From: David M. Lee <dlee@digium.com>
Date: Fri, 5 Oct 2012 20:12:49 +0000 (+0000)
Subject: Improve AMI long line error handling
X-Git-Tag: certified/1.8.15-cert1-rc1~3^2~13
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d1f6dce6d5040530a6d22f09f86cd1b70eeb8fdf;p=thirdparty%2Fasterisk.git

Improve AMI long line error handling

In AMI's parser, when it receives a long line (> 1024 characters), it discards
that line, but continues to process the message normally.

Typically, this is not a problem because a) who has lines that long and b)
usually a discarded line results in an invalid message. But if that line is
specifying an optional field, then the message will be processed, you get a
'Response: Success', but things don't work the way you expected them to.

This patch changes the behavior when a line-too-long parse error occurs.

* Changes the log message to avoid way-too-long (and truncated anyways) log
  messages
* Adds a 'parsing' status flag to Response: Success
* Sets parsing = MESSAGE_LINE_TOO_LONG if, well, a line is too long
* Responds with an appropriate error if parsing != MESSAGE_OKAY

(closes issue AST-961)
Reported by: John Bigelow
Review: https://reviewboard.asterisk.org/r/2142/


git-svn-id: https://origsvn.digium.com/svn/asterisk/certified/branches/1.8.15@374569 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---

diff --git a/main/manager.c b/main/manager.c
index dafc0c0f1e..e8cd52adc4 100644
--- a/main/manager.c
+++ b/main/manager.c
@@ -992,6 +992,11 @@ struct mansession_session {
 	AST_LIST_ENTRY(mansession_session) list;
 };
 
+enum mansession_message_parsing {
+	MESSAGE_OKAY,
+	MESSAGE_LINE_TOO_LONG
+};
+
 /* In case you didn't read that giant block of text above the mansession_session struct, the
  * 'mansession' struct is named this solely to keep the API the same in Asterisk. This structure really
  * represents data that is different from Manager action to Manager action. The mansession_session pointer
@@ -1002,6 +1007,7 @@ struct mansession {
 	struct ast_tcptls_session_instance *tcptls_session;
 	FILE *f;
 	int fd;
+	enum mansession_message_parsing parsing;
 	int write_error:1;
 	struct manager_custom_hook *hook;
 	ast_mutex_t lock;
@@ -4783,8 +4789,9 @@ static int get_input(struct mansession *s, char *output)
 	}
 	if (s->session->inlen >= maxlen) {
 		/* no crlf found, and buffer full - sorry, too long for us */
-		ast_log(LOG_WARNING, "Dumping long line with no return from %s: %s\n", ast_inet_ntoa(s->session->sin.sin_addr), src);
+		ast_log(LOG_WARNING, "Discarding message from %s. Line too long: %.25s...\n", ast_inet_ntoa(s->session->sin.sin_addr), src);
 		s->session->inlen = 0;
+		s->parsing = MESSAGE_LINE_TOO_LONG;
 	}
 	res = 0;
 	while (res == 0) {
@@ -4841,6 +4848,23 @@ static int get_input(struct mansession *s, char *output)
 	return res;
 }
 
+/*!
+ * \internal
+ * \brief Error handling for sending parse errors. This function handles locking, and clearing the
+ * parse error flag.
+ *
+ * \param s AMI session to process action request.
+ * \param m Message that's in error.
+ * \param error Error message to send.
+ */
+static void handle_parse_error(struct mansession *s, struct message *m, char *error)
+{
+	mansession_lock(s);
+	astman_send_error(s, m, error);
+	s->parsing = MESSAGE_OKAY;
+	mansession_unlock(s);
+}
+
 /*!
  * \internal
  * \brief Read and process an AMI action request.
@@ -4894,7 +4918,15 @@ static int do_message(struct mansession *s)
 					mansession_unlock(s);
 					res = 0;
 				} else {
-					res = process_message(s, &m) ? -1 : 0;
+					switch (s->parsing) {
+					case MESSAGE_OKAY:
+						res = process_message(s, &m) ? -1 : 0;
+						break;
+					case MESSAGE_LINE_TOO_LONG:
+						handle_parse_error(s, &m, "Failed to parse message: line too long");
+						res = 0;
+						break;
+					}
 				}
 				break;
 			} else if (m.hdrcount < ARRAY_LEN(m.headers)) {