MEDIUM: http: Add a ruleset evaluated on all responses just before forwarding
This patch introduces the 'http-after-response' rules. These rules are evaluated
at the end of the response analysis, just before the data forwarding, on ALL
HTTP responses, the server ones but also all responses generated by
HAProxy. Thanks to this ruleset, it is now possible for instance to add some
headers to the responses generated by the stats applet. Following actions are
supported :
* allow
* add-header
* del-header
* replace-header
* replace-value
* set-header
* set-status
* set-var
* strict-mode
* unset-var
diff --git a/src/http_rules.c b/src/http_rules.c
index f1a187b..2e58ec2 100644
--- a/src/http_rules.c
+++ b/src/http_rules.c
@@ -47,6 +47,11 @@
.list = LIST_HEAD_INIT(http_res_keywords.list)
};
+/* List head of all known action keywords for "http-after-response" */
+struct action_kw_list http_after_res_keywords = {
+ .list = LIST_HEAD_INIT(http_after_res_keywords.list)
+};
+
/*
* Return the struct http_req_action_kw associated to a keyword.
*/
@@ -63,6 +68,14 @@
return action_lookup(&http_res_keywords.list, kw);
}
+/*
+ * Return the struct http_after_res_action_kw associated to a keyword.
+ */
+static struct action_kw *action_http_after_res_custom(const char *kw)
+{
+ return action_lookup(&http_after_res_keywords.list, kw);
+}
+
/* parse an "http-request" rule */
struct act_rule *parse_http_req_cond(const char **args, const char *file, int linenum, struct proxy *proxy)
{
@@ -191,6 +204,71 @@
return NULL;
}
+
+/* parse an "http-after-response" rule */
+struct act_rule *parse_http_after_res_cond(const char **args, const char *file, int linenum, struct proxy *proxy)
+{
+ struct act_rule *rule;
+ struct action_kw *custom = NULL;
+ int cur_arg;
+
+ rule = calloc(1, sizeof(*rule));
+ if (!rule) {
+ ha_alert("parsing [%s:%d]: out of memory.\n", file, linenum);
+ goto out_err;
+ }
+ rule->from = ACT_F_HTTP_RES;
+
+ if (((custom = action_http_after_res_custom(args[0])) != NULL)) {
+ char *errmsg = NULL;
+
+ cur_arg = 1;
+ /* try in the module list */
+ rule->kw = custom;
+ if (custom->parse(args, &cur_arg, proxy, rule, &errmsg) == ACT_RET_PRS_ERR) {
+ ha_alert("parsing [%s:%d] : error detected in %s '%s' while parsing 'http-after-response %s' rule : %s.\n",
+ file, linenum, proxy_type_str(proxy), proxy->id, args[0], errmsg);
+ free(errmsg);
+ goto out_err;
+ }
+ else if (errmsg) {
+ ha_warning("parsing [%s:%d] : %s.\n", file, linenum, errmsg);
+ free(errmsg);
+ }
+ }
+ else {
+ action_build_list(&http_after_res_keywords.list, &trash);
+ ha_alert("parsing [%s:%d]: 'http-after-response' expects %s%s, but got '%s'%s.\n",
+ file, linenum, *trash.area ? ", " : "", trash.area,
+ args[0], *args[0] ? "" : " (missing argument)");
+ goto out_err;
+ }
+
+ if (strcmp(args[cur_arg], "if") == 0 || strcmp(args[cur_arg], "unless") == 0) {
+ struct acl_cond *cond;
+ char *errmsg = NULL;
+
+ if ((cond = build_acl_cond(file, linenum, &proxy->acl, proxy, args+cur_arg, &errmsg)) == NULL) {
+ ha_alert("parsing [%s:%d] : error detected while parsing an 'http-after-response %s' condition : %s.\n",
+ file, linenum, args[0], errmsg);
+ free(errmsg);
+ goto out_err;
+ }
+ rule->cond = cond;
+ }
+ else if (*args[cur_arg]) {
+ ha_alert("parsing [%s:%d]: 'http-after-response %s' expects"
+ " either 'if' or 'unless' followed by a condition but found '%s'.\n",
+ file, linenum, args[0], args[cur_arg]);
+ goto out_err;
+ }
+
+ return rule;
+ out_err:
+ free(rule);
+ return NULL;
+}
+
/* Parses a redirect rule. Returns the redirect rule on success or NULL on error,
* with <err> filled with the error message. If <use_fmt> is not null, builds a
* dynamic log-format rule instead of a static string. Parameter <dir> indicates