[PATCH] osmo-bsc[master]: Check and handle SMS encoding failure

[Max]

Review at  https://gerrit.osmocom.org/5615

Check and handle SMS encoding failure

The SMS address encoding can fail due to gsm48_encode_bcd_number() which
was not checked for because wrong type was used. Fix this by using
correct type, checking for error and propagating it to the caller.

Change-Id: I9fc16e24f7df5ebad6f4f1b389b2c5e861be95d7
Fixes: CID57882
---
M src/osmo-bsc_nat/bsc_nat_rewrite.c
1 file changed, 22 insertions(+), 8 deletions(-)


  git pull ssh://gerrit.osmocom.org:29418/osmo-bsc refs/changes/15/5615/1

diff --git a/src/osmo-bsc_nat/bsc_nat_rewrite.c 
b/src/osmo-bsc_nat/bsc_nat_rewrite.c
index 75ed4ec..7db9234 100644
--- a/src/osmo-bsc_nat/bsc_nat_rewrite.c
+++ b/src/osmo-bsc_nat/bsc_nat_rewrite.c
@@ -340,10 +340,10 @@
 /**
  * This is a helper for GSM 04.11 8.2.5.2 Destination address element
  */
-void sms_encode_addr_element(struct msgb *out, const char *new_number,
+static bool sms_encode_addr_element(struct msgb *out, const char *new_number,
                             int format, int tp_data)
 {
-       uint8_t new_addr_len;
+       int new_addr_len;
        uint8_t new_addr[26];
 
        /*
@@ -355,6 +355,9 @@
         */
        new_addr_len = gsm48_encode_bcd_number(new_addr, ARRAY_SIZE(new_addr),
                                               1, new_number);
+       if (new_addr_len < 0)
+               return false;
+
        new_addr[1] = format;
        if (tp_data) {
                uint8_t *data = msgb_put(out, new_addr_len);
@@ -363,6 +366,8 @@
        } else {
                msgb_lv_put(out, new_addr_len - 1, new_addr + 1);
        }
+
+       return true;
 }
 
 static struct msgb *sms_create_new(uint8_t type, uint8_t ref,
@@ -391,7 +396,10 @@
        msgb_v_put(out, ref);
        msgb_lv_put(out, orig_addr_len, orig_addr_ptr);
 
-       sms_encode_addr_element(out, new_number, 0x91, 0);
+       if (!sms_encode_addr_element(out, new_number, 0x91, 0)) {
+               LOGP(DNAT, LOGL_ERROR, "Failed to encode SMS address.\n");
+               return NULL;
+       }
 
 
        /* Patch the TPDU from here on */
@@ -411,11 +419,17 @@
                msgb_v_put(out, data_ptr[1]);
 
                /* encode the new number and put it */
-               if (strncmp(new_dest_nr, "00", 2) == 0)
-                       sms_encode_addr_element(out, new_dest_nr + 2, 0x91, 1);
-               else
-                       sms_encode_addr_element(out, new_dest_nr, 0x81, 1);
-
+               if (strncmp(new_dest_nr, "00", 2) == 0) {
+                       if (!sms_encode_addr_element(out, new_dest_nr + 2, 
0x91, 1)) {
+                               LOGP(DNAT, LOGL_ERROR, "Failed to encode SMS 
address.\n");
+                               return NULL;
+                       }
+               } else {
+                       if (!sms_encode_addr_element(out, new_dest_nr, 0x81, 
1)) {
+                               LOGP(DNAT, LOGL_ERROR, "Failed to encode SMS 
address.\n");
+                               return NULL;
+                       }
+               }
                /* Copy the rest after the TP-DS */
                data = msgb_put(out, data_len - 2 - 1 - old_dest_len);
                memcpy(data, &data_ptr[2 + 1 + old_dest_len], data_len - 2 - 1 
- old_dest_len);

-- 
To view, visit https://gerrit.osmocom.org/5615
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Gerrit-MessageType: newchange
Gerrit-Change-Id: I9fc16e24f7df5ebad6f4f1b389b2c5e861be95d7
Gerrit-PatchSet: 1
Gerrit-Project: osmo-bsc
Gerrit-Branch: master
Gerrit-Owner: Max <msur...@sysmocom.de>