]> git.ipfire.org Git - thirdparty/haproxy.git/commitdiff
MEDIUM: peers: Fix a peer stick-tables synchronization issue.
authorFrédéric Lécaille <flecaille@haproxy.com>
Wed, 12 Oct 2016 15:30:30 +0000 (17:30 +0200)
committerWilly Tarreau <w@1wt.eu>
Mon, 17 Oct 2016 17:44:35 +0000 (19:44 +0200)
During the stick-table teaching process which occurs at reloading/restart time,
expiration dates of stick-tables entries were not synchronized between peers.

This patch adds two new stick-table messages to provide such a synchronization feature.

As these new messages are not supported by older haproxy peers protocol versions,
this patch increments peers protol version, from 2.0 to 2.1, to help in detecting/supporting
such older peers protocol implementations so that new versions might still be able
to transparently communicate with a newer one.

[wt: technically speaking it would be nice to have this backported into 1.6
 as some people who reload often are affected by this design limitation, but
 it's not a totally transparent change that may make certain users feel
 reluctant to upgrade older versions. Let's let it cook in 1.7 first and
 decide later]

include/proto/stick_table.h
src/peers.c
src/stick_table.c

index 8c97f733dd0b0736c106147159f4571be495cacc..941e2ff72d1c129911e91481b6dc20e864c96718 100644 (file)
@@ -42,6 +42,10 @@ int stktable_init(struct stktable *t);
 int stktable_parse_type(char **args, int *idx, unsigned long *type, size_t *key_size);
 struct stksess *stktable_get_entry(struct stktable *table, struct stktable_key *key);
 struct stksess *stktable_store(struct stktable *t, struct stksess *ts, int local);
+struct stksess *stktable_store_with_exp(struct stktable *t, struct stksess *ts,
+                                        int local, int expire);
+struct stksess *stktable_touch_with_exp(struct stktable *t, struct stksess *ts,
+                                        int local, int expire);
 struct stksess *stktable_touch(struct stktable *t, struct stksess *ts, int local);
 struct stksess *stktable_lookup(struct stktable *t, struct stksess *ts);
 struct stksess *stktable_lookup_key(struct stktable *t, struct stktable_key *key);
index 6f88c192518e210879eeffb60a3e259041885032..d11792f918dc79abeb43f191bd4ed72fe544eff8 100644 (file)
@@ -23,6 +23,7 @@
 #include <common/compat.h>
 #include <common/config.h>
 #include <common/time.h>
+#include <common/standard.h>
 
 #include <types/global.h>
 #include <types/listener.h>
@@ -80,6 +81,7 @@
 #define        PEER_F_TEACH_COMPLETE           0x00000010 /* All that we know already taught to current peer, used only for a local peer */
 #define        PEER_F_LEARN_ASSIGN             0x00000100 /* Current peer was assigned for a lesson */
 #define        PEER_F_LEARN_NOTUP2DATE         0x00000200 /* Learn from peer finished but peer is not up to date */
+#define        PEER_F_DWNGRD                   0x80000000 /* When this flag is enabled, we must downgrade the supported version announced during peer sessions. */
 
 #define        PEER_TEACH_RESET                ~(PEER_F_TEACH_PROCESS|PEER_F_TEACH_FINISHED) /* PEER_F_TEACH_COMPLETE should never be reset */
 #define        PEER_LEARN_RESET                ~(PEER_F_LEARN_ASSIGN|PEER_F_LEARN_NOTUP2DATE)
@@ -124,6 +126,8 @@ enum {
        PEER_MSG_STKT_DEFINE,
        PEER_MSG_STKT_SWITCH,
        PEER_MSG_STKT_ACK,
+       PEER_MSG_STKT_UPDATE_TIMED,
+       PEER_MSG_STKT_INCUPDATE_TIMED,
 };
 
 /**********************************/
@@ -163,6 +167,9 @@ enum {
 #define        PEER_SESS_SC_ERRPEER            504 /* unknown peer */
 
 #define PEER_SESSION_PROTO_NAME         "HAProxyS"
+#define PEER_MAJOR_VER        2
+#define PEER_MINOR_VER        1
+#define PEER_DWNGRD_MINOR_VER 0
 
 struct peers *peers = NULL;
 static void peer_session_forceshutdown(struct stream * stream);
@@ -230,6 +237,26 @@ uint64_t intdecode(char **str, char *end) {
        return i;
 }
 
+/* Set the stick-table UPDATE message type byte at <msg_type> address,
+ * depending on <use_identifier> and <use_timed> boolean parameters.
+ * Always successful.
+ */
+static inline void peer_set_update_msg_type(char *msg_type, int use_identifier, int use_timed)
+{
+       if (use_timed) {
+               if (use_identifier)
+                       *msg_type = PEER_MSG_STKT_UPDATE_TIMED;
+               else
+                       *msg_type = PEER_MSG_STKT_INCUPDATE_TIMED;
+       }
+       else {
+               if (use_identifier)
+                       *msg_type = PEER_MSG_STKT_UPDATE;
+               else
+                       *msg_type = PEER_MSG_STKT_INCUPDATE;
+       }
+
+}
 /*
  * This prepare the data update message on the stick session <ts>, <st> is the considered
  * stick table.
@@ -237,7 +264,7 @@ uint64_t intdecode(char **str, char *end) {
  * If function returns 0, the caller should consider we were unable to encode this message (TODO:
  * check size)
  */
-static int peer_prepare_updatemsg(struct stksess *ts, struct shared_table *st, char *msg, size_t size, int use_identifier)
+static int peer_prepare_updatemsg(struct stksess *ts, struct shared_table *st, char *msg, size_t size, int use_identifier, int use_timed)
 {
        uint32_t netinteger;
        unsigned short datalen;
@@ -261,6 +288,12 @@ static int peer_prepare_updatemsg(struct stksess *ts, struct shared_table *st, c
                cursor += sizeof(netinteger);
        }
 
+       if (use_timed) {
+               netinteger = htonl(tick_remain(now_ms, ts->expire));
+               memcpy(cursor, &netinteger, sizeof(netinteger));
+               cursor += sizeof(netinteger);
+       }
+
        /* encode the key */
        if (st->table->type == SMP_T_STR) {
                int stlen = strlen((char *)ts->key.key);
@@ -324,11 +357,7 @@ static int peer_prepare_updatemsg(struct stksess *ts, struct shared_table *st, c
 
        /*  prepare message header */
        msg[0] = PEER_MSG_CLASS_STICKTABLE;
-       if (use_identifier)
-               msg[1] = PEER_MSG_STKT_UPDATE;
-       else
-               msg[1] = PEER_MSG_STKT_INCUPDATE;
-
+       peer_set_update_msg_type(&msg[1], use_identifier, use_timed);
        cursor = &msg[2];
        intencode(datalen, &cursor);
 
@@ -477,6 +506,34 @@ static void peer_session_release(struct appctx *appctx)
        }
 }
 
+/* Retrieve the major and minor versions of peers protocol
+ * announced by a remote peer. <str> is a null-terminated
+ * string with the following format: "<maj_ver>.<min_ver>".
+ */
+static int peer_get_version(const char *str,
+                            unsigned int *maj_ver, unsigned int *min_ver)
+{
+       unsigned int majv, minv;
+       const char *pos, *saved;
+       const char *end;
+
+       saved = pos = str;
+       end = str + strlen(str);
+
+       majv = read_uint(&pos, end);
+       if (saved == pos || *pos++ != '.')
+               return -1;
+
+       saved = pos;
+       minv = read_uint(&pos, end);
+       if (saved == pos || pos != end)
+               return -1;
+
+       *maj_ver = majv;
+       *min_ver = minv;
+
+       return 0;
+}
 
 /*
  * IO Handler to handle message exchance with a peer
@@ -488,9 +545,12 @@ static void peer_io_handler(struct appctx *appctx)
        struct peers *curpeers = strm_fe(s)->parent;
        int reql = 0;
        int repl = 0;
+       size_t proto_len = strlen(PEER_SESSION_PROTO_NAME);
+       unsigned int maj_ver, min_ver;
 
        while (1) {
 switchstate:
+               maj_ver = min_ver = (unsigned int)-1;
                switch(appctx->st0) {
                        case PEER_SESS_ST_ACCEPT:
                                appctx->ctx.peers.ptr = NULL;
@@ -515,13 +575,16 @@ switchstate:
 
                                bo_skip(si_oc(si), reql);
 
-                               /* test version */
-                               if (strcmp(PEER_SESSION_PROTO_NAME " 2.0", trash.str) != 0) {
+                               /* test protocol */
+                               if (strncmp(PEER_SESSION_PROTO_NAME " ", trash.str, proto_len + 1) != 0) {
+                                       appctx->st0 = PEER_SESS_ST_EXIT;
+                                       appctx->st1 = PEER_SESS_SC_ERRPROTO;
+                                       goto switchstate;
+                               }
+                               if (peer_get_version(trash.str + proto_len + 1, &maj_ver, &min_ver) == -1 ||
+                                   maj_ver != PEER_MAJOR_VER || min_ver > PEER_MINOR_VER) {
                                        appctx->st0 = PEER_SESS_ST_EXIT;
                                        appctx->st1 = PEER_SESS_SC_ERRVERSION;
-                                       /* test protocol */
-                                       if (strncmp(PEER_SESSION_PROTO_NAME " ", trash.str, strlen(PEER_SESSION_PROTO_NAME)+1) != 0)
-                                               appctx->st1 = PEER_SESS_SC_ERRPROTO;
                                        goto switchstate;
                                }
 
@@ -608,6 +671,14 @@ switchstate:
                                        }
                                        peer_session_forceshutdown(curpeer->stream);
                                }
+                               if (maj_ver != (unsigned int)-1 && min_ver != (unsigned int)-1) {
+                                       if (min_ver == PEER_DWNGRD_MINOR_VER) {
+                                               curpeer->flags |= PEER_F_DWNGRD;
+                                       }
+                                       else {
+                                               curpeer->flags &= ~PEER_F_DWNGRD;
+                                       }
+                               }
                                curpeer->stream = s;
                                curpeer->appctx = appctx;
                                appctx->ctx.peers.ptr = curpeer;
@@ -674,7 +745,9 @@ switchstate:
 
                                /* Send headers */
                                repl = snprintf(trash.str, trash.size,
-                                               PEER_SESSION_PROTO_NAME " 2.0\n%s\n%s %d %d\n",
+                                               PEER_SESSION_PROTO_NAME " %u.%u\n%s\n%s %d %d\n",
+                                               PEER_MAJOR_VER,
+                                               (curpeer->flags & PEER_F_DWNGRD) ? PEER_DWNGRD_MINOR_VER : PEER_MINOR_VER,
                                                curpeer->id,
                                                localpeer,
                                                (int)getpid(),
@@ -762,6 +835,8 @@ switchstate:
 
                                }
                                else {
+                                       if (curpeer->statuscode == PEER_SESS_SC_ERRVERSION)
+                                               curpeer->flags |= PEER_F_DWNGRD;
                                        /* Status code is not success, abort */
                                        appctx->st0 = PEER_SESS_ST_END;
                                        goto switchstate;
@@ -1007,9 +1082,12 @@ switchstate:
 
                                        }
                                        else if (msg_head[1] == PEER_MSG_STKT_UPDATE
-                                                || msg_head[1] == PEER_MSG_STKT_INCUPDATE) {
+                                                || msg_head[1] == PEER_MSG_STKT_INCUPDATE
+                                                || msg_head[1] == PEER_MSG_STKT_UPDATE_TIMED
+                                                || msg_head[1] == PEER_MSG_STKT_INCUPDATE_TIMED) {
                                                struct shared_table *st = curpeer->remote_table;
                                                uint32_t update;
+                                               int expire;
                                                unsigned int data_type;
                                                void *data_ptr;
 
@@ -1017,7 +1095,10 @@ switchstate:
                                                if (!st)
                                                        goto ignore_msg;
 
-                                               if (msg_head[1] == PEER_MSG_STKT_UPDATE) {
+                                               expire = MS_TO_TICKS(st->table->expire);
+
+                                               if (msg_head[1] == PEER_MSG_STKT_UPDATE ||
+                                                   msg_head[1] == PEER_MSG_STKT_UPDATE_TIMED) {
                                                        if (msg_len < sizeof(update)) {
                                                                /* malformed message */
                                                                appctx->st0 = PEER_SESS_ST_ERRPROTO;
@@ -1031,6 +1112,19 @@ switchstate:
                                                        st->last_get++;
                                                }
 
+                                               if (msg_head[1] == PEER_MSG_STKT_UPDATE_TIMED ||
+                                                   msg_head[1] == PEER_MSG_STKT_INCUPDATE_TIMED) {
+                                                       size_t expire_sz = sizeof expire;
+
+                                                       if (msg_cur + expire_sz > msg_end) {
+                                                               appctx->st0 = PEER_SESS_ST_ERRPROTO;
+                                                               goto switchstate;
+                                                       }
+                                                       memcpy(&expire, msg_cur, expire_sz);
+                                                       msg_cur += expire_sz;
+                                                       expire = ntohl(expire);
+                                               }
+
                                                newts = stksess_new(st->table, NULL);
                                                if (!newts)
                                                        goto ignore_msg;
@@ -1086,7 +1180,7 @@ switchstate:
                                                ts = stktable_lookup(st->table, newts);
                                                if (ts) {
                                                        /* the entry already exist, we can free ours */
-                                                       stktable_touch(st->table, ts, 0);
+                                                       stktable_touch_with_exp(st->table, ts, 0, tick_add(now_ms, expire));
                                                        stksess_free(st->table, newts);
                                                        newts = NULL;
                                                }
@@ -1094,7 +1188,7 @@ switchstate:
                                                        struct eb32_node *eb;
 
                                                        /* create new entry */
-                                                       ts = stktable_store(st->table, newts, 0);
+                                                       ts = stktable_store_with_exp(st->table, newts, 0, tick_add(now_ms, expire));
                                                        newts = NULL; /* don't reuse it */
 
                                                        ts->upd.key= (++st->table->update)+(2147483648U);
@@ -1343,7 +1437,7 @@ incomplete:
                                                                        }
 
                                                                        ts = eb32_entry(eb, struct stksess, upd);
-                                                                       msglen = peer_prepare_updatemsg(ts, st, trash.str, trash.size, new_pushed);
+                                                                       msglen = peer_prepare_updatemsg(ts, st, trash.str, trash.size, new_pushed, 0);
                                                                        if (!msglen) {
                                                                                /* internal error: message does not fit in trash */
                                                                                appctx->st0 = PEER_SESS_ST_END;
@@ -1404,6 +1498,7 @@ incomplete:
                                                                while (1) {
                                                                        uint32_t msglen;
                                                                        struct stksess *ts;
+                                                                       int use_timed;
 
                                                                        /* push local updates */
                                                                        if (!eb) {
@@ -1415,7 +1510,8 @@ incomplete:
                                                                        }
 
                                                                        ts = eb32_entry(eb, struct stksess, upd);
-                                                                       msglen = peer_prepare_updatemsg(ts, st, trash.str, trash.size, new_pushed);
+                                                                       use_timed = !(curpeer->flags & PEER_F_DWNGRD);
+                                                                       msglen = peer_prepare_updatemsg(ts, st, trash.str, trash.size, new_pushed, use_timed);
                                                                        if (!msglen) {
                                                                                /* internal error: message does not fit in trash */
                                                                                appctx->st0 = PEER_SESS_ST_END;
@@ -1473,6 +1569,7 @@ incomplete:
                                                                while (1) {
                                                                        uint32_t msglen;
                                                                        struct stksess *ts;
+                                                                       int use_timed;
 
                                                                        /* push local updates */
                                                                        if (!eb || eb->key > st->teaching_origin) {
@@ -1481,7 +1578,8 @@ incomplete:
                                                                        }
 
                                                                        ts = eb32_entry(eb, struct stksess, upd);
-                                                                       msglen = peer_prepare_updatemsg(ts, st, trash.str, trash.size, new_pushed);
+                                                                       use_timed = !(curpeer->flags & PEER_F_DWNGRD);
+                                                                       msglen = peer_prepare_updatemsg(ts, st, trash.str, trash.size, new_pushed, use_timed);
                                                                        if (!msglen) {
                                                                                /* internal error: message does not fit in trash */
                                                                                appctx->st0 = PEER_SESS_ST_END;
index b0aabd4092e4d736d6c24a1f78c76b38fc05b586..b269bc1ea254fd46e1879d445f7c3e5296302f0e 100644 (file)
@@ -244,10 +244,11 @@ struct stksess *stktable_lookup(struct stktable *t, struct stksess *ts)
 /* Update the expiration timer for <ts> but do not touch its expiration node.
  * The table's expiration timer is updated if set.
  */
-struct stksess *stktable_touch(struct stktable *t, struct stksess *ts, int local)
+struct stksess *stktable_touch_with_exp(struct stktable *t, struct stksess *ts,
+                                        int local, int expire)
 {
        struct eb32_node * eb;
-       ts->expire = tick_add(now_ms, MS_TO_TICKS(t->expire));
+       ts->expire = expire;
        if (t->expire) {
                t->exp_task->expire = t->exp_next = tick_first(ts->expire, t->exp_next);
                task_queue(t->exp_task);
@@ -274,6 +275,17 @@ struct stksess *stktable_touch(struct stktable *t, struct stksess *ts, int local
        return ts;
 }
 
+/* Update the expiration timer for <ts> but do not touch its expiration node.
+ * The table's expiration timer is updated if set. The date of expiration coming from
+ * <t> stick-table configuration.
+ */
+struct stksess *stktable_touch(struct stktable *t, struct stksess *ts, int local)
+{
+       int expire = tick_add(now_ms, MS_TO_TICKS(t->expire));
+
+       return stktable_touch_with_exp(t, ts, local, expire);
+}
+
 /* Insert new sticky session <ts> in the table. It is assumed that it does not
  * yet exist (the caller must check this). The table's timeout is updated if it
  * is set. <ts> is returned.
@@ -287,6 +299,20 @@ struct stksess *stktable_store(struct stktable *t, struct stksess *ts, int local
        return ts;
 }
 
+/* Same function as stktable_store(), but with <expire> as supplementary argument
+ * to set the date of expiration of <ts> new sticky session thanks to
+ * stktable_touch_with_exp().
+ */
+struct stksess *stktable_store_with_exp(struct stktable *t, struct stksess *ts,
+                                        int local, int expire)
+{
+       ebmb_insert(&t->keys, &ts->key, t->key_size);
+       stktable_touch_with_exp(t, ts, local, expire);
+       ts->exp.key = ts->expire;
+       eb32_insert(&t->exps, &ts->exp);
+       return ts;
+}
+
 /* Returns a valid or initialized stksess for the specified stktable_key in the
  * specified table, or NULL if the key was NULL, or if no entry was found nor
  * could be created. The entry's expiration is updated.