From 54800aa975418fe3570f3206a5f9b277dc59bd47 Mon Sep 17 00:00:00 2001 From: Lev Stipakov Date: Tue, 3 May 2022 03:28:40 +0300 Subject: [PATCH] Fix M_ERRNO behavior on Windows We use M_ERRNO flag in logging to display error code and error message. This has been broken on Windows, where we use error code from GetLastError() and error description from strerror(). strerror() expects C runtime error code, which is quite different from last error code from WinAPI call. As a result, we got incorrect error description. The ultimate fix would be introducing another flag for WinAPI errors, like M_WINERR and use either that or M_ERRNO depends on context. However, the change would be quite intrusive and in some cases it is hard to say which one to use without looking into internals. Instead we stick to M_ERRNO and in Windows case we first try to obtain error code from GetLastError() and if it returns ERROR_SUCCESS (which is 0), we assume that we have C runtime error and use errno. To get error description we use strerror_win32() with GetLastError() and strerror() with errno. strerror_win32() uses FormatMessage() internally, which is the right way to get WinAPI error description. Signed-off-by: Lev Stipakov Acked-by: Selva Nair Message-Id: <20220503002840.295-1-lstipakov@gmail.com> URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg24270.html Signed-off-by: Gert Doering --- src/openvpn/error.c | 34 +++++++++++++++++++++++++++------- src/openvpn/error.h | 39 +++++++++++++++++++++++++++++---------- src/openvpn/forward.c | 9 ++++++++- src/openvpn/manage.c | 5 +++-- src/openvpn/platform.c | 2 +- src/openvpn/tun.h | 4 ++-- 6 files changed, 70 insertions(+), 23 deletions(-) diff --git a/src/openvpn/error.c b/src/openvpn/error.c index 603d6c630..1b7f5cdec 100644 --- a/src/openvpn/error.c +++ b/src/openvpn/error.c @@ -220,6 +220,18 @@ x_msg(const unsigned int flags, const char *format, ...) va_end(arglist); } +static const char* +openvpn_strerror(int err, bool crt_error, struct gc_arena *gc) +{ +#ifdef _WIN32 + if (!crt_error) + { + return strerror_win32(err, gc); + } +#endif + return strerror(err); +} + void x_msg_va(const unsigned int flags, const char *format, va_list arglist) { @@ -242,7 +254,8 @@ x_msg_va(const unsigned int flags, const char *format, va_list arglist) return; } - e = openvpn_errno(); + bool crt_error = false; + e = openvpn_errno_maybe_crt(&crt_error); /* * Apply muting filter. @@ -264,7 +277,7 @@ x_msg_va(const unsigned int flags, const char *format, va_list arglist) if ((flags & M_ERRNO) && e) { openvpn_snprintf(m2, ERR_BUF_SIZE, "%s: %s (errno=%d)", - m1, strerror(e), e); + m1, openvpn_strerror(e, crt_error, &gc), e); SWAP; } @@ -643,7 +656,6 @@ x_check_status(int status, struct link_socket *sock, struct tuntap *tt) { - const int my_errno = openvpn_errno(); const char *extended_msg = NULL; msg(x_cs_verbose_level, "%s %s returned %d", @@ -666,26 +678,34 @@ x_check_status(int status, sock->info.mtu_changed = true; } } -#elif defined(_WIN32) +#endif /* EXTENDED_SOCKET_ERROR_CAPABILITY */ + +#ifdef _WIN32 /* get possible driver error from TAP-Windows driver */ if (tuntap_defined(tt)) { extended_msg = tap_win_getinfo(tt, &gc); } #endif - if (!ignore_sys_error(my_errno)) + + bool crt_error = false; + int my_errno = openvpn_errno_maybe_crt(&crt_error); + + if (!ignore_sys_error(my_errno, crt_error)) { if (extended_msg) { msg(x_cs_info_level, "%s %s [%s]: %s (fd=%d,code=%d)", description, sock ? proto2ascii(sock->info.proto, sock->info.af, true) : "", - extended_msg, strerror(my_errno), sock ? sock->sd : -1, my_errno); + extended_msg, openvpn_strerror(my_errno, crt_error, &gc), + sock ? sock->sd : -1, my_errno); } else { msg(x_cs_info_level, "%s %s: %s (fd=%d,code=%d)", description, sock ? proto2ascii(sock->info.proto, sock->info.af, true) : "", - strerror(my_errno), sock ? sock->sd : -1, my_errno); + openvpn_strerror(my_errno, crt_error, &gc), + sock ? sock->sd : -1, my_errno); } if (x_cs_err_delay_ms) diff --git a/src/openvpn/error.h b/src/openvpn/error.h index ad7defe80..be8d97e50 100644 --- a/src/openvpn/error.h +++ b/src/openvpn/error.h @@ -75,13 +75,10 @@ struct gc_arena; /* String and Error functions */ #ifdef _WIN32 -#define openvpn_errno() GetLastError() -#define openvpn_strerror(e, gc) strerror_win32(e, gc) +#define openvpn_errno() GetLastError() const char *strerror_win32(DWORD errnum, struct gc_arena *gc); - #else -#define openvpn_errno() errno -#define openvpn_strerror(x, gc) strerror(x) +#define openvpn_errno() errno #endif /* @@ -352,20 +349,22 @@ msg_get_virtual_output(void) * which can be safely ignored. */ static inline bool -ignore_sys_error(const int err) +ignore_sys_error(const int err, bool crt_error) { - /* I/O operation pending */ #ifdef _WIN32 - if (err == WSAEWOULDBLOCK || err == WSAEINVAL) + if (!crt_error && ((err == WSAEWOULDBLOCK || err == WSAEINVAL))) { return true; } #else - if (err == EAGAIN) + crt_error = true; +#endif + + /* I/O operation pending */ + if (crt_error && (err == EAGAIN)) { return true; } -#endif #if 0 /* if enabled, suppress ENOBUFS errors */ #ifdef ENOBUFS @@ -387,6 +386,26 @@ nonfatal(const unsigned int err) return err & M_FATAL ? (err ^ M_FATAL) | M_NONFATAL : err; } +static inline int +openvpn_errno_maybe_crt(bool *crt_error) +{ + int err = 0; + *crt_error = false; +#ifdef _WIN32 + err = GetLastError(); + if (err == ERROR_SUCCESS) + { + /* error is likely C runtime */ + *crt_error = true; + err = errno; + } +#else + *crt_error = true; + err = errno; +#endif + return err; +} + #include "errlevel.h" #endif /* ifndef ERROR_H */ diff --git a/src/openvpn/forward.c b/src/openvpn/forward.c index 8930e578a..04828a5c4 100644 --- a/src/openvpn/forward.c +++ b/src/openvpn/forward.c @@ -1660,7 +1660,14 @@ process_outgoing_link(struct context *c) } /* for unreachable network and "connecting" state switch to the next host */ - if (size < 0 && ENETUNREACH == error_code && c->c2.tls_multi + + bool unreachable = error_code == +#ifdef _WIN32 + WSAENETUNREACH; +#else + ENETUNREACH; +#endif + if (size < 0 && unreachable && c->c2.tls_multi && !tls_initial_packet_received(c->c2.tls_multi) && c->options.mode == MODE_POINT_TO_POINT) { msg(M_INFO, "Network unreachable, restarting"); diff --git a/src/openvpn/manage.c b/src/openvpn/manage.c index e305e4422..aeea5f9ff 100644 --- a/src/openvpn/manage.c +++ b/src/openvpn/manage.c @@ -2008,9 +2008,10 @@ man_process_command(struct management *man, const char *line) static bool man_io_error(struct management *man, const char *prefix) { - const int err = openvpn_errno(); + bool crt_error = false; + int err = openvpn_errno_maybe_crt(&crt_error); - if (!ignore_sys_error(err)) + if (!ignore_sys_error(err, crt_error)) { struct gc_arena gc = gc_new(); msg(D_MANAGEMENT, "MANAGEMENT: TCP %s error: %s", prefix, diff --git a/src/openvpn/platform.c b/src/openvpn/platform.c index 61afee83c..ae1678dba 100644 --- a/src/openvpn/platform.c +++ b/src/openvpn/platform.c @@ -532,7 +532,7 @@ platform_test_file(const char *filename) } else { - if (openvpn_errno() == EACCES) + if (errno == EACCES) { msg( M_WARN | M_ERRNO, "Could not access file '%s'", filename); } diff --git a/src/openvpn/tun.h b/src/openvpn/tun.h index 3a7314c52..4bc359165 100644 --- a/src/openvpn/tun.h +++ b/src/openvpn/tun.h @@ -446,7 +446,7 @@ tuntap_stop(int status) */ if (status < 0) { - return openvpn_errno() == ERROR_FILE_NOT_FOUND; + return GetLastError() == ERROR_FILE_NOT_FOUND; } return false; } @@ -459,7 +459,7 @@ tuntap_abort(int status) */ if (status < 0) { - return openvpn_errno() == ERROR_OPERATION_ABORTED; + return GetLastError() == ERROR_OPERATION_ABORTED; } return false; } -- 2.47.2