs_sync_buff * |
| 204 | get_curr_sync_buff(unsigned long time) |
| 205 | { |
| 206 | struct ip_vs_sync_buff *sb; |
| 207 | |
| 208 | spin_lock_bh(&curr_sb_lock); |
| 209 | if (curr_sb && (time == 0 || |
| 210 | time_before(jiffies - curr_sb->firstuse, time))) { |
| 211 | sb = curr_sb; |
| 212 | curr_sb = NULL; |
| 213 | } else |
| 214 | sb = NULL; |
| 215 | spin_unlock_bh(&curr_sb_lock); |
| 216 | return sb; |
| 217 | } |
| 218 | |
| 219 | |
| 220 | /* |
| 221 | * Add an ip_vs_conn information into the current sync_buff. |
| 222 | * Called by ip_vs_in. |
| 223 | */ |
| 224 | void ip_vs_sync_conn(struct ip_vs_conn *cp) |
| 225 | { |
| 226 | struct ip_vs_sync_mesg *m; |
| 227 | struct ip_vs_sync_conn *s; |
| 228 | int len; |
| 229 | |
| 230 | spin_lock(&curr_sb_lock); |
| 231 | if (!curr_sb) { |
| 232 | if (!(curr_sb=ip_vs_sync_buff_create())) { |
| 233 | spin_unlock(&curr_sb_lock); |
| 234 | IP_VS_ERR("ip_vs_sync_buff_create failed.\n"); |
| 235 | return; |
| 236 | } |
| 237 | } |
| 238 | |
| 239 | len = (cp->flags & IP_VS_CONN_F_SEQ_MASK) ? FULL_CONN_SIZE : |
| 240 | SIMPLE_CONN_SIZE; |
| 241 | m = curr_sb->mesg; |
| 242 | s = (struct ip_vs_sync_conn *)curr_sb->head; |
| 243 | |
| 244 | /* copy members */ |
| 245 | s->protocol = cp->protocol; |
| 246 | s->cport = cp->cport; |
| 247 | s->vport = cp->vport; |
| 248 | s->dport = cp->dport; |
| 249 | s->caddr = cp->caddr; |
| 250 | s->vaddr = cp->vaddr; |
| 251 | s->daddr = cp->daddr; |
| 252 | s->flags = htons(cp->flags & ~IP_VS_CONN_F_HASHED); |
| 253 | s->state = htons(cp->state); |
| 254 | if (cp->flags & IP_VS_CONN_F_SEQ_MASK) { |
| 255 | struct ip_vs_sync_conn_options *opt = |
| 256 | (struct ip_vs_sync_conn_options *)&s[1]; |
| 257 | memcpy(opt, &cp->in_seq, sizeof(*opt)); |
| 258 | } |
| 259 | |
| 260 | m->nr_conns++; |
| 261 | m->size += len; |
| 262 | curr_sb->head += len; |
| 263 | |
| 264 | /* check if there is a space for next one */ |
| 265 | if (curr_sb->head+FULL_CONN_SIZE > curr_sb->end) { |
| 266 | sb_queue_tail(curr_sb); |
| 267 | curr_sb = NULL; |
| 268 | } |
| 269 | spin_unlock(&curr_sb_lock); |
| 270 | |
| 271 | /* synchronize its controller if it has */ |
| 272 | if (cp->control) |
| 273 | ip_vs_sync_conn(cp->control); |
| 274 | } |
| 275 | |
| 276 | |
| 277 | /* |
| 278 | * Process received multicast message and create the corresponding |
| 279 | * ip_vs_conn entries. |
| 280 | */ |
| 281 | static void ip_vs_process_message(const char *buffer, const size_t buflen) |
| 282 | { |
| 283 | struct ip_vs_sync_mesg *m = (struct ip_vs_sync_mesg *)buffer; |
| 284 | struct ip_vs_sync_conn *s; |
| 285 | struct ip_vs_sync_conn_options *opt; |
| 286 | struct ip_vs_conn *cp; |
| 287 | char *p; |
| 288 | int i; |
| 289 | |
| 290 | /* Convert size back to host byte order */ |
| 291 | m->size = ntohs(m->size); |
| 292 | |
| 293 | if (buflen != m->size) { |
| 294 | IP_VS_ERR("bogus message\n"); |
| 295 | return; |
| 296 | } |
| 297 | |
| 298 | /* SyncID sanity check */ |
| 299 | if (ip_vs_backup_syncid != 0 && m->syncid != ip_vs_backup_syncid) { |
| 300 | IP_VS_DBG(7, "Ignoring incoming msg with syncid = %d\n", |
| 301 | m->syncid); |
| 302 | return; |
| 303 | } |
| 304 | |
| 305 | p = (char *)buffer + sizeof(struct ip_vs_sync_mesg); |
| 306 | for (i=0; i<m->nr_conns; i++) { |
Julian Anastasov | 87375ab | 2005-09-14 21:08:51 -0700 | [diff] [blame] | 307 | unsigned flags; |
| 308 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | s = (struct ip_vs_sync_conn *)p; |
Julian Anastasov | 87375ab | 2005-09-14 21:08:51 -0700 | [diff] [blame] | 310 | flags = ntohs(s->flags); |
| 311 | if (!(flags & IP_VS_CONN_F_TEMPLATE)) |
| 312 | cp = ip_vs_conn_in_get(s->protocol, |
| 313 | s->caddr, s->cport, |
| 314 | s->vaddr, s->vport); |
| 315 | else |
| 316 | cp = ip_vs_ct_in_get(s->protocol, |
| 317 | s->caddr, s->cport, |
| 318 | s->vaddr, s->vport); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 319 | if (!cp) { |
| 320 | cp = ip_vs_conn_new(s->protocol, |
| 321 | s->caddr, s->cport, |
| 322 | s->vaddr, s->vport, |
| 323 | s->daddr, s->dport, |
Julian Anastasov | 87375ab | 2005-09-14 21:08:51 -0700 | [diff] [blame] | 324 | flags, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | if (!cp) { |
| 326 | IP_VS_ERR("ip_vs_conn_new failed\n"); |
| 327 | return; |
| 328 | } |
| 329 | cp->state = ntohs(s->state); |
| 330 | } else if (!cp->dest) { |
| 331 | /* it is an entry created by the synchronization */ |
| 332 | cp->state = ntohs(s->state); |
Julian Anastasov | 87375ab | 2005-09-14 21:08:51 -0700 | [diff] [blame] | 333 | cp->flags = flags | IP_VS_CONN_F_HASHED; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 334 | } /* Note that we don't touch its state and flags |
| 335 | if it is a normal entry. */ |
| 336 | |
Julian Anastasov | 87375ab | 2005-09-14 21:08:51 -0700 | [diff] [blame] | 337 | if (flags & IP_VS_CONN_F_SEQ_MASK) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | opt = (struct ip_vs_sync_conn_options *)&s[1]; |
| 339 | memcpy(&cp->in_seq, opt, sizeof(*opt)); |
| 340 | p += FULL_CONN_SIZE; |
| 341 | } else |
| 342 | p += SIMPLE_CONN_SIZE; |
| 343 | |
| 344 | atomic_set(&cp->in_pkts, sysctl_ip_vs_sync_threshold[0]); |
| 345 | cp->timeout = IP_VS_SYNC_CONN_TIMEOUT; |
| 346 | ip_vs_conn_put(cp); |
| 347 | |
| 348 | if (p > buffer+buflen) { |
| 349 | IP_VS_ERR("bogus message\n"); |
| 350 | return; |
| 351 | } |
| 352 | } |
| 353 | } |
| 354 | |
| 355 | |
| 356 | /* |
| 357 | * Setup loopback of outgoing multicasts on a sending socket |
| 358 | */ |
| 359 | static void set_mcast_loop(struct sock *sk, u_char loop) |
| 360 | { |
| 361 | struct inet_sock *inet = inet_sk(sk); |
| 362 | |
| 363 | /* setsockopt(sock, SOL_IP, IP_MULTICAST_LOOP, &loop, sizeof(loop)); */ |
| 364 | lock_sock(sk); |
| 365 | inet->mc_loop = loop ? 1 : 0; |
| 366 | release_sock(sk); |
| 367 | } |
| 368 | |
| 369 | /* |
| 370 | * Specify TTL for outgoing multicasts on a sending socket |
| 371 | */ |
| 372 | static void set_mcast_ttl(struct sock *sk, u_char ttl) |
| 373 | { |
| 374 | struct inet_sock *inet = inet_sk(sk); |
| 375 | |
| 376 | /* setsockopt(sock, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); */ |
| 377 | lock_sock(sk); |
| 378 | inet->mc_ttl = ttl; |
| 379 | release_sock(sk); |
| 380 | } |
| 381 | |
| 382 | /* |
| 383 | * Specifiy default interface for outgoing multicasts |
| 384 | */ |
| 385 | static int set_mcast_if(struct sock *sk, char *ifname) |
| 386 | { |
| 387 | struct net_device *dev; |
| 388 | struct inet_sock *inet = inet_sk(sk); |
| 389 | |
| 390 | if ((dev = __dev_get_by_name(ifname)) == NULL) |
| 391 | return -ENODEV; |
| 392 | |
| 393 | if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if) |
| 394 | return -EINVAL; |
| 395 | |
| 396 | lock_sock(sk); |
| 397 | inet->mc_index = dev->ifindex; |
| 398 | /* inet->mc_addr = 0; */ |
| 399 | release_sock(sk); |
| 400 | |
| 401 | return 0; |
| 402 | } |
| 403 | |
| 404 | |
| 405 | /* |
| 406 | * Set the maximum length of sync message according to the |
| 407 | * specified interface's MTU. |
| 408 | */ |
| 409 | static int set_sync_mesg_maxlen(int sync_state) |
| 410 | { |
| 411 | struct net_device *dev; |
| 412 | int num; |
| 413 | |
| 414 | if (sync_state == IP_VS_STATE_MASTER) { |
| 415 | if ((dev = __dev_get_by_name(ip_vs_master_mcast_ifn)) == NULL) |
| 416 | return -ENODEV; |
| 417 | |
| 418 | num = (dev->mtu - sizeof(struct iphdr) - |
| 419 | sizeof(struct udphdr) - |
| 420 | SYNC_MESG_HEADER_LEN - 20) / SIMPLE_CONN_SIZE; |
| 421 | sync_send_mesg_maxlen = |
| 422 | SYNC_MESG_HEADER_LEN + SIMPLE_CONN_SIZE * num; |
| 423 | IP_VS_DBG(7, "setting the maximum length of sync sending " |
| 424 | "message %d.\n", sync_send_mesg_maxlen); |
| 425 | } else if (sync_state == IP_VS_STATE_BACKUP) { |
| 426 | if ((dev = __dev_get_by_name(ip_vs_backup_mcast_ifn)) == NULL) |
| 427 | return -ENODEV; |
| 428 | |
| 429 | sync_recv_mesg_maxlen = dev->mtu - |
| 430 | sizeof(struct iphdr) - sizeof(struct udphdr); |
| 431 | IP_VS_DBG(7, "setting the maximum length of sync receiving " |
| 432 | "message %d.\n", sync_recv_mesg_maxlen); |
| 433 | } |
| 434 | |
| 435 | return 0; |
| 436 | } |
| 437 | |
| 438 | |
| 439 | /* |
| 440 | * Join a multicast group. |
| 441 | * the group is specified by a class D multicast address 224.0.0.0/8 |
| 442 | * in the in_addr structure passed in as a parameter. |
| 443 | */ |
| 444 | static int |
| 445 | join_mcast_group(struct sock *sk, struct in_addr *addr, char *ifname) |
| 446 | { |
| 447 | struct ip_mreqn mreq; |
| 448 | struct net_device *dev; |
| 449 | int ret; |
| 450 | |
| 451 | memset(&mreq, 0, sizeof(mreq)); |
| 452 | memcpy(&mreq.imr_multiaddr, addr, sizeof(struct in_addr)); |
| 453 | |
| 454 | if ((dev = __dev_get_by_name(ifname)) == NULL) |
| 455 | return -ENODEV; |
| 456 | if (sk->sk_bound_dev_if && dev->ifindex != sk->sk_bound_dev_if) |
| 457 | return -EINVAL; |
| 458 | |
| 459 | mreq.imr_ifindex = dev->ifindex; |
| 460 | |
| 461 | lock_sock(sk); |
| 462 | ret = ip_mc_join_group(sk, &mreq); |
| 463 | release_sock(sk); |
| 464 | |
| 465 | return ret; |
| 466 | } |
| 467 | |
| 468 | |
| 469 | static int bind_mcastif_addr(struct socket *sock, char *ifname) |
| 470 | { |
| 471 | struct net_device *dev; |
Al Viro | a61ced5 | 2006-09-26 21:27:54 -0700 | [diff] [blame] | 472 | __be32 addr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | struct sockaddr_in sin; |
| 474 | |
| 475 | if ((dev = __dev_get_by_name(ifname)) == NULL) |
| 476 | return -ENODEV; |
| 477 | |
| 478 | addr = inet_select_addr(dev, 0, RT_SCOPE_UNIVERSE); |
| 479 | if (!addr) |
| 480 | IP_VS_ERR("You probably need to specify IP address on " |
| 481 | "multicast interface.\n"); |
| 482 | |
| 483 | IP_VS_DBG(7, "binding socket with (%s) %u.%u.%u.%u\n", |
| 484 | ifname, NIPQUAD(addr)); |
| 485 | |
| 486 | /* Now bind the socket with the address of multicast interface */ |
| 487 | sin.sin_family = AF_INET; |
| 488 | sin.sin_addr.s_addr = addr; |
| 489 | sin.sin_port = 0; |
| 490 | |
| 491 | return sock->ops->bind(sock, (struct sockaddr*)&sin, sizeof(sin)); |
| 492 | } |
| 493 | |
| 494 | /* |
| 495 | * Set up sending multicast socket over UDP |
| 496 | */ |
| 497 | static struct socket * make_send_sock(void) |
| 498 | { |
| 499 | struct socket *sock; |
| 500 | |
| 501 | /* First create a socket */ |
| 502 | if (sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) < 0) { |
| 503 | IP_VS_ERR("Error during creation of socket; terminating\n"); |
| 504 | return NULL; |
| 505 | } |
| 506 | |
| 507 | if (set_mcast_if(sock->sk, ip_vs_master_mcast_ifn) < 0) { |
| 508 | IP_VS_ERR("Error setting outbound mcast interface\n"); |
| 509 | goto error; |
| 510 | } |
| 511 | |
| 512 | set_mcast_loop(sock->sk, 0); |
| 513 | set_mcast_ttl(sock->sk, 1); |
| 514 | |
| 515 | if (bind_mcastif_addr(sock, ip_vs_master_mcast_ifn) < 0) { |
| 516 | IP_VS_ERR("Error binding address of the mcast interface\n"); |
| 517 | goto error; |
| 518 | } |
| 519 | |
| 520 | if (sock->ops->connect(sock, |
| 521 | (struct sockaddr*)&mcast_addr, |
| 522 | sizeof(struct sockaddr), 0) < 0) { |
| 523 | IP_VS_ERR("Error connecting to the multicast addr\n"); |
| 524 | goto error; |
| 525 | } |
| 526 | |
| 527 | return sock; |
| 528 | |
| 529 | error: |
| 530 | sock_release(sock); |
| 531 | return NULL; |
| 532 | } |
| 533 | |
| 534 | |
| 535 | /* |
| 536 | * Set up receiving multicast socket over UDP |
| 537 | */ |
| 538 | static struct socket * make_receive_sock(void) |
| 539 | { |
| 540 | struct socket *sock; |
| 541 | |
| 542 | /* First create a socket */ |
| 543 | if (sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) < 0) { |
| 544 | IP_VS_ERR("Error during creation of socket; terminating\n"); |
| 545 | return NULL; |
| 546 | } |
| 547 | |
| 548 | /* it is equivalent to the REUSEADDR option in user-space */ |
| 549 | sock->sk->sk_reuse = 1; |
| 550 | |
| 551 | if (sock->ops->bind(sock, |
| 552 | (struct sockaddr*)&mcast_addr, |
| 553 | sizeof(struct sockaddr)) < 0) { |
| 554 | IP_VS_ERR("Error binding to the multicast addr\n"); |
| 555 | goto error; |
| 556 | } |
| 557 | |
| 558 | /* join the multicast group */ |
| 559 | if (join_mcast_group(sock->sk, |
| 560 | (struct in_addr*)&mcast_addr.sin_addr, |
| 561 | ip_vs_backup_mcast_ifn) < 0) { |
| 562 | IP_VS_ERR("Error joining to the multicast group\n"); |
| 563 | goto error; |
| 564 | } |
| 565 | |
| 566 | return sock; |
| 567 | |
| 568 | error: |
| 569 | sock_release(sock); |
| 570 | return NULL; |
| 571 | } |
| 572 | |
| 573 | |
| 574 | static int |
| 575 | ip_vs_send_async(struct socket *sock, const char *buffer, const size_t length) |
| 576 | { |
| 577 | struct msghdr msg = {.msg_flags = MSG_DONTWAIT|MSG_NOSIGNAL}; |
| 578 | struct kvec iov; |
| 579 | int len; |
| 580 | |
| 581 | EnterFunction(7); |
| 582 | iov.iov_base = (void *)buffer; |
| 583 | iov.iov_len = length; |
| 584 | |
| 585 | len = kernel_sendmsg(sock, &msg, &iov, 1, (size_t)(length)); |
| 586 | |
| 587 | LeaveFunction(7); |
| 588 | return len; |
| 589 | } |
| 590 | |
| 591 | static void |
| 592 | ip_vs_send_sync_msg(struct socket *sock, struct ip_vs_sync_mesg *msg) |
| 593 | { |
| 594 | int msize; |
| 595 | |
| 596 | msize = msg->size; |
| 597 | |
| 598 | /* Put size in network byte order */ |
| 599 | msg->size = htons(msg->size); |
| 600 | |
| 601 | if (ip_vs_send_async(sock, (char *)msg, msize) != msize) |
| 602 | IP_VS_ERR("ip_vs_send_async error\n"); |
| 603 | } |
| 604 | |
| 605 | static int |
| 606 | ip_vs_receive(struct socket *sock, char *buffer, const size_t buflen) |
| 607 | { |
| 608 | struct msghdr msg = {NULL,}; |
| 609 | struct kvec iov; |
| 610 | int len; |
| 611 | |
| 612 | EnterFunction(7); |
| 613 | |
| 614 | /* Receive a packet */ |
| 615 | iov.iov_base = buffer; |
| 616 | iov.iov_len = (size_t)buflen; |
| 617 | |
| 618 | len = kernel_recvmsg(sock, &msg, &iov, 1, buflen, 0); |
| 619 | |
| 620 | if (len < 0) |
| 621 | return -1; |
| 622 | |
| 623 | LeaveFunction(7); |
| 624 | return len; |
| 625 | } |
| 626 | |
| 627 | |
| 628 | static DECLARE_WAIT_QUEUE_HEAD(sync_wait); |
| 629 | static pid_t sync_master_pid = 0; |
| 630 | static pid_t sync_backup_pid = 0; |
| 631 | |
| 632 | static DECLARE_WAIT_QUEUE_HEAD(stop_sync_wait); |
| 633 | static int stop_master_sync = 0; |
| 634 | static int stop_backup_sync = 0; |
| 635 | |
| 636 | static void sync_master_loop(void) |
| 637 | { |
| 638 | struct socket *sock; |
| 639 | struct ip_vs_sync_buff *sb; |
| 640 | |
| 641 | /* create the sending multicast socket */ |
| 642 | sock = make_send_sock(); |
| 643 | if (!sock) |
| 644 | return; |
| 645 | |
| 646 | IP_VS_INFO("sync thread started: state = MASTER, mcast_ifn = %s, " |
| 647 | "syncid = %d\n", |
| 648 | ip_vs_master_mcast_ifn, ip_vs_master_syncid); |
| 649 | |
| 650 | for (;;) { |
| 651 | while ((sb=sb_dequeue())) { |
| 652 | ip_vs_send_sync_msg(sock, sb->mesg); |
| 653 | ip_vs_sync_buff_release(sb); |
| 654 | } |
| 655 | |
| 656 | /* check if entries stay in curr_sb for 2 seconds */ |
| 657 | if ((sb = get_curr_sync_buff(2*HZ))) { |
| 658 | ip_vs_send_sync_msg(sock, sb->mesg); |
| 659 | ip_vs_sync_buff_release(sb); |
| 660 | } |
| 661 | |
| 662 | if (stop_master_sync) |
| 663 | break; |
| 664 | |
Simon Horman | 89eaeb0 | 2006-12-10 22:35:24 -0800 | [diff] [blame] | 665 | msleep_interruptible(1000); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 666 | } |
| 667 | |
| 668 | /* clean up the sync_buff queue */ |
| 669 | while ((sb=sb_dequeue())) { |
| 670 | ip_vs_sync_buff_release(sb); |
| 671 | } |
| 672 | |
| 673 | /* clean up the current sync_buff */ |
| 674 | if ((sb = get_curr_sync_buff(0))) { |
| 675 | ip_vs_sync_buff_release(sb); |
| 676 | } |
| 677 | |
| 678 | /* release the sending multicast socket */ |
| 679 | sock_release(sock); |
| 680 | } |
| 681 | |
| 682 | |
| 683 | static void sync_backup_loop(void) |
| 684 | { |
| 685 | struct socket *sock; |
| 686 | char *buf; |
| 687 | int len; |
| 688 | |
| 689 | if (!(buf = kmalloc(sync_recv_mesg_maxlen, GFP_ATOMIC))) { |
| 690 | IP_VS_ERR("sync_backup_loop: kmalloc error\n"); |
| 691 | return; |
| 692 | } |
| 693 | |
| 694 | /* create the receiving multicast socket */ |
| 695 | sock = make_receive_sock(); |
| 696 | if (!sock) |
| 697 | goto out; |
| 698 | |
| 699 | IP_VS_INFO("sync thread started: state = BACKUP, mcast_ifn = %s, " |
| 700 | "syncid = %d\n", |
| 701 | ip_vs_backup_mcast_ifn, ip_vs_backup_syncid); |
| 702 | |
| 703 | for (;;) { |
| 704 | /* do you have data now? */ |
| 705 | while (!skb_queue_empty(&(sock->sk->sk_receive_queue))) { |
| 706 | if ((len = |
| 707 | ip_vs_receive(sock, buf, |
| 708 | sync_recv_mesg_maxlen)) <= 0) { |
| 709 | IP_VS_ERR("receiving message error\n"); |
| 710 | break; |
| 711 | } |
| 712 | /* disable bottom half, because it accessed the data |
| 713 | shared by softirq while getting/creating conns */ |
| 714 | local_bh_disable(); |
| 715 | ip_vs_process_message(buf, len); |
| 716 | local_bh_enable(); |
| 717 | } |
| 718 | |
| 719 | if (stop_backup_sync) |
| 720 | break; |
| 721 | |
Simon Horman | 89eaeb0 | 2006-12-10 22:35:24 -0800 | [diff] [blame] | 722 | msleep_interruptible(1000); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 723 | } |
| 724 | |
| 725 | /* release the sending multicast socket */ |
| 726 | sock_release(sock); |
| 727 | |
| 728 | out: |
| 729 | kfree(buf); |
| 730 | } |
| 731 | |
| 732 | |
| 733 | static void set_sync_pid(int sync_state, pid_t sync_pid) |
| 734 | { |
| 735 | if (sync_state == IP_VS_STATE_MASTER) |
| 736 | sync_master_pid = sync_pid; |
| 737 | else if (sync_state == IP_VS_STATE_BACKUP) |
| 738 | sync_backup_pid = sync_pid; |
| 739 | } |
| 740 | |
| 741 | static void set_stop_sync(int sync_state, int set) |
| 742 | { |
| 743 | if (sync_state == IP_VS_STATE_MASTER) |
| 744 | stop_master_sync = set; |
| 745 | else if (sync_state == IP_VS_STATE_BACKUP) |
| 746 | stop_backup_sync = set; |
| 747 | else { |
| 748 | stop_master_sync = set; |
| 749 | stop_backup_sync = set; |
| 750 | } |
| 751 | } |
| 752 | |
| 753 | static int sync_thread(void *startup) |
| 754 | { |
| 755 | DECLARE_WAITQUEUE(wait, current); |
| 756 | mm_segment_t oldmm; |
| 757 | int state; |
| 758 | const char *name; |
Neil Horman | cc0191a | 2007-06-18 22:33:20 -0700 | [diff] [blame] | 759 | struct ip_vs_sync_thread_data *tinfo = startup; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 760 | |
| 761 | /* increase the module use count */ |
| 762 | ip_vs_use_count_inc(); |
| 763 | |
| 764 | if (ip_vs_sync_state & IP_VS_STATE_MASTER && !sync_master_pid) { |
| 765 | state = IP_VS_STATE_MASTER; |
| 766 | name = "ipvs_syncmaster"; |
| 767 | } else if (ip_vs_sync_state & IP_VS_STATE_BACKUP && !sync_backup_pid) { |
| 768 | state = IP_VS_STATE_BACKUP; |
| 769 | name = "ipvs_syncbackup"; |
| 770 | } else { |
| 771 | IP_VS_BUG(); |
| 772 | ip_vs_use_count_dec(); |
| 773 | return -EINVAL; |
| 774 | } |
| 775 | |
| 776 | daemonize(name); |
| 777 | |
| 778 | oldmm = get_fs(); |
| 779 | set_fs(KERNEL_DS); |
| 780 | |
| 781 | /* Block all signals */ |
| 782 | spin_lock_irq(¤t->sighand->siglock); |
| 783 | siginitsetinv(¤t->blocked, 0); |
| 784 | recalc_sigpending(); |
| 785 | spin_unlock_irq(¤t->sighand->siglock); |
| 786 | |
| 787 | /* set the maximum length of sync message */ |
| 788 | set_sync_mesg_maxlen(state); |
| 789 | |
| 790 | /* set up multicast address */ |
| 791 | mcast_addr.sin_family = AF_INET; |
| 792 | mcast_addr.sin_port = htons(IP_VS_SYNC_PORT); |
| 793 | mcast_addr.sin_addr.s_addr = htonl(IP_VS_SYNC_GROUP); |
| 794 | |
| 795 | add_wait_queue(&sync_wait, &wait); |
| 796 | |
| 797 | set_sync_pid(state, current->pid); |
Neil Horman | cc0191a | 2007-06-18 22:33:20 -0700 | [diff] [blame] | 798 | complete(tinfo->startup); |
| 799 | |
| 800 | /* |
| 801 | * once we call the completion queue above, we should |
| 802 | * null out that reference, since its allocated on the |
| 803 | * stack of the creating kernel thread |
| 804 | */ |
| 805 | tinfo->startup = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 806 | |
| 807 | /* processing master/backup loop here */ |
| 808 | if (state == IP_VS_STATE_MASTER) |
| 809 | sync_master_loop(); |
| 810 | else if (state == IP_VS_STATE_BACKUP) |
| 811 | sync_backup_loop(); |
| 812 | else IP_VS_BUG(); |
| 813 | |
| 814 | remove_wait_queue(&sync_wait, &wait); |
| 815 | |
| 816 | /* thread exits */ |
Neil Horman | cc0191a | 2007-06-18 22:33:20 -0700 | [diff] [blame] | 817 | |
| 818 | /* |
| 819 | * If we weren't explicitly stopped, then we |
| 820 | * exited in error, and should undo our state |
| 821 | */ |
| 822 | if ((!stop_master_sync) && (!stop_backup_sync)) |
| 823 | ip_vs_sync_state -= tinfo->state; |
| 824 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 825 | set_sync_pid(state, 0); |
| 826 | IP_VS_INFO("sync thread stopped!\n"); |
| 827 | |
| 828 | set_fs(oldmm); |
| 829 | |
| 830 | /* decrease the module use count */ |
| 831 | ip_vs_use_count_dec(); |
| 832 | |
| 833 | set_stop_sync(state, 0); |
| 834 | wake_up(&stop_sync_wait); |
| 835 | |
Neil Horman | cc0191a | 2007-06-18 22:33:20 -0700 | [diff] [blame] | 836 | /* |
| 837 | * we need to free the structure that was allocated |
| 838 | * for us in start_sync_thread |
| 839 | */ |
| 840 | kfree(tinfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 841 | return 0; |
| 842 | } |
| 843 | |
| 844 | |
| 845 | static int fork_sync_thread(void *startup) |
| 846 | { |
| 847 | pid_t pid; |
| 848 | |
| 849 | /* fork the sync thread here, then the parent process of the |
| 850 | sync thread is the init process after this thread exits. */ |
| 851 | repeat: |
| 852 | if ((pid = kernel_thread(sync_thread, startup, 0)) < 0) { |
| 853 | IP_VS_ERR("could not create sync_thread due to %d... " |
| 854 | "retrying.\n", pid); |
Simon Horman | 89eaeb0 | 2006-12-10 22:35:24 -0800 | [diff] [blame] | 855 | msleep_interruptible(1000); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 856 | goto repeat; |
| 857 | } |
| 858 | |
| 859 | return 0; |
| 860 | } |
| 861 | |
| 862 | |
| 863 | int start_sync_thread(int state, char *mcast_ifn, __u8 syncid) |
| 864 | { |
Peter Zijlstra | 6e9a473 | 2006-09-30 23:28:10 -0700 | [diff] [blame] | 865 | DECLARE_COMPLETION_ONSTACK(startup); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 866 | pid_t pid; |
Neil Horman | cc0191a | 2007-06-18 22:33:20 -0700 | [diff] [blame] | 867 | struct ip_vs_sync_thread_data *tinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 868 | |
| 869 | if ((state == IP_VS_STATE_MASTER && sync_master_pid) || |
| 870 | (state == IP_VS_STATE_BACKUP && sync_backup_pid)) |
| 871 | return -EEXIST; |
| 872 | |
Neil Horman | cc0191a | 2007-06-18 22:33:20 -0700 | [diff] [blame] | 873 | /* |
| 874 | * Note that tinfo will be freed in sync_thread on exit |
| 875 | */ |
| 876 | tinfo = kmalloc(sizeof(struct ip_vs_sync_thread_data), GFP_KERNEL); |
| 877 | if (!tinfo) |
| 878 | return -ENOMEM; |
| 879 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 880 | IP_VS_DBG(7, "%s: pid %d\n", __FUNCTION__, current->pid); |
| 881 | IP_VS_DBG(7, "Each ip_vs_sync_conn entry need %Zd bytes\n", |
| 882 | sizeof(struct ip_vs_sync_conn)); |
| 883 | |
| 884 | ip_vs_sync_state |= state; |
| 885 | if (state == IP_VS_STATE_MASTER) { |
Simon Horman | 37004af | 2006-12-10 22:36:18 -0800 | [diff] [blame] | 886 | strlcpy(ip_vs_master_mcast_ifn, mcast_ifn, |
| 887 | sizeof(ip_vs_master_mcast_ifn)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 888 | ip_vs_master_syncid = syncid; |
| 889 | } else { |
Simon Horman | 37004af | 2006-12-10 22:36:18 -0800 | [diff] [blame] | 890 | strlcpy(ip_vs_backup_mcast_ifn, mcast_ifn, |
| 891 | sizeof(ip_vs_backup_mcast_ifn)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 892 | ip_vs_backup_syncid = syncid; |
| 893 | } |
| 894 | |
Neil Horman | cc0191a | 2007-06-18 22:33:20 -0700 | [diff] [blame] | 895 | tinfo->state = state; |
| 896 | tinfo->startup = &startup; |
| 897 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 898 | repeat: |
Neil Horman | cc0191a | 2007-06-18 22:33:20 -0700 | [diff] [blame] | 899 | if ((pid = kernel_thread(fork_sync_thread, tinfo, 0)) < 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 900 | IP_VS_ERR("could not create fork_sync_thread due to %d... " |
| 901 | "retrying.\n", pid); |
Simon Horman | 89eaeb0 | 2006-12-10 22:35:24 -0800 | [diff] [blame] | 902 | msleep_interruptible(1000); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | goto repeat; |
| 904 | } |
| 905 | |
| 906 | wait_for_completion(&startup); |
| 907 | |
| 908 | return 0; |
| 909 | } |
| 910 | |
| 911 | |
| 912 | int stop_sync_thread(int state) |
| 913 | { |
| 914 | DECLARE_WAITQUEUE(wait, current); |
| 915 | |
| 916 | if ((state == IP_VS_STATE_MASTER && !sync_master_pid) || |
| 917 | (state == IP_VS_STATE_BACKUP && !sync_backup_pid)) |
| 918 | return -ESRCH; |
| 919 | |
| 920 | IP_VS_DBG(7, "%s: pid %d\n", __FUNCTION__, current->pid); |
| 921 | IP_VS_INFO("stopping sync thread %d ...\n", |
Simon Horman | 37004af | 2006-12-10 22:36:18 -0800 | [diff] [blame] | 922 | (state == IP_VS_STATE_MASTER) ? |
| 923 | sync_master_pid : sync_backup_pid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 924 | |
| 925 | __set_current_state(TASK_UNINTERRUPTIBLE); |
| 926 | add_wait_queue(&stop_sync_wait, &wait); |
| 927 | set_stop_sync(state, 1); |
| 928 | ip_vs_sync_state -= state; |
| 929 | wake_up(&sync_wait); |
| 930 | schedule(); |
| 931 | __set_current_state(TASK_RUNNING); |
| 932 | remove_wait_queue(&stop_sync_wait, &wait); |
| 933 | |
| 934 | /* Note: no need to reap the sync thread, because its parent |
| 935 | process is the init process */ |
| 936 | |
| 937 | if ((state == IP_VS_STATE_MASTER && stop_master_sync) || |
| 938 | (state == IP_VS_STATE_BACKUP && stop_backup_sync)) |
| 939 | IP_VS_BUG(); |
| 940 | |
| 941 | return 0; |
| 942 | } |