[BUG] check: http-check expect + regex would crash in defaults section

Manoj Kumar reported a case where haproxy would crash upon start-up. The
cause was an "http-check expect" statement declared in the defaults section,
which caused a NULL regex to be used during the check. This statement is not
allowed in defaults sections precisely because this requires saving a copy
of the regex in the default proxy. But the check was not made to prevent it
from being declared there, hence the issue.

Instead of adding code to detect its abnormal use, we decided to implement
it. It was not that much complex because the expect_str part was not used
with regexes, so it could hold the string form of the regex in order to
compile it again for every backend (there's no way to clone regexes).

This patch has been tested and works. So it's both a bugfix and a minor
feature enhancement.

It should be backported to 1.4 though it's not critical since the config
was not supposed to be supported.

diff --git a/doc/configuration.txt b/doc/configuration.txt
index afffc63ebe933d951f577638ace342623434bad1..291cb013fc9278138004f83ab2c75ab2befc2fcb 100644 (file)
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -2330,7 +2330,7 @@ http-check disable-on-404
 http-check expect [!] <match> <pattern>
   Make HTTP health checks consider reponse contents or specific status codes
   May be used in sections :   defaults | frontend | listen | backend
-                                  no   |    no    |   yes  |   yes
+                                 yes   |    no    |   yes  |   yes
   Arguments :
     <match>   is a keyword indicating how to look for a specific pattern in the
               response. The keyword may be one of "status", "rstatus",

diff --git a/include/types/proxy.h b/include/types/proxy.h
index e4fcc7750d2abc1b3df7e66fe5b9e62192f362a2..da64bb1d7ed1e883f0a810576b1304bed2407759 100644 (file)
--- a/include/types/proxy.h
+++ b/include/types/proxy.h
@@ -316,7 +316,7 @@ struct proxy {
        int grace;                              /* grace time after stop request */
        char *check_req;                        /* HTTP or SSL request to use for PR_O_HTTP_CHK|PR_O_SSL3_CHK */
        int check_len;                          /* Length of the HTTP or SSL3 request */
-       char *expect_str;                       /* http-check expected content */
+       char *expect_str;                       /* http-check expected content : string or text version of the regex */
        regex_t *expect_regex;                  /* http-check expected content */
        struct chunk errmsg[HTTP_ERR_SIZE];     /* default or customized error messages for known errors */
        int uuid;                               /* universally unique proxy ID, used for SNMP */

diff --git a/src/cfgparse.c b/src/cfgparse.c
index 8c61f3d5353f993b03b8f7aca76fd8e93b123adb..f6a0ef2fe6ff002a2e3e2b822514b88cb0a3089e 100644 (file)
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -1425,6 +1425,15 @@ int cfg_parse_listen(const char *file, int linenum, char **args, int kwm)
                        }
                        curproxy->check_len = defproxy.check_len;
 
+                       if (defproxy.expect_str) {
+                               curproxy->expect_str = strdup(defproxy.expect_str);
+                               if (defproxy.expect_regex) {
+                                       /* note: this regex is known to be valid */
+                                       curproxy->expect_regex = calloc(1, sizeof(regex_t));
+                                       regcomp(curproxy->expect_regex, defproxy.expect_str, REG_EXTENDED);
+                               }
+                       }
+
                        if (defproxy.cookie_name)
                                curproxy->cookie_name = strdup(defproxy.cookie_name);
                        curproxy->cookie_len = defproxy.cookie_len;
@@ -1522,6 +1531,8 @@ int cfg_parse_listen(const char *file, int linenum, char **args, int kwm)
                defproxy.fwdfor_hdr_len = 0;
                free(defproxy.orgto_hdr_name);
                defproxy.orgto_hdr_len = 0;
+               free(defproxy.expect_str);
+               if (defproxy.expect_regex) regfree(defproxy.expect_regex);
 
                for (rc = 0; rc < HTTP_ERR_SIZE; rc++)
                        chunk_destroy(&defproxy.errmsg[rc]);
@@ -3635,6 +3646,7 @@ stats_error_parsing:
                                        goto out;
                                }
                                curproxy->options2 |= PR_O2_EXP_STS;
+                               free(curproxy->expect_str);
                                curproxy->expect_str = strdup(args[cur_arg + 1]);
                        }
                        else if (strcmp(ptr_arg, "string") == 0) {
@@ -3645,6 +3657,7 @@ stats_error_parsing:
                                        goto out;
                                }
                                curproxy->options2 |= PR_O2_EXP_STR;
+                               free(curproxy->expect_str);
                                curproxy->expect_str = strdup(args[cur_arg + 1]);
                        }
                        else if (strcmp(ptr_arg, "rstatus") == 0) {
@@ -3655,6 +3668,9 @@ stats_error_parsing:
                                        goto out;
                                }
                                curproxy->options2 |= PR_O2_EXP_RSTS;
+                               free(curproxy->expect_str);
+                               if (curproxy->expect_regex) regfree(curproxy->expect_regex);
+                               curproxy->expect_str = strdup(args[cur_arg + 1]);
                                curproxy->expect_regex = calloc(1, sizeof(regex_t));
                                if (regcomp(curproxy->expect_regex, args[cur_arg + 1], REG_EXTENDED) != 0) {
                                        Alert("parsing [%s:%d] : '%s %s %s' : bad regular expression '%s'.\n",
@@ -3671,6 +3687,9 @@ stats_error_parsing:
                                        goto out;
                                }
                                curproxy->options2 |= PR_O2_EXP_RSTR;
+                               free(curproxy->expect_str);
+                               if (curproxy->expect_regex) regfree(curproxy->expect_regex);
+                               curproxy->expect_str = strdup(args[cur_arg + 1]);
                                curproxy->expect_regex = calloc(1, sizeof(regex_t));
                                if (regcomp(curproxy->expect_regex, args[cur_arg + 1], REG_EXTENDED) != 0) {
                                        Alert("parsing [%s:%d] : '%s %s %s' : bad regular expression '%s'.\n",
@@ -3687,7 +3706,7 @@ stats_error_parsing:
                        }
                }
                else {
-                       Alert("parsing [%s:%d] : '%s' only supports 'disable-on-404', 'expect' .\n", file, linenum, args[0]);
+                       Alert("parsing [%s:%d] : '%s' only supports 'disable-on-404', 'send-state', 'expect'.\n", file, linenum, args[0]);
                        err_code |= ERR_ALERT | ERR_FATAL;
                        goto out;
                }