nat: Allow to have a regexp to match the MSISDN
The idea that MCC and MNC is enough to classify a subscriber
turns out to be wrong. Certain operatos license a number range
of IMSIs to others. When we see a '^' in the MCC field we treat
it as a regexp. The code now turns the MCC/MNC into a regexp
for the IMSI. It is not using extended POSIX regexp to match
the behavior of the access list.
diff --git a/openbsc/include/openbsc/bsc_nat.h b/openbsc/include/openbsc/bsc_nat.h
index c3f32eb..650d113 100644
--- a/openbsc/include/openbsc/bsc_nat.h
+++ b/openbsc/include/openbsc/bsc_nat.h
@@ -267,7 +267,7 @@
/* number rewriting */
char *num_rewr_name;
- struct osmo_config_list *num_rewr;
+ struct llist_head num_rewr;
/* USSD messages we want to match */
char *ussd_lst_name;
@@ -394,4 +394,18 @@
void bsc_nat_paging_group_add_lac(struct bsc_nat_paging_group *grp, int lac);
void bsc_nat_paging_group_del_lac(struct bsc_nat_paging_group *grp, int lac);
+/**
+ * Number rewriting support below
+ */
+struct bsc_nat_num_rewr_entry {
+ struct llist_head list;
+
+ regex_t msisdn_reg;
+ regex_t num_reg;
+
+ char *replace;
+};
+
+void bsc_nat_num_rewr_entry_adapt(struct bsc_nat *nat, const struct osmo_config_list *);
+
#endif
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c b/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c
index 76b56f6..a7b0044 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c
@@ -94,6 +94,7 @@
INIT_LLIST_HEAD(&nat->bsc_configs);
INIT_LLIST_HEAD(&nat->access_lists);
INIT_LLIST_HEAD(&nat->dests);
+ INIT_LLIST_HEAD(&nat->num_rewr);
nat->stats.sccp.conn = osmo_counter_alloc("nat.sccp.conn");
nat->stats.sccp.calls = osmo_counter_alloc("nat.sccp.calls");
@@ -801,10 +802,10 @@
static char *rewrite_non_international(struct bsc_nat *nat, void *ctx, const char *imsi,
struct gsm_mncc_number *called)
{
- struct osmo_config_entry *entry;
+ struct bsc_nat_num_rewr_entry *entry;
char *new_number = NULL;
- if (!nat->num_rewr)
+ if (llist_empty(&nat->num_rewr))
return NULL;
if (called->plan != 1)
@@ -813,36 +814,19 @@
return NULL;
/* need to find a replacement and then fix it */
- llist_for_each_entry(entry, &nat->num_rewr->entry, list) {
- regex_t reg;
+ llist_for_each_entry(entry, &nat->num_rewr, list) {
regmatch_t matches[2];
- if (entry->mcc[0] != '*' && strncmp(entry->mcc, imsi, 3) != 0)
+ /* check the IMSI match */
+ if (regexec(&entry->msisdn_reg, imsi, 0, NULL, 0) != 0)
continue;
- if (entry->mnc[0] != '*' && strncmp(entry->mnc, imsi + 3, 2) != 0)
- continue;
-
- if (entry->text[0] == '+') {
- LOGP(DNAT, LOGL_ERROR,
- "Plus is not allowed in the number");
- continue;
- }
-
- /* We have an entry for the IMSI. Need to match now */
- if (regcomp(®, entry->option, REG_EXTENDED) != 0) {
- LOGP(DNAT, LOGL_ERROR,
- "Regexp '%s' is not valid.\n", entry->option);
- continue;
- }
/* this regexp matches... */
- if (regexec(®, called->number, 2, matches, 0) == 0 &&
+ if (regexec(&entry->num_reg, called->number, 2, matches, 0) == 0 &&
matches[1].rm_eo != -1)
new_number = talloc_asprintf(ctx, "%s%s",
- entry->text,
+ entry->replace,
&called->number[matches[1].rm_so]);
- regfree(®);
-
if (new_number)
break;
}
@@ -973,3 +957,87 @@
return sccp;
}
+static void num_rewr_free_data(struct bsc_nat_num_rewr_entry *entry)
+{
+ regfree(&entry->msisdn_reg);
+ regfree(&entry->num_reg);
+ talloc_free(entry->replace);
+}
+
+void bsc_nat_num_rewr_entry_adapt(struct bsc_nat *nat, const struct osmo_config_list *list)
+{
+ struct bsc_nat_num_rewr_entry *entry, *tmp;
+ struct osmo_config_entry *cfg_entry;
+
+ /* free the old data */
+ llist_for_each_entry_safe(entry, tmp, &nat->num_rewr, list) {
+ num_rewr_free_data(entry);
+ llist_del(&entry->list);
+ talloc_free(entry);
+ }
+
+
+ if (!list)
+ return;
+
+ llist_for_each_entry(cfg_entry, &list->entry, list) {
+ char *regexp;
+ if (cfg_entry->text[0] == '+') {
+ LOGP(DNAT, LOGL_ERROR,
+ "Plus is not allowed in the number\n");
+ continue;
+ }
+
+ entry = talloc_zero(nat, struct bsc_nat_num_rewr_entry);
+ if (!entry) {
+ LOGP(DNAT, LOGL_ERROR,
+ "Allication of the num_rewr entry failed.\n");
+ continue;
+ }
+
+ entry->replace = talloc_strdup(entry, cfg_entry->text);
+ if (!entry->replace) {
+ LOGP(DNAT, LOGL_ERROR,
+ "Failed to copy the replacement text.\n");
+ talloc_free(entry);
+ continue;
+ }
+
+ /* we will now build a regexp string */
+ if (cfg_entry->mcc[0] == '^') {
+ regexp = talloc_strdup(entry, cfg_entry->mcc);
+ } else {
+ regexp = talloc_asprintf(entry, "^%s%s",
+ cfg_entry->mcc[0] == '*' ?
+ "[0-9][0-9][0-9]" : cfg_entry->mcc,
+ cfg_entry->mnc[0] == '*' ?
+ "[0-9][0-9]" : cfg_entry->mnc);
+ }
+
+ if (!regexp) {
+ LOGP(DNAT, LOGL_ERROR, "Failed to create a regexp string.\n");
+ talloc_free(entry);
+ continue;
+ }
+
+ if (regcomp(&entry->msisdn_reg, regexp, 0) != 0) {
+ LOGP(DNAT, LOGL_ERROR,
+ "Failed to compile regexp '%s'\n", regexp);
+ talloc_free(regexp);
+ talloc_free(entry);
+ continue;
+ }
+
+ talloc_free(regexp);
+ if (regcomp(&entry->num_reg, cfg_entry->option, REG_EXTENDED) != 0) {
+ LOGP(DNAT, LOGL_ERROR,
+ "Failed to compile regexp '%s\n'", cfg_entry->option);
+ regfree(&entry->msisdn_reg);
+ talloc_free(entry);
+ continue;
+ }
+
+ /* we have copied the number */
+ llist_add_tail(&entry->list, &nat->num_rewr);
+ }
+}
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c b/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
index 0375cf8..38b5a09 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
@@ -461,16 +461,16 @@
"number-rewrite FILENAME",
"Set the file with rewriting rules.\n" "Filename")
{
+ struct osmo_config_list *rewr = NULL;
+
bsc_replace_string(_nat, &_nat->num_rewr_name, argv[0]);
if (_nat->num_rewr_name) {
- if (_nat->num_rewr)
- talloc_free(_nat->num_rewr);
- _nat->num_rewr = osmo_config_list_parse(_nat, _nat->num_rewr_name);
- return _nat->num_rewr == NULL ? CMD_WARNING : CMD_SUCCESS;
+ rewr = osmo_config_list_parse(_nat, _nat->num_rewr_name);
+ bsc_nat_num_rewr_entry_adapt(_nat, rewr);
+ talloc_free(rewr);
+ return CMD_SUCCESS;
} else {
- if (_nat->num_rewr)
- talloc_free(_nat->num_rewr);
- _nat->num_rewr = NULL;
+ bsc_nat_num_rewr_entry_adapt(_nat, NULL);
return CMD_SUCCESS;
}
}
diff --git a/openbsc/tests/bsc-nat/bsc_nat_test.c b/openbsc/tests/bsc-nat/bsc_nat_test.c
index 1645f70..32f4f72 100644
--- a/openbsc/tests/bsc-nat/bsc_nat_test.c
+++ b/openbsc/tests/bsc-nat/bsc_nat_test.c
@@ -854,7 +854,7 @@
entry.option = "^0([1-9])";
entry.text = "0049";
llist_add_tail(&entry.list, &entries.entry);
- nat->num_rewr = &entries;
+ bsc_nat_num_rewr_entry_adapt(nat, &entries);
/* verify that nothing changed */
msgb_reset(msg);
@@ -917,6 +917,7 @@
/* Make sure that a wildcard is matching */
entry.mnc = "*";
+ bsc_nat_num_rewr_entry_adapt(nat, &entries);
msg = msgb_alloc(4096, "test_dt_filter");
copy_to_msg(msg, cc_setup_national, ARRAY_SIZE(cc_setup_national));
parsed = bsc_nat_parse(msg);
@@ -951,6 +952,7 @@
/* Make sure that a wildcard is matching */
entry.mnc = "09";
+ bsc_nat_num_rewr_entry_adapt(nat, &entries);
msg = msgb_alloc(4096, "test_dt_filter");
copy_to_msg(msg, cc_setup_national, ARRAY_SIZE(cc_setup_national));
parsed = bsc_nat_parse(msg);