gsm: Verify the MNCC_VERSION of the BSC/MS and close the socket on mismatch

The BSC/MS will send a Hello packet that includes the version number,
make LCR verify this version number and close the socket in case it
does not match a supported version.

diff --git a/gsm.cpp b/gsm.cpp
index e6806c3..227d618 100644 (file)
--- a/gsm.cpp
+++ b/gsm.cpp
@@ -1042,6 +1042,7 @@ static int mncc_fd_read(struct lcr_fd *lfd, void *inst, int idx)
        int rc;
        static char buf[sizeof(struct gsm_mncc)+1024];
        struct gsm_mncc *mncc_prim = (struct gsm_mncc *) buf;
+       struct gsm_mncc_hello *hello = (struct gsm_mncc_hello *) buf;
 
        memset(buf, 0, sizeof(buf));
        rc = recv(lfd->fd, buf, sizeof(buf), 0);
@@ -1050,6 +1051,17 @@ static int mncc_fd_read(struct lcr_fd *lfd, void *inst, int idx)
        if (rc < 0)
                return rc;
 
+       /* TODO: size check? */
+       switch (mncc_prim->msg_type) {
+       case MNCC_SOCKET_HELLO:
+               if (hello->version != MNCC_SOCK_VERSION) {
+                       PERROR("MNCC version different. BSC version is %u\n", hello->version);
+                       mncc_fd_close(lcr_gsm, lfd);
+                       return 0;
+               }
+               break;
+       }
+
        /* Hand the MNCC message into LCR */
        switch (lcr_gsm->type) {
 #ifdef WITH_GSM_BS

diff --git a/mncc.h b/mncc.h
index e5f8216..fac7145 100644 (file)
--- a/mncc.h
+++ b/mncc.h
@@ -56,6 +56,8 @@
 #define GSM_TCHF_FRAME         0x0300
 #define GSM_TCHF_FRAME_EFR     0x0301
 
+#define MNCC_SOCKET_HELLO      0x0400
+
 #define GSM_MAX_FACILITY       128
 #define GSM_MAX_SSVERSION      128
 #define GSM_MAX_USERUSER       128
@@ -185,3 +187,8 @@ struct gsm_data_frame {
        unsigned char   data[0];
 };
 
+#define MNCC_SOCK_VERSION      1
+struct gsm_mncc_hello {
+       u_int32_t       msg_type;
+       u_int32_t       version;
+};