diff options
Diffstat (limited to 'ggsn/ggsn.c')
| -rw-r--r-- | ggsn/ggsn.c | 87 |
1 files changed, 86 insertions, 1 deletions
diff --git a/ggsn/ggsn.c b/ggsn/ggsn.c index c559923..e95471a 100644 --- a/ggsn/ggsn.c +++ b/ggsn/ggsn.c @@ -1,7 +1,7 @@ /* * OsmoGGSN - Gateway GPRS Support Node * Copyright (C) 2002, 2003, 2004 Mondru AB. - * Copyright (C) 2017 by Harald Welte <laforge@gnumonks.org> + * Copyright (C) 2017-2019 by Harald Welte <laforge@gnumonks.org> * * The contents of this file may be used under the terms of the GNU * General Public License Version 2, provided that the above copyright @@ -47,6 +47,7 @@ #include <osmocom/core/stats.h> #include <osmocom/core/rate_ctr.h> #include <osmocom/core/timer.h> +#include <osmocom/core/utils.h> #include <osmocom/ctrl/control_if.h> #include <osmocom/ctrl/control_cmd.h> #include <osmocom/ctrl/control_vty.h> @@ -499,6 +500,87 @@ static struct ippoolm_t *pdp_get_peer_ipv(struct pdp_t *pdp, bool is_ipv6) { return NULL; } +/* RFC 1334, section 3.2. Packet Format */ +struct pap_element { + uint8_t code; + uint8_t id; + uint16_t len; /* length including header */ + uint8_t data[0]; +} __attribute__((packed)); + +enum pap_code { + PAP_CODE_AUTH_REQ = 1, + PAP_CODE_AUTH_ACK = 2, + PAP_CODE_AUTH_NAK = 3, +}; + +static const char *pap_welcome = "Welcome to OsmoGGSN " PACKAGE_VERSION; + +/* Handle PAP protocol according to RFC 1334 */ +static void process_pco_element_pap(const struct pco_element *pco_in, struct msgb *resp, + const struct apn_ctx *apn, struct pdp_t *pdp) +{ + const struct pap_element *pap_in = (const struct pap_element *) pco_in->data; + uint16_t pap_in_len; + uint8_t peer_id_len; + const uint8_t *peer_id; + unsigned int pap_welcome_len; + uint8_t pap_out_size; + struct pap_element *pap_out; + + if (pco_in->length < sizeof(struct pap_element)) + goto ret_broken; + + pap_in_len = osmo_load16be(&pap_in->len); + if (pco_in->length < pap_in_len) + goto ret_broken; + /* "pco_in->length > pap_in_len" is allowed: RFC1334 2.2 states: + "Octets outside the range of the Length field should be treated as + Data Link Layer padding and should be ignored on reception." + */ + + switch (pap_in->code) { + case PAP_CODE_AUTH_REQ: + if (pap_in_len < sizeof(struct pap_element) + 1) + goto ret_broken_auth; + peer_id_len = pap_in->data[0]; + if (pap_in_len < sizeof(struct pap_element) + 1 + peer_id_len) + goto ret_broken_auth; + peer_id = &pap_in->data[1]; + LOGPPDP(LOGL_DEBUG, pdp, "PCO PAP PeerId = %s, ACKing\n", + osmo_quote_str((const char *)peer_id, peer_id_len)); + /* Password-Length + Password following here, but we don't care */ + + /* Prepare response, we ACK all of them: */ + pap_welcome_len = strlen(pap_welcome); + /* +1: Length field of pap_welcome Message */ + pap_out_size = sizeof(struct pap_element) + 1 + pap_welcome_len; + pap_out = alloca(pap_out_size); + pap_out->code = PAP_CODE_AUTH_ACK; + pap_out->id = pap_in->id; + pap_out->len = htons(pap_out_size); + pap_out->data[0] = pap_welcome_len; + memcpy(pap_out->data+1, pap_welcome, pap_welcome_len); + msgb_t16lv_put(resp, PCO_P_PAP, pap_out_size, (uint8_t *) pap_out); + break; + case PAP_CODE_AUTH_ACK: + case PAP_CODE_AUTH_NAK: + default: + LOGPPDP(LOGL_NOTICE, pdp, "Unsupported PAP PCO Code %u, ignoring\n", pap_in->code); + break; + } + return; + +ret_broken_auth: + LOGPPDP(LOGL_NOTICE, pdp, "Invalid PAP AuthenticateReq: %s, ignoring\n", + osmo_hexdump_nospc((const uint8_t *)pco_in, pco_in->length)); + return; + +ret_broken: + LOGPPDP(LOGL_NOTICE, pdp, "Invalid PAP PCO Length: %s, ignoring\n", + osmo_hexdump_nospc((const uint8_t *)pco_in, pco_in->length)); +} + static void process_pco_element_ipcp(const struct pco_element *pco_elem, struct msgb *resp, const struct apn_ctx *apn, struct pdp_t *pdp) { @@ -580,6 +662,9 @@ static void process_pco_element(const struct pco_element *pco_elem, struct msgb const struct apn_ctx *apn, struct pdp_t *pdp) { switch (ntohs(pco_elem->protocol_id)) { + case PCO_P_PAP: + process_pco_element_pap(pco_elem, resp, apn, pdp); + break; case PCO_P_IPCP: process_pco_element_ipcp(pco_elem, resp, apn, pdp); break; |