diff options
Diffstat (limited to 'src/htmsocket.c')
| -rw-r--r-- | src/htmsocket.c | 104 |
1 files changed, 83 insertions, 21 deletions
diff --git a/src/htmsocket.c b/src/htmsocket.c index 858a4c7..3abd7f6 100644 --- a/src/htmsocket.c +++ b/src/htmsocket.c @@ -103,9 +103,29 @@ typedef struct int id;
} desc;
+int IsAddressMulticast(unsigned long address)
+{
+ unsigned long adr = ntohl(address);
+ unsigned char A = (unsigned char)((adr & 0xFF000000) >> 24);
+ unsigned char B = (unsigned char)((adr & 0xFF0000) >> 16);
+ unsigned char C = (unsigned char)((adr & 0xFF00) >> 8);
+
+ if (A==224 && B==0 && C==0) {
+ // This multicast group range is reserved for routing
+ // information and not meant to be used by applications.
+ return -1;
+ }
+
+ // This is the multicast group IP range
+ if (A>=224 && A<=239)
+ return 1;
+
+ return 0;
+}
+
/* open a socket for HTM communication to given host on given portnumber */
/* if host is 0 then UNIX protocol is used (i.e. local communication */
-void *OpenHTMSocket(char *host, int portnumber, unsigned char multicast_TTL)
+void *OpenHTMSocket(char *host, int portnumber, short *multicast_TTL)
{
struct sockaddr_in cl_addr;
#ifndef WIN32
@@ -233,16 +253,37 @@ void *OpenHTMSocket(char *host, int portnumber, unsigned char multicast_TTL) perror("setsockopt broadcast");
}
- // set multicast Time-To-Live: ss
- if(setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL, &multicast_TTL, sizeof(multicast_TTL)) == -1) {
- perror("setsockopt TTL");
- }
-
- if(bind(sockfd, (struct sockaddr *) &cl_addr, sizeof(cl_addr)) < 0) {
- perror("could not bind\n");
- closesocket(sockfd);
- sockfd = -1;
- }
+ // check if specified address is a multicast group: ss 2007
+ int multicast = IsAddressMulticast(o->serv_addr.sin_addr.s_addr);
+
+ if (multicast == -1) {
+ perror("Multicast group range 224.0.0.[0-255] is reserved.\n");
+ *multicast_TTL = -2;
+ close(sockfd);
+ sockfd = -1;
+ }
+ else {
+ // set TTL according to whether we have a multicast group or not
+ if (multicast) {
+ if (*multicast_TTL<0)
+ *multicast_TTL = 1;
+ } else
+ *multicast_TTL = -1;
+
+ // set multicast Time-To-Live only if it is a multicast group: ss 2007
+ if(*multicast_TTL>=0) {
+ unsigned char ttl = (unsigned char)*multicast_TTL;
+ if (setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL,
+ &ttl, sizeof(ttl)) == -1)
+ perror("setsockopt TTL");
+ }
+
+ if(bind(sockfd, (struct sockaddr *) &cl_addr, sizeof(cl_addr)) < 0) {
+ perror("could not bind\n");
+ closesocket(sockfd);
+ sockfd = -1;
+ }
+ }
}
else { perror("unable to make socket\n");}
#else
@@ -259,16 +300,37 @@ void *OpenHTMSocket(char *host, int portnumber, unsigned char multicast_TTL) perror("setsockopt");
}
- // set multicast Time-To-Live: ss 2006
- if(setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL, &multicast_TTL, sizeof(multicast_TTL)) == -1) {
- perror("setsockopt TTL");
- }
-
- if(bind(sockfd, (struct sockaddr *) &cl_addr, sizeof(cl_addr)) < 0) {
- perror("could not bind\n");
- close(sockfd);
- sockfd = -1;
- }
+ // check if specified address is a multicast group: ss 2007
+ int multicast = IsAddressMulticast(o->serv_addr.sin_addr.s_addr);
+
+ if (multicast == -1) {
+ perror("Multicast group range 224.0.0.[0-255] is reserved.\n");
+ *multicast_TTL = -2;
+ close(sockfd);
+ sockfd = -1;
+ }
+ else {
+ // check if specified address is a multicast group: ss 2007
+ if (multicast) {
+ if (*multicast_TTL<0)
+ *multicast_TTL = 1;
+ } else
+ *multicast_TTL = -1;
+
+ // set multicast Time-To-Live only if it is a multicast group: ss 2007
+ if(*multicast_TTL>=0) {
+ unsigned char ttl = (unsigned char)*multicast_TTL;
+ if (setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL,
+ &ttl, sizeof(ttl)) == -1)
+ perror("setsockopt TTL");
+ }
+
+ if(bind(sockfd, (struct sockaddr *) &cl_addr, sizeof(cl_addr)) < 0) {
+ perror("could not bind\n");
+ close(sockfd);
+ sockfd = -1;
+ }
+ }
}
else { perror("unable to make socket\n");}
#endif
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