Properly handle partial reads from fgets() when handling AGIs.

When fgets() failed with EAGAIN, we were continually decrementing the available
space left in our buffer, resulting in botched command handling.

(closes issue #16032)
Reported by: notahat
Patches:
      agi_buffer_patch2.diff uploaded by fnordian (license 110)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.2@302548 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/res/res_agi.c b/res/res_agi.c
index 2fbb837b44b8c02cd4ba5beb6c5949ca5b8c8bac..c3548906c306945389289248eebf49472508d019 100644 (file)
--- a/res/res_agi.c
+++ b/res/res_agi.c
@@ -2920,7 +2920,7 @@ static enum agi_result run_agi(struct ast_channel *chan, char *request, AGI *agi
                        retry = AGI_NANDFS_RETRY;
                        buf[0] = '\0';
 
-                       while (buflen < (len - 1)) {
+                       while (len > 1) {
                                res = fgets(buf + buflen, len, readf);
                                if (feof(readf))
                                        break;
@@ -2931,7 +2931,7 @@ static enum agi_result run_agi(struct ast_channel *chan, char *request, AGI *agi
                                buflen = strlen(buf);
                                if (buflen && buf[buflen - 1] == '\n')
                                        break;
-                               len -= buflen;
+                               len = sizeof(buf) - buflen;
                                if (agidebug)
                                        ast_verbose( "AGI Rx << temp buffer %s - errno %s\n", buf, strerror(errno));
                        }