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Modified mechanism to assign privileged ports and enable it for Windo…

…ws as well
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1 parent 6733694 commit 2521374f70d1a666c0e8d59eec926ef254ffc186 @warped-rudi warped-rudi committed with Jun 14, 2012
Showing with 29 additions and 25 deletions.
  1. +29 −25 lib/socket.c
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@@ -362,8 +362,6 @@ static int rpc_connect_sockaddr_async(struct rpc_context *rpc, struct sockaddr_s
return -1;
}
-
-#if !defined(WIN32)
/* Some systems allow you to set capabilities on an executable
* to allow the file to be executed with privilege to bind to
* privileged system ports, even if the user is not root.
@@ -378,32 +376,38 @@ static int rpc_connect_sockaddr_async(struct rpc_context *rpc, struct sockaddr_s
* On linux, use
* sudo setcap 'cap_net_bind_service=+ep' /path/executable
* to make the executable able to bind to a system port.
+ *
+ * On Windows, there is no concept of privileged ports. Thus
+ * binding will usually succeed.
*/
- if (1) {
- static int port = 200;
- int i;
- int one = 1;
-
- setsockopt(rpc->fd, SOL_SOCKET, SO_REUSEADDR, (char *)&one, sizeof(one));
-
- for (i = 0; i < 500; i++) {
- struct sockaddr_in sin;
-
- if(++port > 700) port = 200;
-
- memset(&sin, 0, sizeof(sin));
- sin.sin_port = htons(port);
- sin.sin_family = AF_INET;
- sin.sin_addr.s_addr = 0;
-
- if (bind(rpc->fd, (struct sockaddr *)&sin, sizeof(struct sockaddr_in)) != 0 && errno != EACCES) {
- /* we didnt get EACCES, so try again */
- continue;
+ {
+ struct sockaddr_in sin;
+ static int portOfs = 0;
+ const int firstPort = 512; /* >= 512 according to Sun docs */
+ const int portCount = IPPORT_RESERVED - firstPort;
+ int startOfs = portOfs, port, rc;
+
+ do {
+ rc = -1;
+ port = htons(firstPort + portOfs);
+ portOfs = (portOfs + 1) % portCount;
+
+ /* skip well-known ports */
+ if (!getservbyport(port, "tcp")) {
+ memset(&sin, 0, sizeof(sin));
+ sin.sin_port = port;
+ sin.sin_family = AF_INET;
+ sin.sin_addr.s_addr = 0;
+
+ rc = bind(rpc->fd, (struct sockaddr *)&sin, sizeof(struct sockaddr_in));
+#if !defined(WIN32)
+ /* we got EACCES, so don't try again */
+ if (rc != 0 && errno == EACCES)
+ break;
+#endif
}
- break;
- }
+ } while (rc != 0 && portOfs != startOfs);
}
-#endif
set_nonblocking(rpc->fd);

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