From 779823c09cba151c3eb9043bc8ce28adb0dd737d Mon Sep 17 00:00:00 2001 From: Werner Koch Date: Fri, 16 Apr 2010 14:08:41 +0000 Subject: [PATCH] More robust detection of handle and sockets --- src/ChangeLog | 5 ++++ src/w32-io.c | 66 +++++++++++++++++++++++++++++++++++---------------- 2 files changed, 51 insertions(+), 20 deletions(-) diff --git a/src/ChangeLog b/src/ChangeLog index 7be7b5f..d4ef220 100644 --- a/src/ChangeLog +++ b/src/ChangeLog @@ -1,3 +1,8 @@ +2010-04-16 Werner Koch + + * w32-io.c (is_socket): New. + (reader, writer): Use it to figure out the API to use. + 2010-03-15 Werner Koch * gpgme.h.in: Add autoconf template to set generated file to diff --git a/src/w32-io.c b/src/w32-io.c index 762d617..d05db70 100644 --- a/src/w32-io.c +++ b/src/w32-io.c @@ -1,6 +1,6 @@ /* w32-io.c - W32 API I/O functions. Copyright (C) 2000 Werner Koch (dd9jn) - Copyright (C) 2001, 2002, 2003, 2004, 2007 g10 Code GmbH + Copyright (C) 2001, 2002, 2003, 2004, 2007, 2010 g10 Code GmbH This file is part of GPGME. @@ -175,16 +175,46 @@ set_synchronize (HANDLE hd) } +/* Return true if HD refers to a socket. */ +static int +is_socket (HANDLE hd) +{ + /* We need to figure out whether we are working on a socket or on a + handle. A trivial way would be to check for the return code of + recv and see if it is WSAENOTSOCK. However the recv may block + after the server process died and thus the destroy_reader will + hang. Another option is to use getsockopt to test whether it is + a socket. The bug here is that once a socket with a certain + values has been opened, closed and later a CreatePipe returned + the same value (i.e. handle), getsockopt still believes it is a + socket. What we do now is to use a combination of GetFileType + and GetNamedPipeInfo. The specs say that the latter may be used + on anonymous pipes as well. Note that there are claims that + since winsocket version 2 ReadFile may be used on a socket but + only if it is supported by the service provider. Tests on a + stock XP using a local TCP socket show that it does not work. */ + DWORD dummyflags, dummyoutsize, dummyinsize, dummyinst; + if (GetFileType (hd) == FILE_TYPE_PIPE + && !GetNamedPipeInfo (hd, &dummyflags, &dummyoutsize, + &dummyinsize, &dummyinst)) + return 1; /* Function failed; thus we assume it is a socket. */ + else + return 0; /* Success; this is not a socket. */ +} + + static DWORD CALLBACK reader (void *arg) { struct reader_context_s *ctx = arg; int nbytes; DWORD nread; - int try_recv = 1; + int sock; TRACE_BEG1 (DEBUG_SYSIO, "gpgme:reader", ctx->file_hd, "thread=%p", ctx->thread_hd); + sock = is_socket (ctx->file_hd); + for (;;) { LOCK (ctx->mutex); @@ -212,17 +242,15 @@ reader (void *arg) nbytes = READBUF_SIZE - ctx->writepos; UNLOCK (ctx->mutex); - TRACE_LOG1 ("reading %d bytes", nbytes); + TRACE_LOG2 ("%s %d bytes", sock? "receiving":"reading", nbytes); - if (try_recv) + if (sock) { int n; n = recv (handle_to_socket (ctx->file_hd), ctx->buffer + ctx->writepos, nbytes, 0); - if (n < 0 && WSAGetLastError () == WSAENOTSOCK) - try_recv = 0; - else if (n < 0) + if (n < 0) { ctx->error_code = (int) WSAGetLastError (); if (ctx->error_code == ERROR_BROKEN_PIPE) @@ -237,11 +265,9 @@ reader (void *arg) } break; } - else - nread = n; - + nread = n; } - if (!try_recv) + else { if (!ReadFile (ctx->file_hd, ctx->buffer + ctx->writepos, nbytes, &nread, NULL)) @@ -540,10 +566,12 @@ writer (void *arg) { struct writer_context_s *ctx = arg; DWORD nwritten; - int try_send = 1; + int sock; TRACE_BEG1 (DEBUG_SYSIO, "gpgme:writer", ctx->file_hd, "thread=%p", ctx->thread_hd); + sock = is_socket (ctx->file_hd); + for (;;) { LOCK (ctx->mutex); @@ -571,11 +599,12 @@ writer (void *arg) } UNLOCK (ctx->mutex); - TRACE_LOG1 ("writing %d bytes", ctx->nbytes); + TRACE_LOG2 ("%s %d bytes", sock?"sending":"writing", ctx->nbytes); + /* Note that CTX->nbytes is not zero at this point, because _gpgme_io_write always writes at least 1 byte before waking us up, unless CTX->stop_me is true, which we catch above. */ - if (try_send) + if (sock) { /* We need to try send first because a socket handle can't be used with WriteFile. */ @@ -583,19 +612,16 @@ writer (void *arg) n = send (handle_to_socket (ctx->file_hd), ctx->buffer, ctx->nbytes, 0); - if (n < 0 && WSAGetLastError () == WSAENOTSOCK) - try_send = 0; - else if (n < 0) + if (n < 0) { ctx->error_code = (int) WSAGetLastError (); ctx->error = 1; TRACE_LOG1 ("send error: ec=%d", ctx->error_code); break; } - else - nwritten = n; + nwritten = n; } - if (!try_send) + else { if (!WriteFile (ctx->file_hd, ctx->buffer, ctx->nbytes, &nwritten, NULL)) -- 2.26.2