diff options
Diffstat (limited to 'unix/tclUnixSock.c')
| -rw-r--r-- | unix/tclUnixSock.c | 39 |
1 files changed, 38 insertions, 1 deletions
diff --git a/unix/tclUnixSock.c b/unix/tclUnixSock.c index 8167077..f7bd0be 100644 --- a/unix/tclUnixSock.c +++ b/unix/tclUnixSock.c @@ -1429,7 +1429,7 @@ Tcl_OpenTcpServer( * clients. */ ClientData acceptProcData) /* Data for the callback. */ { - int status = 0, sock = -1, reuseaddr = 1, chosenport = 0; + int status = 0, sock = -1, reuseaddr = 1, chosenport; struct addrinfo *addrlist = NULL, *addrPtr; /* socket address */ TcpState *statePtr = NULL; char channelName[SOCK_CHAN_LENGTH]; @@ -1444,6 +1444,37 @@ Tcl_OpenTcpServer( enum { LOOKUP, SOCKET, BIND, LISTEN } howfar = LOOKUP; int my_errno = 0; + /* + * If we were called with port 0 to listen on a random port number, we + * copy the port number from the first member of the addrinfo list to all + * subsequent members, so that IPv4 and IPv6 listen on the same port. This + * might fail to bind() with EADDRINUSE if a port is free on the first + * address family in the list but already used on the other. In this case + * we revert everything we've done so far and start from scratch hoping + * that next time we'll find a port number that is usable on all address + * families. We try this at most MAXRETRY times to avoid an endless loop + * if all ports are taken. + */ + int retry = 0; +#define MAXRETRY 10 + + repeat: + if (retry > 0) { + if (statePtr != NULL) { + TcpCloseProc(statePtr, NULL); + statePtr = NULL; + } + if (addrlist != NULL) { + freeaddrinfo(addrlist); + addrlist = NULL; + } + if (retry >= MAXRETRY) { + goto error; + } + } + retry++; + chosenport = 0; + if (!TclCreateSocketAddress(interp, &addrlist, myHost, port, 1, &errorMsg)) { my_errno = errno; goto error; @@ -1512,6 +1543,9 @@ Tcl_OpenTcpServer( } close(sock); sock = -1; + if (port == 0 && errno == EADDRINUSE) { + goto repeat; + } continue; } if (port == 0 && chosenport == 0) { @@ -1535,6 +1569,9 @@ Tcl_OpenTcpServer( } close(sock); sock = -1; + if (port == 0 && errno == EADDRINUSE) { + goto repeat; + } continue; } if (statePtr == NULL) { |