CLEANUP: checks: fix double usage of cur / current_step in tcp-checks

This cleanup is a preliminary requirement to the upcoming fixes for
the bug that affect tcp-check's improper use of lists. It will have
to be backported to 1.5 though it will not easily apply.

There are two variables pointing to the current rule within the loop,
and either one or the other is used depending on the code blocks,
making it much harder to apply checks to fix the list walking bug.
So first get rid of "cur" and only focus on current_step.

diff --git a/src/checks.c b/src/checks.c
index 249df276ce5752b17f4437a4c0d0edd279ef9355..c8f7fdbc4eb520f54a5d4b81585c4e5bd999fb81 100644 (file)
--- a/src/checks.c
+++ b/src/checks.c
@@ -2426,7 +2426,7 @@ static char * tcpcheck_get_step_comment(struct check *check, int stepid)
 static void tcpcheck_main(struct connection *conn)
 {
        char *contentptr, *comment;
-       struct tcpcheck_rule *cur, *next;
+       struct tcpcheck_rule *next;
        int done = 0, ret = 0, step = 0;
        struct check *check = conn->owner;
        struct server *s = check->server;
@@ -2483,15 +2483,11 @@ static void tcpcheck_main(struct connection *conn)
                check->bo->o = 0;
                check->bi->p = check->bi->data;
                check->bi->i = 0;
-               cur = check->current_step = LIST_ELEM(head->n, struct tcpcheck_rule *, list);
+               check->current_step = LIST_ELEM(head->n, struct tcpcheck_rule *, list);
                t->expire = tick_add(now_ms, MS_TO_TICKS(check->inter));
                if (s->proxy->timeout.check)
                        t->expire = tick_add_ifset(now_ms, s->proxy->timeout.check);
        }
-       /* keep on processing step */
-       else {
-               cur = check->current_step;
-       }
 
        /* It's only the rules which will enable send/recv */
        __conn_data_stop_both(conn);
@@ -2501,7 +2497,7 @@ static void tcpcheck_main(struct connection *conn)
                 * or if we're about to send a string that does not fit in the remaining space.
                 */
                if (check->bo->o &&
-                   (&cur->list == head ||
+                   (&check->current_step->list == head ||
                     check->current_step->action != TCPCHK_ACT_SEND ||
                     check->current_step->string_len >= buffer_total_space(check->bo))) {
 
@@ -2516,14 +2512,16 @@ static void tcpcheck_main(struct connection *conn)
                }
 
                /* did we reach the end ? If so, let's check that everything was sent */
-               if (&cur->list == head) {
+               if (&check->current_step->list == head) {
                        if (check->bo->o)
                                goto out_need_io;
                        break;
                }
 
-               /* have 'next' point to the next rule or NULL if we're on the last one */
-               next = (struct tcpcheck_rule *)cur->list.n;
+               /* have 'next' point to the next rule or NULL if we're on the
+                * last one, connect() needs this.
+                */
+               next = (struct tcpcheck_rule *)check->current_step->list.n;
 
                /* bypass all comment rules */
                while (next->action == TCPCHK_ACT_COMMENT)
@@ -2637,13 +2635,11 @@ static void tcpcheck_main(struct connection *conn)
                        }
 
                        /* allow next rule */
-                       cur = (struct tcpcheck_rule *)cur->list.n;
+                       check->current_step = (struct tcpcheck_rule *)check->current_step->list.n;
 
                        /* bypass all comment rules */
-                       while (cur->action == TCPCHK_ACT_COMMENT)
-                               cur = (struct tcpcheck_rule *)cur->list.n;
-
-                       check->current_step = cur;
+                       while (check->current_step->action == TCPCHK_ACT_COMMENT)
+                               check->current_step = (struct tcpcheck_rule *)check->current_step->list.n;
 
                        /* don't do anything until the connection is established */
                        if (!(conn->flags & CO_FL_CONNECTED)) {
@@ -2697,13 +2693,11 @@ static void tcpcheck_main(struct connection *conn)
                        *check->bo->p = '\0'; /* to make gdb output easier to read */
 
                        /* go to next rule and try to send */
-                       cur = (struct tcpcheck_rule *)cur->list.n;
+                       check->current_step = (struct tcpcheck_rule *)check->current_step->list.n;
 
                        /* bypass all comment rules */
-                       while (cur->action == TCPCHK_ACT_COMMENT)
-                               cur = (struct tcpcheck_rule *)cur->list.n;
-
-                       check->current_step = cur;
+                       while (check->current_step->action == TCPCHK_ACT_COMMENT)
+                               check->current_step = (struct tcpcheck_rule *)check->current_step->list.n;
                } /* end 'send' */
                else if (check->current_step->action == TCPCHK_ACT_EXPECT) {
                        if (unlikely(check->result == CHK_RES_FAILED))
@@ -2759,14 +2753,14 @@ static void tcpcheck_main(struct connection *conn)
                                goto out_end_tcpcheck;
                        }
 
-                       if (!done && (cur->string != NULL) && (check->bi->i < cur->string_len) )
+                       if (!done && (check->current_step->string != NULL) && (check->bi->i < check->current_step->string_len) )
                                continue; /* try to read more */
 
                tcpcheck_expect:
-                       if (cur->string != NULL)
-                               ret = my_memmem(contentptr, check->bi->i, cur->string, cur->string_len) != NULL;
-                       else if (cur->expect_regex != NULL)
-                               ret = regex_exec(cur->expect_regex, contentptr);
+                       if (check->current_step->string != NULL)
+                               ret = my_memmem(contentptr, check->bi->i, check->current_step->string, check->current_step->string_len) != NULL;
+                       else if (check->current_step->expect_regex != NULL)
+                               ret = regex_exec(check->current_step->expect_regex, contentptr);
 
                        if (!ret && !done)
                                continue; /* try to read more */
@@ -2775,11 +2769,11 @@ static void tcpcheck_main(struct connection *conn)
                        step = tcpcheck_get_step_id(check);
                        if (ret) {
                                /* matched but we did not want to => ERROR */
-                               if (cur->inverse) {
+                               if (check->current_step->inverse) {
                                        /* we were looking for a string */
-                                       if (cur->string != NULL) {
+                                       if (check->current_step->string != NULL) {
                                                chunk_printf(&trash, "TCPCHK matched unwanted content '%s' at step %d",
-                                                               cur->string, step);
+                                                            check->current_step->string, step);
                                        }
                                        else {
                                        /* we were looking for a regex */
@@ -2794,13 +2788,11 @@ static void tcpcheck_main(struct connection *conn)
                                /* matched and was supposed to => OK, next step */
                                else {
                                        /* allow next rule */
-                                       cur = (struct tcpcheck_rule *)cur->list.n;
+                                       check->current_step = (struct tcpcheck_rule *)check->current_step->list.n;
 
                                        /* bypass all comment rules */
-                                       while (cur->action == TCPCHK_ACT_COMMENT)
-                                               cur = (struct tcpcheck_rule *)cur->list.n;
-
-                                       check->current_step = cur;
+                                       while (check->current_step->action == TCPCHK_ACT_COMMENT)
+                                               check->current_step = (struct tcpcheck_rule *)check->current_step->list.n;
 
                                        if (check->current_step->action == TCPCHK_ACT_EXPECT)
                                                goto tcpcheck_expect;
@@ -2810,15 +2802,13 @@ static void tcpcheck_main(struct connection *conn)
                        else {
                        /* not matched */
                                /* not matched and was not supposed to => OK, next step */
-                               if (cur->inverse) {
+                               if (check->current_step->inverse) {
                                        /* allow next rule */
-                                       cur = (struct tcpcheck_rule *)cur->list.n;
+                                       check->current_step = (struct tcpcheck_rule *)check->current_step->list.n;
 
                                        /* bypass all comment rules */
-                                       while (cur->action == TCPCHK_ACT_COMMENT)
-                                               cur = (struct tcpcheck_rule *)cur->list.n;
-
-                                       check->current_step = cur;
+                                       while (check->current_step->action == TCPCHK_ACT_COMMENT)
+                                               check->current_step = (struct tcpcheck_rule *)check->current_step->list.n;
 
                                        if (check->current_step->action == TCPCHK_ACT_EXPECT)
                                                goto tcpcheck_expect;
@@ -2827,9 +2817,9 @@ static void tcpcheck_main(struct connection *conn)
                                /* not matched but was supposed to => ERROR */
                                else {
                                        /* we were looking for a string */
-                                       if (cur->string != NULL) {
+                                       if (check->current_step->string != NULL) {
                                                chunk_printf(&trash, "TCPCHK did not match content '%s' at step %d",
-                                                               cur->string, step);
+                                                            check->current_step->string, step);
                                        }
                                        else {
                                        /* we were looking for a regex */