[Asterisk-code-review] res_pjsip_diversion: Fix adding more than one histinfo to Supported (asterisk[17.9])

[Joshua Colp]

Hello Ivan Poddubny,

I'd like you to do a code review. Please visit

    https://gerrit.asterisk.org/c/asterisk/+/15463

to review the following change.


Change subject: res_pjsip_diversion: Fix adding more than one histinfo to Supported
......................................................................

res_pjsip_diversion: Fix adding more than one histinfo to Supported

New responses sent within a PJSIP sessions are based on those that were
sent before. Therefore, adding/modifying a header once causes it to be
sent on all responses that follow.

Sending 181 Call Is Being Forwarded many times first adds "histinfo"
duplicated more and more, and eventually overflows past the array
boundary.

This commit adds a check preventing adding "histinfo" more than once,
and skipping it if there is no more space in the header.

Similar overflow situations can also occur in res_pjsip_path and
res_pjsip_outbound_registration so those were also modified to
check the bounds and suppress duplicate Supported values.

ASTERISK-29227
Reported by: Ivan Poddubny

Change-Id: Id43704a1f1a0293e35cc7f844026f0b04f2ac322
---
M res/res_pjsip_diversion.c
M res/res_pjsip_outbound_registration.c
M res/res_pjsip_path.c
3 files changed, 38 insertions(+), 0 deletions(-)



  git pull ssh://gerrit.asterisk.org:29418/asterisk refs/changes/63/15463/1

diff --git a/res/res_pjsip_diversion.c b/res/res_pjsip_diversion.c
index 24d1781..1cc6e08 100644
--- a/res/res_pjsip_diversion.c
+++ b/res/res_pjsip_diversion.c
@@ -120,6 +120,7 @@
 static int add_supported(pjsip_tx_data *tdata)
 {
 	pjsip_supported_hdr *hdr;
+	unsigned int i;
 
 	hdr = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_SUPPORTED, NULL);
 	if (!hdr) {
@@ -132,6 +133,19 @@
 		pjsip_msg_add_hdr(tdata->msg, (pjsip_hdr *)hdr);
 	}
 
+	/* Asterisk can send multiple "181 Call forwarded" in a single session,
+	 * we might have already modified Supported before
+	 */
+	for (i = 0; i < hdr->count; ++i) {
+		if (pj_stricmp(&hdr->values[i], &HISTINFO_SUPPORTED_NAME) == 0) {
+			return 0;
+		}
+	}
+
+	if (hdr->count >= PJSIP_GENERIC_ARRAY_MAX_COUNT) {
+		return -1;
+	}
+
 	/* add on to the existing Supported header */
 	pj_strassign(&hdr->values[hdr->count++], &HISTINFO_SUPPORTED_NAME);
 
diff --git a/res/res_pjsip_outbound_registration.c b/res/res_pjsip_outbound_registration.c
index 2c58986..99da044 100644
--- a/res/res_pjsip_outbound_registration.c
+++ b/res/res_pjsip_outbound_registration.c
@@ -615,6 +615,7 @@
 static int add_to_supported_header(pjsip_tx_data *tdata, pj_str_t *name)
 {
 	pjsip_supported_hdr *hdr;
+	int i;
 
 	hdr = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_SUPPORTED, NULL);
 	if (!hdr) {
@@ -628,6 +629,17 @@
 		pjsip_msg_add_hdr(tdata->msg, (pjsip_hdr *)hdr);
 	}
 
+	/* Don't add the value if it's already there */
+	for (i = 0; i < hdr->count; ++i) {
+		if (pj_stricmp(&hdr->values[i], name) == 0) {
+			return 1;
+		}
+	}
+
+	if (hdr->count >= PJSIP_GENERIC_ARRAY_MAX_COUNT) {
+		return 0;
+	}
+
 	/* add on to the existing Supported header */
 	pj_strassign(&hdr->values[hdr->count++], name);
 
diff --git a/res/res_pjsip_path.c b/res/res_pjsip_path.c
index adc5a8c..9f48009 100644
--- a/res/res_pjsip_path.c
+++ b/res/res_pjsip_path.c
@@ -123,6 +123,7 @@
 static int add_supported(pjsip_tx_data *tdata)
 {
 	pjsip_supported_hdr *hdr;
+	int i;
 
 	hdr = pjsip_msg_find_hdr(tdata->msg, PJSIP_H_SUPPORTED, NULL);
 	if (!hdr) {
@@ -135,6 +136,17 @@
 		pjsip_msg_add_hdr(tdata->msg, (pjsip_hdr *)hdr);
 	}
 
+	/* Don't add the value if it's already there */
+	for (i = 0; i < hdr->count; ++i) {
+		if (pj_stricmp(&hdr->values[i], &PATH_SUPPORTED_NAME) == 0) {
+			return 0;
+		}
+	}
+
+	if (hdr->count >= PJSIP_GENERIC_ARRAY_MAX_COUNT) {
+		return -1;
+	}
+
 	/* add on to the existing Supported header */
 	pj_strassign(&hdr->values[hdr->count++], &PATH_SUPPORTED_NAME);
 

-- 
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Gerrit-Project: asterisk
Gerrit-Branch: 17.9
Gerrit-Change-Id: Id43704a1f1a0293e35cc7f844026f0b04f2ac322
Gerrit-Change-Number: 15463
Gerrit-PatchSet: 1
Gerrit-Owner: Joshua Colp <jcolp at sangoma.com>
Gerrit-Reviewer: Ivan Poddubny <ivan.poddubny at gmail.com>
Gerrit-MessageType: newchange
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