MEDIUM: http: The redirect strings follows the log format rules.

We handle "http-request redirect" with a log-format string now, but we
leave "redirect" unaffected.

Note that the control of the special "/" case is move from the runtime
execution to the configuration parsing. If the format rule list is
empty, the build_logline() function does nothing.

doc/configuration.txt

@@ -2768,7 +2768,8 @@ http-request { allow | deny | tarpit | auth [realm <realm>] | redirect <rule> |
     - "redirect" : this performs an HTTP redirection based on a redirect rule.
       This is exactly the same as the "redirect" statement except that it
       inserts a redirect rule which can be processed in the middle of other
-      "http-request" rules. See the "redirect" keyword for the rule's syntax.
+      "http-request" rules and that these rules use the "log-format" strings.
+      See the "redirect" keyword for the rule's syntax.
 
     - "add-header" appends an HTTP header field whose name is specified in
       <name> and whose value is defined by <fmt> which follows the log-format
@@ -4709,14 +4710,19 @@ redirect scheme   <sch> [code <code>] <option> [{if | unless} <condition>]
 
   Arguments :
     <loc>     With "redirect location", the exact value in <loc> is placed into
-              the HTTP "Location" header.
+              the HTTP "Location" header. When used in an "http-request" rule,
+              <loc> value follows the log-format rules and can include some
+              dynamic values (see Custom Log Format in section 8.2.4).
 
     <pfx>     With "redirect prefix", the "Location" header is built from the
               concatenation of <pfx> and the complete URI path, including the
               query string, unless the "drop-query" option is specified (see
               below). As a special case, if <pfx> equals exactly "/", then
               nothing is inserted before the original URI. It allows one to
-              redirect to the same URL (for instance, to insert a cookie).
+              redirect to the same URL (for instance, to insert a cookie). When
+              used in an "http-request" rule, <pfx> value follows the log-format
+              rules and can include some dynamic values (see Custom Log Format
+              in section 8.2.4).
 
     <sch>     With "redirect scheme", then the "Location" header is built by
               concatenating <sch> with "://" then the first occurrence of the
@@ -4726,7 +4732,9 @@ redirect scheme   <sch> [code <code>] <option> [{if | unless} <condition>]
               no "Host" header is found, then an empty host component will be
               returned, which most recent browsers interprete as redirecting to
               the same host. This directive is mostly used to redirect HTTP to
-              HTTPS.
+              HTTPS. When used in an "http-request" rule, <sch> value follows
+              the log-format rules and can include some dynamic values (see
+              Custom Log Format in section 8.2.4).
 
     <code>    The code is optional. It indicates which type of HTTP redirection
               is desired. Only codes 301, 302, 303, 307 and 308 are supported,
@@ -4790,6 +4798,10 @@ redirect scheme   <sch> [code <code>] <option> [{if | unless} <condition>]
   Example: redirect all HTTP traffic to HTTPS when SSL is handled by haproxy.
         redirect scheme https if !{ ssl_fc }
 
+  Example: append 'www.' prefix in front of all hosts not having it
+        http-request redirect code 301 location www.%[hdr(host)]%[req.uri] \
+          unless { hdr_beg(host) -i www }
+
   See section 7 about ACL usage.
 
 

include/proto/proto_http.h

@@ -117,8 +117,8 @@ struct http_req_rule *parse_http_req_cond(const char **args, const char *file, i
 struct http_res_rule *parse_http_res_cond(const char **args, const char *file, int linenum, struct proxy *proxy);
 void free_http_req_rules(struct list *r);
 struct chunk *http_error_message(struct session *s, int msgnum);
-struct redirect_rule *http_parse_redirect_rule(const char *file, int line, struct proxy *curproxy,
-                                               const char **args, char **errmsg);
+struct redirect_rule *http_parse_redirect_rule(const char *file, int linenum, struct proxy *curproxy,
+                                               const char **args, char **errmsg, int use_fmt);
 
 /* to be used when contents change in an HTTP message */
 #define http_msg_move_end(msg, bytes) do { \

include/types/arg.h

@@ -57,6 +57,7 @@ enum {
 	ARGC_HRQ,      /* http-request */
 	ARGC_HRS,      /* http-response */
 	ARGC_UIF,      /* unique-id-format */
+	ARGC_RDR,      /* redirect */
 };
 
 /* some types that are externally defined */

include/types/proxy.h

@@ -403,6 +403,7 @@ struct redirect_rule {
 	int type;
 	int rdr_len;
 	char *rdr_str;
+	struct list rdr_fmt;
 	int code;
 	unsigned int flags;
 	int cookie_len;

src/cfgparse.c

@@ -2770,7 +2770,7 @@ int cfg_parse_listen(const char *file, int linenum, char **args, int kwm)
 			goto out;
 		}
 
-		if ((rule = http_parse_redirect_rule(file, linenum, curproxy, (const char **)args + 1, &errmsg)) == NULL) {
+		if ((rule = http_parse_redirect_rule(file, linenum, curproxy, (const char **)args + 1, &errmsg, 0)) == NULL) {
 			Alert("parsing [%s:%d] : error detected in %s '%s' while parsing redirect rule : %s.\n",
 			      file, linenum, proxy_type_str(curproxy), curproxy->id, errmsg);
 			err_code |= ERR_ALERT | ERR_FATAL;

src/haproxy.c

@@ -1073,6 +1073,10 @@ void deinit(void)
 				free(rdr->cond);
 			}
 			free(rdr->rdr_str);
+			list_for_each_entry_safe(lf, lfb, &rdr->rdr_fmt, list) {
+				LIST_DEL(&lf->list);
+				free(lf);
+			}
 			free(rdr);
 		}
 

src/log.c

@@ -177,6 +177,8 @@ static inline const char *fmt_directive(const struct proxy *curproxy)
 		return "stick";
 	case ARGC_TRK:
 		return "track-sc"; break;
+	case ARGC_RDR:
+		return "redirect"; break;
 	case ARGC_ACL:
 		return "acl"; break;
 	default:

src/proto_http.c

@@ -3340,6 +3340,7 @@ static int http_apply_redirect_rule(struct redirect_rule *rule, struct session *
 {
 	struct http_msg *msg = &txn->req;
 	const char *msg_fmt;
+	const char *location;
 
 	/* build redirect message */
 	switch(rule->code) {
@@ -3364,6 +3365,8 @@ static int http_apply_redirect_rule(struct redirect_rule *rule, struct session *
 	if (unlikely(!chunk_strcpy(&trash, msg_fmt)))
 		return 0;
 
+	location = trash.str + trash.len;
+
 	switch(rule->type) {
 	case REDIRECT_TYPE_SCHEME: {
 		const char *path;
@@ -3399,6 +3402,7 @@ static int http_apply_redirect_rule(struct redirect_rule *rule, struct session *
 			pathlen = 1;
 		}
 
+		if (rule->rdr_str) { /* this is an old "redirect" rule */
 			/* check if we can add scheme + "://" + host + path */
 			if (trash.len + rule->rdr_len + 3 + hostlen + pathlen > trash.size - 4)
 				return 0;
@@ -3406,7 +3410,15 @@ static int http_apply_redirect_rule(struct redirect_rule *rule, struct session *
 			/* add scheme */
 			memcpy(trash.str + trash.len, rule->rdr_str, rule->rdr_len);
 			trash.len += rule->rdr_len;
+		}
+		else {
+			/* add scheme with executing log format */
+			trash.len += build_logline(s, trash.str + trash.len, trash.size - trash.len, &rule->rdr_fmt);
 
+			/* check if we can add scheme + "://" + host + path */
+			if (trash.len + 3 + hostlen + pathlen > trash.size - 4)
+				return 0;
+		}
 		/* add "://" */
 		memcpy(trash.str + trash.len, "://", 3);
 		trash.len += 3;
@@ -3419,7 +3431,7 @@ static int http_apply_redirect_rule(struct redirect_rule *rule, struct session *
 		memcpy(trash.str + trash.len, path, pathlen);
 		trash.len += pathlen;
 
-		/* append a slash at the end of the location is needed and missing */
+		/* append a slash at the end of the location if needed and missing */
 		if (trash.len && trash.str[trash.len - 1] != '/' &&
 		    (rule->flags & REDIRECT_FLAG_APPEND_SLASH)) {
 			if (trash.len > trash.size - 5)
@@ -3453,6 +3465,7 @@ static int http_apply_redirect_rule(struct redirect_rule *rule, struct session *
 			pathlen = 1;
 		}
 
+		if (rule->rdr_str) { /* this is an old "redirect" rule */
 			if (trash.len + rule->rdr_len + pathlen > trash.size - 4)
 				return 0;
 
@@ -3464,12 +3477,21 @@ static int http_apply_redirect_rule(struct redirect_rule *rule, struct session *
 				memcpy(trash.str + trash.len, rule->rdr_str, rule->rdr_len);
 				trash.len += rule->rdr_len;
 			}
+		}
+		else {
+			/* add prefix with executing log format */
+			trash.len += build_logline(s, trash.str + trash.len, trash.size - trash.len, &rule->rdr_fmt);
+
+			/* Check length */
+			if (trash.len + pathlen > trash.size - 4)
+				return 0;
+		}
 
 		/* add path */
 		memcpy(trash.str + trash.len, path, pathlen);
 		trash.len += pathlen;
 
-		/* append a slash at the end of the location is needed and missing */
+		/* append a slash at the end of the location if needed and missing */
 		if (trash.len && trash.str[trash.len - 1] != '/' &&
 		    (rule->flags & REDIRECT_FLAG_APPEND_SLASH)) {
 			if (trash.len > trash.size - 5)
@@ -3482,12 +3504,22 @@ static int http_apply_redirect_rule(struct redirect_rule *rule, struct session *
 	}
 	case REDIRECT_TYPE_LOCATION:
 	default:
+		if (rule->rdr_str) { /* this is an old "redirect" rule */
 			if (trash.len + rule->rdr_len > trash.size - 4)
 				return 0;
 
 			/* add location */
 			memcpy(trash.str + trash.len, rule->rdr_str, rule->rdr_len);
 			trash.len += rule->rdr_len;
+		}
+		else {
+			/* add location with executing log format */
+			trash.len += build_logline(s, trash.str + trash.len, trash.size - trash.len, &rule->rdr_fmt);
+
+			/* Check left length */
+			if (trash.len > trash.size - 4)
+				return 0;
+		}
 		break;
 	}
 
@@ -3509,7 +3541,7 @@ static int http_apply_redirect_rule(struct redirect_rule *rule, struct session *
 	/* let's log the request time */
 	s->logs.tv_request = now;
 
-	if (rule->rdr_len >= 1 && *rule->rdr_str == '/' &&
+	if (*location == '/' &&
 	    (msg->flags & HTTP_MSGF_XFER_LEN) &&
 	    !(msg->flags & HTTP_MSGF_TE_CHNK) && !txn->req.body_len &&
 	    ((txn->flags & TX_CON_WANT_MSK) == TX_CON_WANT_SCL ||
@@ -8474,7 +8506,7 @@ struct http_req_rule *parse_http_req_cond(const char **args, const char *file, i
 		struct redirect_rule *redir;
 		char *errmsg = NULL;
 
-		if ((redir = http_parse_redirect_rule(file, linenum, proxy, (const char **)args + 1, &errmsg)) == NULL) {
+		if ((redir = http_parse_redirect_rule(file, linenum, proxy, (const char **)args + 1, &errmsg, 1)) == NULL) {
 			Alert("parsing [%s:%d] : error detected in %s '%s' while parsing 'http-request %s' rule : %s.\n",
 			      file, linenum, proxy_type_str(proxy), proxy->id, args[0], errmsg);
 			goto out_err;
@@ -8670,10 +8702,11 @@ struct http_res_rule *parse_http_res_cond(const char **args, const char *file, i
 }
 
 /* Parses a redirect rule. Returns the redirect rule on success or NULL on error,
- * with <err> filled with the error message.
+ * with <err> filled with the error message. If <use_fmt> is not null, builds a
+ * dynamic log-format rule instead of a static string.
  */
 struct redirect_rule *http_parse_redirect_rule(const char *file, int linenum, struct proxy *curproxy,
-                                               const char **args, char **errmsg)
+                                               const char **args, char **errmsg, int use_fmt)
 {
 	struct redirect_rule *rule;
 	int cur_arg;
@@ -8771,8 +8804,27 @@ struct redirect_rule *http_parse_redirect_rule(const char *file, int linenum, st
 
 	rule = (struct redirect_rule *)calloc(1, sizeof(*rule));
 	rule->cond = cond;
+
+	if (!use_fmt) {
+		/* old-style static redirect rule */
 		rule->rdr_str = strdup(destination);
 		rule->rdr_len = strlen(destination);
+	}
+	else {
+		/* log-format based redirect rule */
+		LIST_INIT(&rule->rdr_fmt);
+
+		/* Parse destination. Note that in the REDIRECT_TYPE_PREFIX case,
+		 * if prefix == "/", we don't want to add anything, otherwise it
+		 * makes it hard for the user to configure a self-redirection.
+		 */
+		proxy->conf.args.ctx = ARGC_RDR;
+		if (!(type == REDIRECT_TYPE_PREFIX && destination[0] == '/' && destination[1] == '\0')) {
+			parse_logformat_string(destination, curproxy, &rule->rdr_fmt, 0,
+			                       (curproxy->cap & PR_CAP_FE) ? SMP_VAL_FE_HRQ_HDR : SMP_VAL_BE_HRQ_HDR);
+		}
+	}
+
 	if (cookie) {
 		/* depending on cookie_set, either we want to set the cookie, or to clear it.
 		 * a clear consists in appending "; path=/; Max-Age=0;" at the end.

src/sample.c

@@ -901,6 +901,7 @@ int smp_resolve_args(struct proxy *p)
 		case ARGC_HRQ: where = "in http-request header format string in"; break;
 		case ARGC_HRS: where = "in http-response header format string in"; break;
 		case ARGC_UIF: where = "in unique-id-format string in"; break;
+		case ARGC_RDR: where = "in redirect format string in"; break;
 		case ARGC_ACL: ctx = "ACL keyword"; break;
 		}