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res_fax_spandsp: Fix crash when passing ulaw/alaw data to spandsp 

When acting as a T.38 fax gateway, res_fax_spandsp would at times cause a crash
in libspandsp. This would occur when, during fax tone detection, a ulaw/alaw
frame would be passed to modem_connect_tones_rx. That particular routine
expects the data to be in slin format. This patch looks at the frame type and,
if the data is ulaw/alaw, converts the format to slin before passing it to
modem_connect_tones_rx.

Review: https://reviewboard.asterisk.org/r/3296

(closes issue ASTERISK-20149)
Reported by: Alexandr Gordeev
Tested by: Michal Rybarik
patches:
  spandsp_g711decode.diff uploaded by Michal Rybarik (license 6578)
........

Merged revisions 409990 from http://svn.asterisk.org/svn/asterisk/branches/11
........

Merged revisions 409991 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@409996 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Matthew Jordan 2014-03-06 02:22:59 +00:00
parent 77ad5ec2e3
commit 38da8d2fda
1 changed files with 26 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
res/res_fax_spandsp.c
View File

@ -649,6 +649,8 @@ static void spandsp_v21_tone(void *data, int code, int level, int delay)
static int spandsp_v21_detect(struct ast_fax_session *s, const struct ast_frame *f) {
struct spandsp_pvt *p = s->tech_pvt;
int16_t *slndata;
g711_state_t *decoder;
if (p->v21_detected) {
return 0;
@ -659,10 +661,33 @@ static int spandsp_v21_detect(struct ast_fax_session *s, const struct ast_frame
return -1;
}
modem_connect_tones_rx(p->tone_state, f->data.ptr, f->samples);
ast_debug(5, "frame={ datalen=%d, samples=%d, mallocd=%d, src=%s, flags=%d, ts=%ld, len=%ld, seqno=%d, data.ptr=%p, subclass.format.id=%d }\n", f->datalen, f->samples, f->mallocd, f->src, f->flags, f->ts, f->len, f->seqno, f->data.ptr, f->subclass.format.id);
/* slinear frame can be passed to spandsp */
if (f->subclass.format.id == AST_FORMAT_SLINEAR) {
modem_connect_tones_rx(p->tone_state, f->data.ptr, f->samples);
/* alaw/ulaw frame must be converted to slinear before passing to spandsp */
} else if (f->subclass.format.id == AST_FORMAT_ALAW || f->subclass.format.id == AST_FORMAT_ULAW) {
if (!(slndata = ast_malloc(sizeof(*slndata) * f->samples))) {
return -1;
}
decoder = g711_init(NULL, (f->subclass.format.id == AST_FORMAT_ALAW ? G711_ALAW : G711_ULAW));
g711_decode(decoder, slndata, f->data.ptr, f->samples);
ast_debug(5, "spandsp transcoding frame from %s to slinear for v21 detection\n", (f->subclass.format.id == AST_FORMAT_ALAW ? "G711_ALAW" : "G711_ULAW"));
modem_connect_tones_rx(p->tone_state, slndata, f->samples);
g711_release(decoder);
ast_free(slndata);
/* frame in other formats cannot be passed to spandsp, it could cause segfault */
} else {
ast_log(LOG_WARNING, "Unknown frame format %d, v.21 detection skipped\n", f->subclass.format.id);
return -1;
}
if (p->v21_detected) {
s->details->option.v21_detected = 1;
ast_debug(5, "v.21 detected\n");
}
return 0;