MINOR: proxy/http-ana: Add support of extra attributes for the cookie directive

It is now possible to insert any attribute when a cookie is inserted by
HAProxy. Any value may be set, no check is performed except the syntax validity
(CTRL chars and ';' are forbidden). For instance, it may be used to add the
SameSite attribute:

    cookie SRV insert attr "SameSite=Strict"

The attr option may be repeated to add several attributes.

This patch should fix the issue #361.

doc/configuration.txt

@@ -3340,7 +3340,7 @@ compression offload
 cookie <name> [ rewrite | insert | prefix ] [ indirect ] [ nocache ]
               [ postonly ] [ preserve ] [ httponly ] [ secure ]
               [ domain <domain> ]* [ maxidle <idle> ] [ maxlife <life> ]
-              [ dynamic ]
+              [ dynamic ] [ attr <value> ]*
   Enable cookie-based persistence in a backend.
   May be used in sections :   defaults | frontend | listen | backend
                                  yes   |    no    |   yes  |   yes
@@ -3499,6 +3499,11 @@ cookie <name> [ rewrite | insert | prefix ] [ indirect ] [ nocache ]
               The cookie will be regenerated each time the IP address change,
               and is only generated for IPv4/IPv6.
 
+    attr      This option tells haproxy to add an extra attribute when a
+              cookie is inserted. The attribute value can contain any
+              characters except control ones or ";". This option may be
+              repeated.
+
   There can be only one persistence cookie per HTTP backend, and it can be
   declared in a defaults section. The value of the cookie will be the value
   indicated after the "cookie" keyword in a "server" statement. If no cookie

include/types/proxy.h

@@ -338,6 +338,7 @@ struct proxy {
 	int  cookie_len;			/* strlen(cookie_name), computed only once */
 	char *cookie_domain;			/* domain used to insert the cookie */
 	char *cookie_name;			/* name of the cookie to look for */
+	char *cookie_attrs;                     /* list of attributes to add to the cookie */
 	char *dyncookie_key;			/* Secret key used to generate dynamic persistent cookies */
 	unsigned int cookie_maxidle;		/* max idle time for this cookie */
 	unsigned int cookie_maxlife;		/* max life time for this cookie */

src/cfgparse-listen.c

@@ -326,6 +326,8 @@ int cfg_parse_listen(const char *file, int linenum, char **args, int kwm)
 				 curproxy->rdp_cookie_name = strdup(defproxy.rdp_cookie_name);
 			curproxy->rdp_cookie_len = defproxy.rdp_cookie_len;
 
+			if (defproxy.cookie_attrs)
+				curproxy->cookie_attrs = strdup(defproxy.cookie_attrs);
 
 			if (defproxy.lbprm.arg_str)
 				curproxy->lbprm.arg_str = strdup(defproxy.lbprm.arg_str);
@@ -476,6 +478,7 @@ int cfg_parse_listen(const char *file, int linenum, char **args, int kwm)
 		free(defproxy.rdp_cookie_name);
 		free(defproxy.dyncookie_key);
 		free(defproxy.cookie_domain);
+		free(defproxy.cookie_attrs);
 		free(defproxy.lbprm.arg_str);
 		free(defproxy.capture_name);
 		free(defproxy.monitor_uri);
@@ -988,9 +991,34 @@ int cfg_parse_listen(const char *file, int linenum, char **args, int kwm)
 					err_code |= ERR_WARN;
 				curproxy->ck_opts |= PR_CK_DYNAMIC;
 			}
+			else if (!strcmp(args[cur_arg], "attr")) {
+				char *val;
+				if (!*args[cur_arg + 1]) {
+					ha_alert("parsing [%s:%d]: '%s' expects <value> as argument.\n",
+						 file, linenum, args[cur_arg]);
+					err_code |= ERR_ALERT | ERR_FATAL;
+					goto out;
+				}
+				val = args[cur_arg + 1];
+				while (*val) {
+					if (iscntrl(*val) || *val == ';') {
+						ha_alert("parsing [%s:%d]: character '%%x%02X' is not permitted in attribute value.\n",
+							 file, linenum, *val);
+						err_code |= ERR_ALERT | ERR_FATAL;
+						goto out;
+					}
+					val++;
+				}
+				/* don't add ';' for the first attribute */
+				if (!curproxy->cookie_attrs)
+					curproxy->cookie_attrs = strdup(args[cur_arg + 1]);
+				else
+					memprintf(&curproxy->cookie_attrs, "%s; %s", curproxy->cookie_attrs, args[cur_arg + 1]);
+				cur_arg++;
+			}
 
 			else {
-				ha_alert("parsing [%s:%d] : '%s' supports 'rewrite', 'insert', 'prefix', 'indirect', 'nocache', 'postonly', 'domain', 'maxidle', 'dynamic' and 'maxlife' options.\n",
+				ha_alert("parsing [%s:%d] : '%s' supports 'rewrite', 'insert', 'prefix', 'indirect', 'nocache', 'postonly', 'domain', 'maxidle', 'dynamic', 'maxlife' and 'attr' options.\n",
 					 file, linenum, args[0]);
 				err_code |= ERR_ALERT | ERR_FATAL;
 				goto out;

src/haproxy.c

@@ -2339,6 +2339,7 @@ void deinit(void)
 		free(p->check_req);
 		free(p->cookie_name);
 		free(p->cookie_domain);
+		free(p->cookie_attrs);
 		free(p->lbprm.arg_str);
 		free(p->capture_name);
 		free(p->monitor_uri);

src/http_ana.c

@@ -2068,6 +2068,9 @@ int http_process_res_common(struct stream *s, struct channel *rep, int an_bit, s
 		if (s->be->ck_opts & PR_CK_SECURE)
 			chunk_appendf(&trash, "; Secure");
 
+		if (s->be->cookie_attrs)
+			chunk_appendf(&trash, "; %s", s->be->cookie_attrs);
+
 		if (unlikely(!http_add_header(htx, ist("Set-Cookie"), ist2(trash.area, trash.data))))
 			goto return_int_err;