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Harald Welte gerrit-no-reply at lists.osmocom.orgHarald Welte has uploaded this change for review. ( https://gerrit.osmocom.org/13606
Change subject: ggsn.c: Refactor PCO processing during PDP activation
......................................................................
ggsn.c: Refactor PCO processing during PDP activation
The existing PCO processing is implemented in a rater convoluted
way. We scan the list of PCO elements several times for different
PCO protocols. Let's change to a straight-forward model where we
simply do one iteration over the list of PCO elements and generate
responses step by step.
Change-Id: I4a7d09279b6b259e2b95f1f51159b16838b2d94c
---
M ggsn/ggsn.c
1 file changed, 96 insertions(+), 85 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-ggsn refs/changes/06/13606/1
diff --git a/ggsn/ggsn.c b/ggsn/ggsn.c
index eac7e16..c460b98 100644
--- a/ggsn/ggsn.c
+++ b/ggsn/ggsn.c
@@ -470,22 +470,6 @@
uint8_t data[0];
} __attribute__((packed));
-/* determine if PCO contains given protocol */
-static const struct pco_element *pco_contains_proto(const struct ul255_t *pco, size_t offset,
- uint16_t prot, size_t prot_minlen)
-{
- const uint8_t *cur = pco->v + 1 /*length*/ + offset;
-
- /* iterate over PCO and check if protocol contained */
- while (cur + sizeof(struct pco_element) <= pco->v + pco->l) {
- const struct pco_element *elem = (const struct pco_element *)cur;
- if (ntohs(elem->protocol_id) == prot && elem->length >= prot_minlen)
- return elem;
- cur += elem->length + sizeof(struct pco_element);
- }
- return NULL;
-}
-
/*! Get the peer of pdp based on IP version used.
* \param[in] pdp PDP context to select the peer from.
* \param[in] v4v6 IP version to select. Valid values are 4 and 6.
@@ -510,103 +494,130 @@
return NULL;
}
-/* construct an IPCP PCO response from request*/
-static void build_ipcp_pco(const struct apn_ctx *apn, struct pdp_t *pdp, struct msgb *msg)
+static void process_pco_element_ipcp(const struct pco_element *pco_elem, struct msgb *resp,
+ const struct apn_ctx *apn, struct pdp_t *pdp)
{
+ struct ippoolm_t *peer_v4 = pdp_get_peer_ipv(pdp, false);
const struct in46_addr *dns1 = &apn->v4.cfg.dns[0];
const struct in46_addr *dns2 = &apn->v4.cfg.dns[1];
- const struct pco_element *pco_ipcp;
+ uint8_t *start = resp->tail;
const uint8_t *ipcp;
uint16_t ipcp_len;
uint8_t *len1, *len2;
unsigned int len_appended;
ptrdiff_t consumed;
- size_t remain, offset = 0;
+ size_t remain;
- /* pco_contains_proto() returns a potentially unaligned pointer into pco_req->v (see OS#3194) */
- pco_ipcp = pco_contains_proto(&pdp->pco_req, offset, PCO_P_IPCP, sizeof(struct ipcp_hdr));
- while (pco_ipcp) {
- uint8_t *start = msg->tail;
+ if (!peer_v4)
+ return;
- ipcp = pco_ipcp->data;
- consumed = (ipcp - &pdp->pco_req.v[0]);
- remain = sizeof(pdp->pco_req.v) - consumed;
- ipcp_len = osmo_load16be(ipcp + 2); /* 1=code + 1=id */
- if (remain < 0 || remain < ipcp_len)
- return;
+ ipcp = pco_elem->data;
+ consumed = (ipcp - &pdp->pco_req.v[0]);
+ remain = sizeof(pdp->pco_req.v) - consumed;
+ ipcp_len = osmo_load16be(ipcp + 2); /* 1=code + 1=id */
+ if (remain < 0 || remain < ipcp_len)
+ return;
- /* Three byte T16L header */
- msgb_put_u16(msg, 0x8021); /* IPCP */
- len1 = msgb_put(msg, 1); /* Length of contents: delay */
+ /* Three byte T16L header */
+ msgb_put_u16(resp, 0x8021); /* IPCP */
+ len1 = msgb_put(resp, 1); /* Length of contents: delay */
- msgb_put_u8(msg, 0x02); /* ACK */
- msgb_put_u8(msg, ipcp[1]); /* ID: Needs to match request */
- msgb_put_u8(msg, 0x00); /* Length MSB */
- len2 = msgb_put(msg, 1); /* Length LSB: delay */
+ msgb_put_u8(resp, 0x02); /* ACK */
+ msgb_put_u8(resp, ipcp[1]); /* ID: Needs to match request */
+ msgb_put_u8(resp, 0x00); /* Length MSB */
+ len2 = msgb_put(resp, 1); /* Length LSB: delay */
- if (dns1->len == 4 && ipcp_contains_option(ipcp, ipcp_len, IPCP_OPT_PRIMARY_DNS, 4)) {
- 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->len == 4 && ipcp_contains_option(ipcp, ipcp_len, IPCP_OPT_SECONDARY_DNS, 4)) {
- 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));
- }
-
- /* patch in length values */
- len_appended = msg->tail - start;
- *len1 = len_appended - 3;
- *len2 = len_appended - 3;
-
- offset += sizeof(pco_ipcp) + pco_ipcp->length;
- pco_ipcp = pco_contains_proto(&pdp->pco_req, offset, PCO_P_IPCP, sizeof(struct ipcp_hdr));
+ if (dns1->len == 4 && ipcp_contains_option(ipcp, ipcp_len, IPCP_OPT_PRIMARY_DNS, 4)) {
+ msgb_put_u8(resp, 0x81); /* DNS1 Tag */
+ msgb_put_u8(resp, 2 + dns1->len); /* DNS1 Length, incl. TL */
+ msgb_put_u32(resp, ntohl(dns1->v4.s_addr));
}
+ if (dns2->len == 4 && ipcp_contains_option(ipcp, ipcp_len, IPCP_OPT_SECONDARY_DNS, 4)) {
+ msgb_put_u8(resp, 0x83); /* DNS2 Tag */
+ msgb_put_u8(resp, 2 + dns2->len); /* DNS2 Length, incl. TL */
+ msgb_put_u32(resp, ntohl(dns2->v4.s_addr));
+ }
+
+ /* patch in length values */
+ len_appended = resp->tail - start;
+ *len1 = len_appended - 3;
+ *len2 = len_appended - 3;
+}
+
+static void process_pco_element_dns_ipv6(const struct pco_element *pco_elem, struct msgb *resp,
+ const struct apn_ctx *apn, struct pdp_t *pdp)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(apn->v6.cfg.dns); i++) {
+ const struct in46_addr *i46a = &apn->v6.cfg.dns[i];
+ if (i46a->len != 16)
+ continue;
+ msgb_t16lv_put(resp, PCO_P_DNS_IPv6_ADDR, i46a->len, i46a->v6.s6_addr);
+ }
+}
+
+static void process_pco_element_dns_ipv4(const struct pco_element *pco_elem, struct msgb *resp,
+ const struct apn_ctx *apn, struct pdp_t *pdp)
+{
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(apn->v4.cfg.dns); i++) {
+ const struct in46_addr *i46a = &apn->v4.cfg.dns[i];
+ if (i46a->len != 4)
+ continue;
+ msgb_t16lv_put(resp, PCO_P_DNS_IPv4_ADDR, i46a->len, (uint8_t *)&i46a->v4);
+ }
+}
+
+static void process_pco_element(const struct pco_element *pco_elem, struct msgb *resp,
+ const struct apn_ctx *apn, struct pdp_t *pdp)
+{
+ switch (ntohs(pco_elem->protocol_id)) {
+ case PCO_P_IPCP:
+ process_pco_element_ipcp(pco_elem, resp, apn, pdp);
+ break;
+ case PCO_P_DNS_IPv6_ADDR:
+ process_pco_element_dns_ipv6(pco_elem, resp, apn, pdp);
+ break;
+ case PCO_P_DNS_IPv4_ADDR:
+ process_pco_element_dns_ipv4(pco_elem, resp, apn, pdp);
+ break;
+ default:
+ break;
+ }
}
/* process one PCO request from a MS/UE, putting together the proper responses */
static void process_pco(const struct apn_ctx *apn, struct pdp_t *pdp)
{
- struct msgb *msg = msgb_alloc(256, "PCO");
- struct ippoolm_t *peer_v4 = pdp_get_peer_ipv(pdp, false);
- unsigned int i;
+ struct msgb *resp = msgb_alloc(256, "PCO.resp");
+ const struct ul255_t *pco = &pdp->pco_req;
+ const struct pco_element *pco_elem;
+ const uint8_t *cur;
- OSMO_ASSERT(msg);
- msgb_put_u8(msg, 0x80); /* ext-bit + configuration protocol byte */
+ /* build the header of the PCO response */
+ OSMO_ASSERT(resp);
+ msgb_put_u8(resp, 0x80); /* ext-bit + configuration protocol byte */
- if (peer_v4)
- build_ipcp_pco(apn, pdp, msg);
-
- if (pco_contains_proto(&pdp->pco_req, 0, PCO_P_DNS_IPv6_ADDR, 0)) {
- for (i = 0; i < ARRAY_SIZE(apn->v6.cfg.dns); i++) {
- const struct in46_addr *i46a = &apn->v6.cfg.dns[i];
- if (i46a->len != 16)
- continue;
- msgb_t16lv_put(msg, PCO_P_DNS_IPv6_ADDR, i46a->len, i46a->v6.s6_addr);
- }
+ /* iterate over the PCO elements in the request; call process_pco_element() for each */
+ for (cur = pco->v + 1, pco_elem = (const struct pco_element *) cur;
+ cur + sizeof(struct pco_element) <= pco->v + pco->l;
+ cur += pco_elem->length + sizeof(*pco_elem), pco_elem = (const struct pco_element *) cur) {
+ process_pco_element(pco_elem, resp, apn, pdp);
}
- if (pco_contains_proto(&pdp->pco_req, 0, PCO_P_DNS_IPv4_ADDR, 0)) {
- for (i = 0; i < ARRAY_SIZE(apn->v4.cfg.dns); i++) {
- const struct in46_addr *i46a = &apn->v4.cfg.dns[i];
- if (i46a->len != 4)
- continue;
- msgb_t16lv_put(msg, PCO_P_DNS_IPv4_ADDR, i46a->len, (uint8_t *)&i46a->v4);
- }
- }
-
- if (msgb_length(msg) > 1) {
- memcpy(pdp->pco_neg.v, msgb_data(msg), msgb_length(msg));
- pdp->pco_neg.l = msgb_length(msg);
+ /* copy the PCO response msgb and copy its contents over to the PDP context */
+ if (msgb_length(resp) > 1) {
+ memcpy(pdp->pco_neg.v, msgb_data(resp), msgb_length(resp));
+ pdp->pco_neg.l = msgb_length(resp);
} else
pdp->pco_neg.l = 0;
-
- msgb_free(msg);
+ msgb_free(resp);
}
+
static bool apn_supports_ipv4(const struct apn_ctx *apn)
{
if (apn->v4.cfg.static_prefix.addr.len || apn->v4.cfg.dynamic_prefix.addr.len)
--
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Gerrit-Project: osmo-ggsn
Gerrit-Branch: master
Gerrit-MessageType: newchange
Gerrit-Change-Id: I4a7d09279b6b259e2b95f1f51159b16838b2d94c
Gerrit-Change-Number: 13606
Gerrit-PatchSet: 1
Gerrit-Owner: Harald Welte <laforge at gnumonks.org>
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