Harald Welte has submitted this change and it was merged.
Change subject: ggsn: Parse PCO_IPCP
......................................................................
ggsn: Parse PCO_IPCP
Improvements include:
- Use Identifier received from request instead of using hardcoded id=0.
- Don't add DNS to response if they were not included in request.
Change-Id: Ic8aa5d634e526683b2ad8ed5d14088e171c41c98
---
M ggsn/ggsn.c
1 file changed, 53 insertions(+), 15 deletions(-)
Approvals:
Harald Welte: Looks good to me, approved
Jenkins Builder: Verified
diff --git a/ggsn/ggsn.c b/ggsn/ggsn.c
index 6645d4c..0ff292d 100644
--- a/ggsn/ggsn.c
+++ b/ggsn/ggsn.c
@@ -377,6 +377,41 @@
#include <osmocom/gsm/tlv.h>
+/* RFC 1332 */
+enum ipcp_options {
+ IPCP_OPT_IPADDR = 3,
+ IPCP_OPT_PRIMARY_DNS = 129,
+ IPCP_OPT_SECONDARY_DNS = 131,
+};
+
+struct ipcp_option_hdr {
+ uint8_t type;
+ uint8_t len;
+ uint8_t data[0];
+};
+
+struct ipcp_hdr {
+ uint8_t code;
+ uint8_t id;
+ uint16_t len;
+ uint8_t options[0];
+};
+
+/* determine if IPCP contains given option */
+static struct ipcp_option_hdr *ipcp_contains_option(struct ipcp_hdr *ipcp,
enum ipcp_options opt)
+{
+ uint8_t *cur = ipcp->options;
+
+ /* iterate over Options and check if protocol contained */
+ while (cur + 2 <= ((uint8_t *)ipcp) + ipcp->len) {
+ struct ipcp_option_hdr *cur_opt = (struct ipcp_option_hdr *)
cur;
+ if (cur_opt->type == opt)
+ return cur_opt;
+ cur += cur_opt->len;
+ }
+ return NULL;
+}
+
/* 3GPP TS 24.008 10.6.5.3 */
enum pco_protocols {
PCO_P_LCP = 0xC021,
@@ -410,7 +445,7 @@
};
/* determine if PCO contains given protocol */
-static bool pco_contains_proto(struct ul255_t *pco, uint16_t prot)
+static uint8_t *pco_contains_proto(struct ul255_t *pco, uint16_t prot)
{
uint8_t *cur = pco->v + 1;
@@ -419,10 +454,10 @@
uint16_t cur_prot = osmo_load16be(cur);
uint8_t cur_len = cur[2];
if (cur_prot == prot)
- return true;
+ return cur;
cur += cur_len + 3;
}
- return false;
+ return NULL;
}
/*! Get the peer of pdp based on IP version used.
@@ -458,30 +493,36 @@
return false;
}
-/* construct an IPCP PCO from up to two given DNS addreses */
-static int build_ipcp_pco(struct msgb *msg, uint8_t id, const struct in46_addr
*dns1,
- const struct in46_addr *dns2)
+/* construct an IPCP PCO response from request*/
+static int build_ipcp_pco(struct apn_ctx *apn, struct pdp_t *pdp, struct msgb
*msg)
{
- uint8_t *len1, *len2;
+ const struct in46_addr *dns1 = &apn->v4.cfg.dns[0];
+ const struct in46_addr *dns2 = &apn->v4.cfg.dns[1];
+ struct ipcp_hdr *ipcp;
+ uint8_t *len1, *len2, *pco_ipcp;
uint8_t *start = msg->tail;
unsigned int len_appended;
+
+ if (!(pco_ipcp = pco_contains_proto(&pdp->pco_req, PCO_P_IPCP)))
+ return 0;
+ ipcp = (struct ipcp_hdr*) (pco_ipcp + 3); /* 2=type + 1=len */
/* Three byte T16L header */
msgb_put_u16(msg, 0x8021); /* IPCP */
len1 = msgb_put(msg, 1); /* Length of contents: delay */
msgb_put_u8(msg, 0x02); /* ACK */
- msgb_put_u8(msg, id); /* ID: Needs to match request */
+ msgb_put_u8(msg, ipcp->id); /* ID: Needs to match request */
msgb_put_u8(msg, 0x00); /* Length MSB */
len2 = msgb_put(msg, 1); /* Length LSB: delay */
- if (dns1 && dns1->len == 4) {
+ if (dns1->len == 4 && ipcp_contains_option(ipcp, IPCP_OPT_PRIMARY_DNS))
{
msgb_put_u8(msg, 0x81); /* DNS1 Tag */
msgb_put_u8(msg, 2 + dns1->len);/* DNS1 Length, incl. TL */
msgb_put_u32(msg, ntohl(dns1->v4.s_addr));
}
- if (dns2 && dns2->len == 4) {
+ if (dns2->len == 4 && ipcp_contains_option(ipcp,
IPCP_OPT_SECONDARY_DNS)) {
msgb_put_u8(msg, 0x83); /* DNS2 Tag */
msgb_put_u8(msg, 2 + dns2->len);/* DNS2 Length, incl. TL */
msgb_put_u32(msg, ntohl(dns2->v4.s_addr));
@@ -504,11 +545,8 @@
OSMO_ASSERT(msg);
msgb_put_u8(msg, 0x80); /* ext-bit + configuration protocol byte */
- /* FIXME: also check if primary / secondary DNS was requested */
- if (pdp_has_v4(pdp) && pco_contains_proto(&pdp->pco_req, PCO_P_IPCP)) {
- /* FIXME: properly implement this for IPCP */
- build_ipcp_pco(msg, 0, &apn->v4.cfg.dns[0],
&apn->v4.cfg.dns[1]);
- }
+ if (pdp_has_v4(pdp))
+ build_ipcp_pco(apn, pdp, msg);
if (pco_contains_proto(&pdp->pco_req, PCO_P_DNS_IPv6_ADDR)) {
for (i = 0; i < ARRAY_SIZE(apn->v6.cfg.dns); i++) {
--
To view, visit https://gerrit.osmocom.org/6101
To unsubscribe, visit https://gerrit.osmocom.org/settings
Gerrit-MessageType: merged
Gerrit-Change-Id: Ic8aa5d634e526683b2ad8ed5d14088e171c41c98
Gerrit-PatchSet: 2
Gerrit-Project: osmo-ggsn
Gerrit-Branch: master
Gerrit-Owner: Pau Espin Pedrol <[email protected]>
Gerrit-Reviewer: Harald Welte <[email protected]>
Gerrit-Reviewer: Jenkins Builder
