gbproxy: Refactor IMSI matching
The current implementation makes it difficult to add further match
expressions.
This patch adds a new struct gbproxy_match that contains the fields
needed for each match expression. The matches (config) and the
results (link_info) are stored in arrays. All related functions are
updated to use them. The old fields in the config structure are
removed.
Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/gb_proxy_patch.c b/openbsc/src/gprs/gb_proxy_patch.c
index cf6eb88..5cac8a5 100644
--- a/openbsc/src/gprs/gb_proxy_patch.c
+++ b/openbsc/src/gprs/gb_proxy_patch.c
@@ -24,6 +24,7 @@
#include <openbsc/gprs_gb_parse.h>
#include <openbsc/gsm_04_08_gprs.h>
+#include <openbsc/gsm_data.h>
#include <openbsc/debug.h>
#include <osmocom/gprs/protocol/gsm_08_18.h>
@@ -198,6 +199,7 @@
struct gprs_llc_hdr_parsed *ghp = &parse_ctx->llc_hdr_parsed;
int have_patched = 0;
int fcs;
+ struct gbproxy_config *cfg = peer->cfg;
if (parse_ctx->ptmsi_enc && link_info &&
!parse_ctx->old_raid_is_foreign && peer->cfg->patch_ptmsi) {
@@ -216,7 +218,7 @@
}
}
- if (parse_ctx->new_ptmsi_enc && link_info && peer->cfg->patch_ptmsi) {
+ if (parse_ctx->new_ptmsi_enc && link_info && cfg->patch_ptmsi) {
uint32_t ptmsi;
if (parse_ctx->to_bss)
ptmsi = link_info->tlli.ptmsi;
@@ -243,9 +245,10 @@
}
if (parse_ctx->apn_ie &&
- peer->cfg->core_apn &&
+ cfg->core_apn &&
!parse_ctx->to_bss &&
- gbproxy_imsi_matches(peer, link_info) && peer->cfg->core_apn) {
+ gbproxy_imsi_matches(cfg, GBPROX_MATCH_PATCHING, link_info) &&
+ cfg->core_apn) {
size_t new_len;
gbproxy_patch_apn_ie(msg,
parse_ctx->apn_ie, parse_ctx->apn_ie_len,
@@ -371,35 +374,38 @@
err_info);
}
-void gbproxy_clear_patch_filter(struct gbproxy_config *cfg)
+void gbproxy_clear_patch_filter(struct gbproxy_match *match)
{
- if (cfg->check_imsi) {
- regfree(&cfg->imsi_re_comp);
- cfg->check_imsi = 0;
+ if (match->enable) {
+ regfree(&match->re_comp);
+ match->enable = 0;
}
+ talloc_free(match->re_str);
+ match->re_str = NULL;
}
-int gbproxy_set_patch_filter(struct gbproxy_config *cfg, const char *filter,
+int gbproxy_set_patch_filter(struct gbproxy_match *match, const char *filter,
const char **err_msg)
{
static char err_buf[300];
int rc;
- gbproxy_clear_patch_filter(cfg);
+ gbproxy_clear_patch_filter(match);
if (!filter)
return 0;
- rc = regcomp(&cfg->imsi_re_comp, filter,
+ rc = regcomp(&match->re_comp, filter,
REG_EXTENDED | REG_NOSUB | REG_ICASE);
if (rc == 0) {
- cfg->check_imsi = 1;
+ match->enable = 1;
+ match->re_str = talloc_strdup(tall_bsc_ctx, filter);
return 0;
}
if (err_msg) {
- regerror(rc, &cfg->imsi_re_comp,
+ regerror(rc, &match->re_comp,
err_buf, sizeof(err_buf));
*err_msg = err_buf;
}
@@ -407,13 +413,13 @@
return -1;
}
-int gbproxy_check_imsi(struct gbproxy_peer *peer,
+int gbproxy_check_imsi(struct gbproxy_match *match,
const uint8_t *imsi, size_t imsi_len)
{
char mi_buf[200];
int rc;
- if (!peer->cfg->check_imsi)
+ if (!match->enable)
return 1;
rc = gprs_is_mi_imsi(imsi, imsi_len);
@@ -427,11 +433,11 @@
LOGP(DGPRS, LOGL_DEBUG, "Checking IMSI '%s' (%d)\n", mi_buf, rc);
- rc = regexec(&peer->cfg->imsi_re_comp, mi_buf, 0, NULL, 0);
+ rc = regexec(&match->re_comp, mi_buf, 0, NULL, 0);
if (rc == REG_NOMATCH) {
LOGP(DGPRS, LOGL_INFO,
"IMSI '%s' doesn't match pattern '%s'\n",
- mi_buf, peer->cfg->match_re);
+ mi_buf, match->re_str);
return 0;
}