sgsn: Add functions to handle APN contexts
This commit adds the exported functions apn_ctx_find_alloc,
apn_ctx_free, apn_ctx_by_name, and apn_ctx_match to manage and
retrieve APN to GGSN mappings.
The following VTY commands are added to 'config-sgsn':
- apn APN ggsn <0-255>
- apn APN imsi-prefix PREFIX ggsn <0-255>
which maps an APN gateway string to an SGSN id. The SGSN must be
configured in advance. When matching an APN string, entries with a
leading '*' are used for suffix matching, otherwise an exact match is
done. When a prefix is given, it is matched against the IMSI. If
several entries match, a longer matching IMSI prefix has precedence.
If there are several matching entries with the same PREFIX, the entry
with longest matching APN is returned.
Ticket: OW#1334
Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/gprs_sgsn.c b/openbsc/src/gprs/gprs_sgsn.c
index 555be57..54fe15c 100644
--- a/openbsc/src/gprs/gprs_sgsn.c
+++ b/openbsc/src/gprs/gprs_sgsn.c
@@ -387,41 +387,100 @@
/* APN contexts */
-#if 0
-struct apn_ctx *apn_ctx_alloc(const char *ap_name)
+static struct apn_ctx *sgsn_apn_ctx_alloc(const char *ap_name, const char *imsi_prefix)
{
struct apn_ctx *actx;
- actx = talloc_zero(talloc_bsc_ctx, struct apn_ctx);
+ actx = talloc_zero(tall_bsc_ctx, struct apn_ctx);
if (!actx)
return NULL;
actx->name = talloc_strdup(actx, ap_name);
+ actx->imsi_prefix = talloc_strdup(actx, imsi_prefix);
+
+ llist_add_tail(&actx->list, &sgsn_apn_ctxts);
return actx;
}
-struct apn_ctx *apn_ctx_by_name(const char *name)
+void sgsn_apn_ctx_free(struct apn_ctx *actx)
+{
+ llist_del(&actx->list);
+ talloc_free(actx);
+}
+
+struct apn_ctx *sgsn_apn_ctx_match(const char *name, const char *imsi)
+{
+ struct apn_ctx *actx;
+ struct apn_ctx *found_actx = NULL;
+ size_t imsi_prio = 0;
+ size_t name_prio = 0;
+ size_t name_req_len = strlen(name);
+
+ llist_for_each_entry(actx, &sgsn_apn_ctxts, list) {
+ size_t name_ref_len, imsi_ref_len;
+ const char *name_ref_start, *name_match_start;
+
+ imsi_ref_len = strlen(actx->imsi_prefix);
+ if (strncmp(actx->imsi_prefix, imsi, imsi_ref_len) != 0)
+ continue;
+
+ if (imsi_ref_len < imsi_prio)
+ continue;
+
+ /* IMSI matches */
+
+ name_ref_start = &actx->name[0];
+ if (name_ref_start[0] == '*') {
+ /* Suffix match */
+ name_ref_start += 1;
+ name_ref_len = strlen(name_ref_start);
+ if (name_ref_len > name_req_len)
+ continue;
+ } else {
+ name_ref_len = strlen(name_ref_start);
+ if (name_ref_len != name_req_len)
+ continue;
+ }
+
+ name_match_start = name + (name_req_len - name_ref_len);
+ if (strcasecmp(name_match_start, name_ref_start) != 0)
+ continue;
+
+ /* IMSI and name match */
+
+ if (imsi_ref_len == imsi_prio && name_ref_len < name_prio)
+ /* Lower priority, skip */
+ continue;
+
+ imsi_prio = imsi_ref_len;
+ name_prio = name_ref_len;
+ found_actx = actx;
+ }
+ return found_actx;
+}
+
+struct apn_ctx *sgsn_apn_ctx_by_name(const char *name, const char *imsi_prefix)
{
struct apn_ctx *actx;
llist_for_each_entry(actx, &sgsn_apn_ctxts, list) {
- if (!strcmp(name, actx->name))
+ if (strcasecmp(name, actx->name) == 0 &&
+ strcasecmp(imsi_prefix, actx->imsi_prefix) == 0)
return actx;
}
return NULL;
}
-struct apn_ctx *apn_ctx_find_alloc(const char *name)
+struct apn_ctx *sgsn_apn_ctx_find_alloc(const char *name, const char *imsi_prefix)
{
struct apn_ctx *actx;
- actx = apn_ctx_by_name(name);
+ actx = sgsn_apn_ctx_by_name(name, imsi_prefix);
if (!actx)
- actx = apn_ctx_alloc(name);
+ actx = sgsn_apn_ctx_alloc(name, imsi_prefix);
return actx;
}
-#endif
uint32_t sgsn_alloc_ptmsi(void)
{
diff --git a/openbsc/src/gprs/sgsn_vty.c b/openbsc/src/gprs/sgsn_vty.c
index 81b9d7f..d85ea01 100644
--- a/openbsc/src/gprs/sgsn_vty.c
+++ b/openbsc/src/gprs/sgsn_vty.c
@@ -126,6 +126,7 @@
{
struct sgsn_ggsn_ctx *gctx;
struct imsi_acl_entry *acl;
+ struct apn_ctx *actx;
vty_out(vty, "sgsn%s", VTY_NEWLINE);
@@ -151,6 +152,18 @@
llist_for_each_entry(acl, &g_cfg->imsi_acl, list)
vty_out(vty, " imsi-acl add %s%s", acl->imsi, VTY_NEWLINE);
+ if (llist_empty(&sgsn_apn_ctxts))
+ vty_out(vty, " ! apn * ggsn 0%s", VTY_NEWLINE);
+ llist_for_each_entry(actx, &sgsn_apn_ctxts, list) {
+ if (strlen(actx->imsi_prefix) > 0)
+ vty_out(vty, " apn %s imsi-prefix %s ggsn %d%s",
+ actx->name, actx->imsi_prefix, actx->ggsn->id,
+ VTY_NEWLINE);
+ else
+ vty_out(vty, " apn %s ggsn %d%s", actx->name,
+ actx->ggsn->id, VTY_NEWLINE);
+ }
+
return CMD_SUCCESS;
}
@@ -216,14 +229,55 @@
return CMD_SUCCESS;
}
-#if 0
+#define APN_STR "Configure the information per APN\n"
+#define APN_GW_STR "The APN gateway name optionally prefixed by '*' (wildcard)\n"
+
+static int add_apn_ggsn_mapping(struct vty *vty, const char *apn_str,
+ const char *imsi_prefix, int ggsn_id)
+{
+ struct apn_ctx *actx;
+ struct sgsn_ggsn_ctx *ggsn;
+
+ ggsn = sgsn_ggsn_ctx_by_id(ggsn_id);
+ if (ggsn == NULL) {
+ vty_out(vty, "%% a GGSN with id %d has not been defined%s",
+ ggsn_id, VTY_NEWLINE);
+ return CMD_WARNING;
+ }
+
+ actx = sgsn_apn_ctx_find_alloc(apn_str, imsi_prefix);
+ if (!actx) {
+ vty_out(vty, "%% unable to create APN context for %s/%s%s",
+ apn_str, imsi_prefix, VTY_NEWLINE);
+ return CMD_WARNING;
+ }
+
+ actx->ggsn = ggsn;
+
+ return CMD_SUCCESS;
+}
+
DEFUN(cfg_apn_ggsn, cfg_apn_ggsn_cmd,
"apn APNAME ggsn <0-255>",
- "")
+ APN_STR APN_GW_STR
+ "Select the GGSN to use when the APN gateway prefix matches\n"
+ "The GGSN id")
{
- struct apn_ctx **
+
+ return add_apn_ggsn_mapping(vty, argv[0], "", atoi(argv[1]));
}
-#endif
+
+DEFUN(cfg_apn_imsi_ggsn, cfg_apn_imsi_ggsn_cmd,
+ "apn APNAME imsi-prefix IMSIPRE ggsn <0-255>",
+ APN_STR APN_GW_STR
+ "Restrict rule to a certain IMSI prefix\n"
+ "An IMSI prefix\n"
+ "Select the GGSN to use when APN gateway and IMSI prefix match\n"
+ "The GGSN id")
+{
+
+ return add_apn_ggsn_mapping(vty, argv[0], argv[1], atoi(argv[2]));
+}
const struct value_string gprs_mm_st_strs[] = {
{ GMM_DEREGISTERED, "DEREGISTERED" },
@@ -757,6 +811,8 @@
install_element(SGSN_NODE, &cfg_auth_policy_cmd);
install_element(SGSN_NODE, &cfg_gsup_remote_ip_cmd);
install_element(SGSN_NODE, &cfg_gsup_remote_port_cmd);
+ install_element(SGSN_NODE, &cfg_apn_ggsn_cmd);
+ install_element(SGSN_NODE, &cfg_apn_imsi_ggsn_cmd);
return 0;
}