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/branches/1.8@374570 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/main/manager.c b/main/manager.c
index 0285407d3dcde4b04a1633492bdd5a64c67fe997..d2840b09f0d828adcd1421bb573b8ff0daa3ef72 100644 (file)
--- a/main/manager.c
+++ b/main/manager.c
@@ -999,6 +999,11 @@ 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
@@ -1009,6 +1014,7 @@ 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;
@@ -1645,8 +1651,9 @@ static char *handle_showmanagers(struct ast_cli_entry *e, int cmd, struct ast_cl
 static char *handle_showmancmds(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
 {
        struct manager_action *cur;
-       struct ast_str *authority;
-#define HSMC_FORMAT "  %-15.15s  %-15.15s  %-55.55s\n"
+       int name_len = 1;
+       int space_remaining;
+#define HSMC_FORMAT "  %-*.*s  %-*.*s\n"
        switch (cmd) {
        case CLI_INIT:
                e->command = "manager show commands";
@@ -1657,13 +1664,25 @@ static char *handle_showmancmds(struct ast_cli_entry *e, int cmd, struct ast_cli
        case CLI_GENERATE:
                return NULL;
        }
-       authority = ast_str_alloca(80);
-       ast_cli(a->fd, HSMC_FORMAT, "Action", "Privilege", "Synopsis");
-       ast_cli(a->fd, HSMC_FORMAT, "------", "---------", "--------");
 
        AST_RWLIST_RDLOCK(&actions);
        AST_RWLIST_TRAVERSE(&actions, cur, list) {
-               ast_cli(a->fd, HSMC_FORMAT, cur->action, authority_to_str(cur->authority, &authority), cur->synopsis);
+               int incoming_len = strlen(cur->action);
+               if (incoming_len > name_len) {
+                       name_len = incoming_len;
+               }
+       }
+
+       space_remaining = 85 - name_len;
+       if (space_remaining < 0) {
+               space_remaining = 0;
+       }
+
+       ast_cli(a->fd, HSMC_FORMAT, name_len, name_len, "Action", space_remaining, space_remaining, "Synopsis");
+       ast_cli(a->fd, HSMC_FORMAT, name_len, name_len, "------", space_remaining, space_remaining, "--------");
+
+       AST_RWLIST_TRAVERSE(&actions, cur, list) {
+               ast_cli(a->fd, HSMC_FORMAT, name_len, name_len, cur->action, space_remaining, space_remaining, cur->synopsis);
        }
        AST_RWLIST_UNLOCK(&actions);
 
@@ -4793,8 +4812,9 @@ 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) {
@@ -4851,6 +4871,23 @@ 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.
@@ -4904,7 +4941,15 @@ 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)) {