diff options
Diffstat (limited to 'socket.c')
| -rw-r--r-- | socket.c | 37 |
1 files changed, 29 insertions, 8 deletions
@@ -163,7 +163,7 @@ int SockOpen(const char *host, const char *service, const char *options, } if (connect(i, (struct sockaddr *) ai->ai_addr, ai->ai_addrlen) < 0) { freeaddrinfo(ai); - close(i); + SockClose(i); return -1; } #endif @@ -226,7 +226,7 @@ int SockOpen(const char *host, int clientPort, const char *options, if (connect(sock, (struct sockaddr *) &ad, sizeof(ad)) < 0) { int olderr = errno; - close(sock); + SockClose(sock); h_errno = 0; errno = olderr; return -1; @@ -272,14 +272,14 @@ int SockOpen(const char *host, int clientPort, const char *options, memcpy(&ad.sin_addr, *pptr, sizeof(struct in_addr)); if (connect(sock, (struct sockaddr *) &ad, sizeof(ad)) == 0) break; /* success */ - close(sock); + SockClose(sock); memset(&ad, 0, sizeof(ad)); ad.sin_family = AF_INET; } if(*pptr == NULL) { int olderr = errno; - close(sock); + SockClose(sock); h_errno = 0; errno = olderr; return -1; @@ -651,8 +651,9 @@ int SSLOpen(int sock, char *mycert, char *mykey, char *servercname ) #endif int SockClose(int sock) -/* close a socket (someday we may do other cleanup here) */ +/* close a socket gracefully */ { + char ch; #ifdef SSL_ENABLE SSL *ssl; @@ -662,15 +663,35 @@ int SockClose(int sock) _ssl_context[sock] = NULL; } #endif - return(close(sock)); + + /* Half-close the connection first so the other end gets notified. + * + * This stops sends but allows receives (effectively, it sends a + * TCP <FIN>). We ignore the return from this function because + * some older BSD-based implementations fail shutdown() if a TCP + * reset has been recieved. In any case, if it fails it means the + * connection is already closed anyway, so it doesn't matter. + */ + shutdown(sock, 1); + + /* If there is any data still waiting in the queue, discard it. + * Call recv() until either it returns 0 (meaning we received a FIN) + * or any error occurs. This makes sure all data sent by the other + * side is acknowledged at the TCP level. + */ + if (recv(sock, &ch, 1, MSG_PEEK) > 0) + while (recv(sock, &ch, 1, MSG_NOSIGNAL) > 0) + continue; + + /* if there's an error closing at this point, not much we can do */ + return(close(sock)); /* this is guarded */ } #ifdef MAIN /* * Use the chargen service to test input buffering directly. * You may have to uncomment the `chargen' service description in your - * inetd.conf (and then SIGHUP inetd) for this to work. - */ + * inetd.conf (and then SIGHUP inetd) for this to work. */ main() { int sock = SockOpen("localhost", 19, NULL); |