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curl/tests/server/sockfilt.c

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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at http://curl.haxx.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include "server_setup.h"
/* Purpose
*
* 1. Accept a TCP connection on a custom port (ipv4 or ipv6), or connect
* to a given (localhost) port.
*
* 2. Get commands on STDIN. Pass data on to the TCP stream.
* Get data from TCP stream and pass on to STDOUT.
*
* This program is made to perform all the socket/stream/connection stuff for
* the test suite's (perl) FTP server. Previously the perl code did all of
* this by its own, but I decided to let this program do the socket layer
* because of several things:
*
* o We want the perl code to work with rather old perl installations, thus
* we cannot use recent perl modules or features.
*
* o We want IPv6 support for systems that provide it, and doing optional IPv6
* support in perl seems if not impossible so at least awkward.
*
* o We want FTP-SSL support, which means that a connection that starts with
* plain sockets needs to be able to "go SSL" in the midst. This would also
* require some nasty perl stuff I'd rather avoid.
*
* (Source originally based on sws.c)
*/
/*
* Signal handling notes for sockfilt
* ----------------------------------
*
* This program is a single-threaded process.
*
* This program is intended to be highly portable and as such it must be kept as
* simple as possible, due to this the only signal handling mechanisms used will
* be those of ANSI C, and used only in the most basic form which is good enough
* for the purpose of this program.
*
* For the above reason and the specific needs of this program signals SIGHUP,
* SIGPIPE and SIGALRM will be simply ignored on systems where this can be done.
* If possible, signals SIGINT and SIGTERM will be handled by this program as an
* indication to cleanup and finish execution as soon as possible. This will be
* achieved with a single signal handler 'exit_signal_handler' for both signals.
*
* The 'exit_signal_handler' upon the first SIGINT or SIGTERM received signal
* will just set to one the global var 'got_exit_signal' storing in global var
* 'exit_signal' the signal that triggered this change.
*
* Nothing fancy that could introduce problems is used, the program at certain
* points in its normal flow checks if var 'got_exit_signal' is set and in case
* this is true it just makes its way out of loops and functions in structured
* and well behaved manner to achieve proper program cleanup and termination.
*
* Even with the above mechanism implemented it is worthwile to note that other
* signals might still be received, or that there might be systems on which it
* is not possible to trap and ignore some of the above signals. This implies
* that for increased portability and reliability the program must be coded as
* if no signal was being ignored or handled at all. Enjoy it!
*/
#ifdef HAVE_SIGNAL_H
#include <signal.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#define ENABLE_CURLX_PRINTF
/* make the curlx header define all printf() functions to use the curlx_*
versions instead */
#include "curlx.h" /* from the private lib dir */
#include "getpart.h"
#include "inet_pton.h"
#include "util.h"
#include "server_sockaddr.h"
#include "warnless.h"
/* include memdebug.h last */
#include "memdebug.h"
#ifdef USE_WINSOCK
#undef EINTR
#define EINTR 4 /* errno.h value */
#undef EAGAIN
#define EAGAIN 11 /* errno.h value */
#undef ENOMEM
#define ENOMEM 12 /* errno.h value */
#undef EINVAL
#define EINVAL 22 /* errno.h value */
#endif
#define DEFAULT_PORT 8999
#ifndef DEFAULT_LOGFILE
#define DEFAULT_LOGFILE "log/sockfilt.log"
#endif
const char *serverlogfile = DEFAULT_LOGFILE;
static bool verbose = FALSE;
static bool bind_only = FALSE;
#ifdef ENABLE_IPV6
static bool use_ipv6 = FALSE;
#endif
static const char *ipv_inuse = "IPv4";
static unsigned short port = DEFAULT_PORT;
static unsigned short connectport = 0; /* if non-zero, we activate this mode */
enum sockmode {
PASSIVE_LISTEN, /* as a server waiting for connections */
PASSIVE_CONNECT, /* as a server, connected to a client */
ACTIVE, /* as a client, connected to a server */
ACTIVE_DISCONNECT /* as a client, disconnected from server */
};
/* do-nothing macro replacement for systems which lack siginterrupt() */
#ifndef HAVE_SIGINTERRUPT
#define siginterrupt(x,y) do {} while(0)
#endif
/* vars used to keep around previous signal handlers */
typedef RETSIGTYPE (*SIGHANDLER_T)(int);
#ifdef SIGHUP
static SIGHANDLER_T old_sighup_handler = SIG_ERR;
#endif
#ifdef SIGPIPE
static SIGHANDLER_T old_sigpipe_handler = SIG_ERR;
#endif
#ifdef SIGALRM
static SIGHANDLER_T old_sigalrm_handler = SIG_ERR;
#endif
#ifdef SIGINT
static SIGHANDLER_T old_sigint_handler = SIG_ERR;
#endif
#ifdef SIGTERM
static SIGHANDLER_T old_sigterm_handler = SIG_ERR;
#endif
#if defined(SIGBREAK) && defined(WIN32)
static SIGHANDLER_T old_sigbreak_handler = SIG_ERR;
#endif
/* var which if set indicates that the program should finish execution */
SIG_ATOMIC_T got_exit_signal = 0;
/* if next is set indicates the first signal handled in exit_signal_handler */
static volatile int exit_signal = 0;
/* signal handler that will be triggered to indicate that the program
should finish its execution in a controlled manner as soon as possible.
The first time this is called it will set got_exit_signal to one and
store in exit_signal the signal that triggered its execution. */
static RETSIGTYPE exit_signal_handler(int signum)
{
int old_errno = errno;
if(got_exit_signal == 0) {
got_exit_signal = 1;
exit_signal = signum;
}
(void)signal(signum, exit_signal_handler);
errno = old_errno;
}
static void install_signal_handlers(void)
{
#ifdef SIGHUP
/* ignore SIGHUP signal */
if((old_sighup_handler = signal(SIGHUP, SIG_IGN)) == SIG_ERR)
logmsg("cannot install SIGHUP handler: %s", strerror(errno));
#endif
#ifdef SIGPIPE
/* ignore SIGPIPE signal */
if((old_sigpipe_handler = signal(SIGPIPE, SIG_IGN)) == SIG_ERR)
logmsg("cannot install SIGPIPE handler: %s", strerror(errno));
#endif
#ifdef SIGALRM
/* ignore SIGALRM signal */
if((old_sigalrm_handler = signal(SIGALRM, SIG_IGN)) == SIG_ERR)
logmsg("cannot install SIGALRM handler: %s", strerror(errno));
#endif
#ifdef SIGINT
/* handle SIGINT signal with our exit_signal_handler */
if((old_sigint_handler = signal(SIGINT, exit_signal_handler)) == SIG_ERR)
logmsg("cannot install SIGINT handler: %s", strerror(errno));
else
siginterrupt(SIGINT, 1);
#endif
#ifdef SIGTERM
/* handle SIGTERM signal with our exit_signal_handler */
if((old_sigterm_handler = signal(SIGTERM, exit_signal_handler)) == SIG_ERR)
logmsg("cannot install SIGTERM handler: %s", strerror(errno));
else
siginterrupt(SIGTERM, 1);
#endif
#if defined(SIGBREAK) && defined(WIN32)
/* handle SIGBREAK signal with our exit_signal_handler */
if((old_sigbreak_handler = signal(SIGBREAK, exit_signal_handler)) == SIG_ERR)
logmsg("cannot install SIGBREAK handler: %s", strerror(errno));
else
siginterrupt(SIGBREAK, 1);
#endif
}
static void restore_signal_handlers(void)
{
#ifdef SIGHUP
if(SIG_ERR != old_sighup_handler)
(void)signal(SIGHUP, old_sighup_handler);
#endif
#ifdef SIGPIPE
if(SIG_ERR != old_sigpipe_handler)
(void)signal(SIGPIPE, old_sigpipe_handler);
#endif
#ifdef SIGALRM
if(SIG_ERR != old_sigalrm_handler)
(void)signal(SIGALRM, old_sigalrm_handler);
#endif
#ifdef SIGINT
if(SIG_ERR != old_sigint_handler)
(void)signal(SIGINT, old_sigint_handler);
#endif
#ifdef SIGTERM
if(SIG_ERR != old_sigterm_handler)
(void)signal(SIGTERM, old_sigterm_handler);
#endif
#if defined(SIGBREAK) && defined(WIN32)
if(SIG_ERR != old_sigbreak_handler)
(void)signal(SIGBREAK, old_sigbreak_handler);
#endif
}
#ifdef WIN32
/*
* read-wrapper to support reading from stdin on Windows.
*/
static ssize_t read_wincon(int fd, void *buf, size_t count)
{
HANDLE handle = NULL;
DWORD mode, rcount = 0;
BOOL success;
if(fd == fileno(stdin)) {
handle = GetStdHandle(STD_INPUT_HANDLE);
}
else {
return read(fd, buf, count);
}
if(GetConsoleMode(handle, &mode)) {
success = ReadConsole(handle, buf, count, &rcount, NULL);
}
else {
success = ReadFile(handle, buf, count, &rcount, NULL);
}
if(success) {
return rcount;
}
errno = GetLastError();
return -1;
}
#undef read
#define read(a,b,c) read_wincon(a,b,c)
/*
* write-wrapper to support writing to stdout and stderr on Windows.
*/
static ssize_t write_wincon(int fd, const void *buf, size_t count)
{
HANDLE handle = NULL;
DWORD mode, wcount = 0;
BOOL success;
if(fd == fileno(stdout)) {
handle = GetStdHandle(STD_OUTPUT_HANDLE);
}
else if(fd == fileno(stderr)) {
handle = GetStdHandle(STD_ERROR_HANDLE);
}
else {
return write(fd, buf, count);
}
if(GetConsoleMode(handle, &mode)) {
success = WriteConsole(handle, buf, count, &wcount, NULL);
}
else {
success = WriteFile(handle, buf, count, &wcount, NULL);
}
if(success) {
return wcount;
}
errno = GetLastError();
return -1;
}
#undef write
#define write(a,b,c) write_wincon(a,b,c)
#endif
/*
* fullread is a wrapper around the read() function. This will repeat the call
* to read() until it actually has read the complete number of bytes indicated
* in nbytes or it fails with a condition that cannot be handled with a simple
* retry of the read call.
*/
static ssize_t fullread(int filedes, void *buffer, size_t nbytes)
{
int error;
ssize_t rc;
ssize_t nread = 0;
do {
rc = read(filedes, (unsigned char *)buffer + nread, nbytes - nread);
if(got_exit_signal) {
logmsg("signalled to die");
return -1;
}
if(rc < 0) {
error = errno;
if((error == EINTR) || (error == EAGAIN))
continue;
logmsg("reading from file descriptor: %d,", filedes);
logmsg("unrecoverable read() failure: (%d) %s",
error, strerror(error));
return -1;
}
if(rc == 0) {
logmsg("got 0 reading from stdin");
return 0;
}
nread += rc;
} while((size_t)nread < nbytes);
if(verbose)
logmsg("read %zd bytes", nread);
return nread;
}
/*
* fullwrite is a wrapper around the write() function. This will repeat the
* call to write() until it actually has written the complete number of bytes
* indicated in nbytes or it fails with a condition that cannot be handled
* with a simple retry of the write call.
*/
static ssize_t fullwrite(int filedes, const void *buffer, size_t nbytes)
{
int error;
ssize_t wc;
ssize_t nwrite = 0;
do {
wc = write(filedes, (unsigned char *)buffer + nwrite, nbytes - nwrite);
if(got_exit_signal) {
logmsg("signalled to die");
return -1;
}
if(wc < 0) {
error = errno;
if((error == EINTR) || (error == EAGAIN))
continue;
logmsg("writing to file descriptor: %d,", filedes);
logmsg("unrecoverable write() failure: (%d) %s",
error, strerror(error));
return -1;
}
if(wc == 0) {
logmsg("put 0 writing to stdout");
return 0;
}
nwrite += wc;
} while((size_t)nwrite < nbytes);
if(verbose)
logmsg("wrote %zd bytes", nwrite);
return nwrite;
}
/*
* read_stdin tries to read from stdin nbytes into the given buffer. This is a
* blocking function that will only return TRUE when nbytes have actually been
* read or FALSE when an unrecoverable error has been detected. Failure of this
* function is an indication that the sockfilt process should terminate.
*/
static bool read_stdin(void *buffer, size_t nbytes)
{
ssize_t nread = fullread(fileno(stdin), buffer, nbytes);
if(nread != (ssize_t)nbytes) {
logmsg("exiting...");
return FALSE;
}
return TRUE;
}
/*
* write_stdout tries to write to stdio nbytes from the given buffer. This is a
* blocking function that will only return TRUE when nbytes have actually been
* written or FALSE when an unrecoverable error has been detected. Failure of
* this function is an indication that the sockfilt process should terminate.
*/
static bool write_stdout(const void *buffer, size_t nbytes)
{
ssize_t nwrite = fullwrite(fileno(stdout), buffer, nbytes);
if(nwrite != (ssize_t)nbytes) {
logmsg("exiting...");
return FALSE;
}
return TRUE;
}
static void lograw(unsigned char *buffer, ssize_t len)
{
char data[120];
ssize_t i;
unsigned char *ptr = buffer;
char *optr = data;
ssize_t width=0;
for(i=0; i<len; i++) {
switch(ptr[i]) {
case '\n':
sprintf(optr, "\\n");
width += 2;
optr += 2;
break;
case '\r':
sprintf(optr, "\\r");
width += 2;
optr += 2;
break;
default:
sprintf(optr, "%c", (ISGRAPH(ptr[i]) || ptr[i]==0x20) ?ptr[i]:'.');
width++;
optr++;
break;
}
if(width>60) {
logmsg("'%s'", data);
width = 0;
optr = data;
}
}
if(width)
logmsg("'%s'", data);
}
#ifdef USE_WINSOCK
/*
* WinSock select() does not support standard file descriptors,
* it can only check SOCKETs. The following function is an attempt
* to re-create a select() function with support for other handle types.
*
* select() function with support for WINSOCK2 sockets and all
* other handle types supported by WaitForMultipleObjectsEx().
*
* TODO: Differentiate between read/write/except for non-SOCKET handles.
*
* http://msdn.microsoft.com/en-us/library/windows/desktop/ms687028.aspx
* http://msdn.microsoft.com/en-us/library/windows/desktop/ms741572.aspx
*/
static DWORD WINAPI select_ws_stdin_wait_thread(LPVOID lpParameter)
{
HANDLE handle;
DWORD mode;
handle = (HANDLE) lpParameter;
if(GetConsoleMode(handle, &mode))
WaitForSingleObjectEx(handle, INFINITE, FALSE);
else
ReadFile(handle, NULL, 0, &mode, NULL);
return 0;
}
static int select_ws(int nfds, fd_set *readfds, fd_set *writefds,
fd_set *exceptfds, struct timeval *timeout)
{
DWORD milliseconds, wait, idx;
WSAEVENT wsaevent, *wsaevents;
WSANETWORKEVENTS wsanetevents;
HANDLE handle, *handles;
curl_socket_t sock, *fdarr, *wsasocks;
long networkevents;
int error, fds;
DWORD nfd = 0, wsa = 0;
int ret = 0;
/* check if the input value is valid */
if(nfds < 0) {
errno = EINVAL;
return -1;
}
/* check if we got descriptors, sleep in case we got none */
if(!nfds) {
Sleep((timeout->tv_sec * 1000) + (timeout->tv_usec / 1000));
return 0;
}
/* allocate internal array for the original input handles */
fdarr = malloc(nfds * sizeof(curl_socket_t));
if(fdarr == NULL) {
errno = ENOMEM;
return -1;
}
/* allocate internal array for the internal event handles */
handles = malloc(nfds * sizeof(HANDLE));
if(handles == NULL) {
errno = ENOMEM;
return -1;
}
/* allocate internal array for the internal socket handles */
wsasocks = malloc(nfds * sizeof(curl_socket_t));
if(wsasocks == NULL) {
errno = ENOMEM;
return -1;
}
/* allocate internal array for the internal WINSOCK2 events */
wsaevents = malloc(nfds * sizeof(WSAEVENT));
if(wsaevents == NULL) {
errno = ENOMEM;
return -1;
}
/* loop over the handles in the input descriptor sets */
for(fds = 0; fds < nfds; fds++) {
networkevents = 0;
handles[nfd] = 0;
if(FD_ISSET(fds, readfds))
networkevents |= FD_READ|FD_ACCEPT|FD_CLOSE;
if(FD_ISSET(fds, writefds))
networkevents |= FD_WRITE|FD_CONNECT;
if(FD_ISSET(fds, exceptfds))
networkevents |= FD_OOB|FD_CLOSE;
/* only wait for events for which we actually care */
if(networkevents) {
fdarr[nfd] = curlx_sitosk(fds);
if(fds == fileno(stdin)) {
handles[nfd] = CreateThread(NULL, 0,
&select_ws_stdin_wait_thread,
GetStdHandle(STD_INPUT_HANDLE),
0, NULL);
}
else if(fds == fileno(stdout)) {
handles[nfd] = GetStdHandle(STD_OUTPUT_HANDLE);
}
else if(fds == fileno(stderr)) {
handles[nfd] = GetStdHandle(STD_ERROR_HANDLE);
}
else {
wsaevent = WSACreateEvent();
if(wsaevent != WSA_INVALID_EVENT) {
error = WSAEventSelect(fds, wsaevent, networkevents);
if(error != SOCKET_ERROR) {
handles[nfd] = wsaevent;
wsasocks[wsa] = curlx_sitosk(fds);
wsaevents[wsa] = wsaevent;
wsa++;
}
else {
handles[nfd] = (HANDLE) curlx_sitosk(fds);
WSACloseEvent(wsaevent);
}
}
}
nfd++;
}
}
/* convert struct timeval to milliseconds */
if(timeout) {
milliseconds = ((timeout->tv_sec * 1000) + (timeout->tv_usec / 1000));
}
else {
milliseconds = INFINITE;
}
/* wait for one of the internal handles to trigger */
wait = WaitForMultipleObjectsEx(nfd, handles, FALSE, milliseconds, FALSE);
/* loop over the internal handles returned in the descriptors */
for(idx = 0; idx < nfd; idx++) {
handle = handles[idx];
sock = fdarr[idx];
fds = curlx_sktosi(sock);
/* check if the current internal handle was triggered */
if(wait != WAIT_FAILED && (wait - WAIT_OBJECT_0) <= idx &&
WaitForSingleObjectEx(handle, 0, FALSE) == WAIT_OBJECT_0) {
/* first handle stdin, stdout and stderr */
if(fds == fileno(stdin)) {
/* stdin is never ready for write or exceptional */
FD_CLR(sock, writefds);
FD_CLR(sock, exceptfds);
}
else if(fds == fileno(stdout) || fds == fileno(stderr)) {
/* stdout and stderr are never ready for read or exceptional */
FD_CLR(sock, readfds);
FD_CLR(sock, exceptfds);
}
else {
/* try to handle the event with the WINSOCK2 functions */
error = WSAEnumNetworkEvents(fds, handle, &wsanetevents);
if(error != SOCKET_ERROR) {
/* remove from descriptor set if not ready for read/accept/close */
if(!(wsanetevents.lNetworkEvents & (FD_READ|FD_ACCEPT|FD_CLOSE)))
FD_CLR(sock, readfds);
/* remove from descriptor set if not ready for write/connect */
if(!(wsanetevents.lNetworkEvents & (FD_WRITE|FD_CONNECT)))
FD_CLR(sock, writefds);
/* HACK:
* use exceptfds together with readfds to signal
* that the connection was closed by the client.
*
* Reason: FD_CLOSE is only signaled once, sometimes
* at the same time as FD_READ with data being available.
* This means that recv/sread is not reliable to detect
* that the connection is closed.
*/
/* remove from descriptor set if not exceptional */
if(!(wsanetevents.lNetworkEvents & (FD_OOB|FD_CLOSE)))
FD_CLR(sock, exceptfds);
}
}
/* check if the event has not been filtered using specific tests */
if(FD_ISSET(sock, readfds) || FD_ISSET(sock, writefds) ||
FD_ISSET(sock, exceptfds)) {
ret++;
}
}
else {
/* remove from all descriptor sets since this handle did not trigger */
FD_CLR(sock, readfds);
FD_CLR(sock, writefds);
FD_CLR(sock, exceptfds);
}
}
for(idx = 0; idx < wsa; idx++) {
WSAEventSelect(wsasocks[idx], NULL, 0);
WSACloseEvent(wsaevents[idx]);
}
free(wsaevents);
free(wsasocks);
free(handles);
free(fdarr);
return ret;
}
#define select(a,b,c,d,e) select_ws(a,b,c,d,e)
#endif /* USE_WINSOCK */
/*
sockfdp is a pointer to an established stream or CURL_SOCKET_BAD
if sockfd is CURL_SOCKET_BAD, listendfd is a listening socket we must
accept()
*/
static bool juggle(curl_socket_t *sockfdp,
curl_socket_t listenfd,
enum sockmode *mode)
{
struct timeval timeout;
fd_set fds_read;
fd_set fds_write;
fd_set fds_err;
curl_socket_t sockfd = CURL_SOCKET_BAD;
int maxfd = -99;
ssize_t rc;
ssize_t nread_socket;
ssize_t bytes_written;
ssize_t buffer_len;
int error = 0;
/* 'buffer' is this excessively large only to be able to support things like
test 1003 which tests exceedingly large server response lines */
unsigned char buffer[17010];
char data[16];
if(got_exit_signal) {
logmsg("signalled to die, exiting...");
return FALSE;
}
#ifdef HAVE_GETPPID
/* As a last resort, quit if sockfilt process becomes orphan. Just in case
parent ftpserver process has died without killing its sockfilt children */
if(getppid() <= 1) {
logmsg("process becomes orphan, exiting");
return FALSE;
}
#endif
timeout.tv_sec = 120;
timeout.tv_usec = 0;
FD_ZERO(&fds_read);
FD_ZERO(&fds_write);
FD_ZERO(&fds_err);
FD_SET((curl_socket_t)fileno(stdin), &fds_read);
switch(*mode) {
case PASSIVE_LISTEN:
/* server mode */
sockfd = listenfd;
/* there's always a socket to wait for */
FD_SET(sockfd, &fds_read);
maxfd = (int)sockfd;
break;
case PASSIVE_CONNECT:
sockfd = *sockfdp;
if(CURL_SOCKET_BAD == sockfd) {
/* eeek, we are supposedly connected and then this cannot be -1 ! */
logmsg("socket is -1! on %s:%d", __FILE__, __LINE__);
maxfd = 0; /* stdin */
}
else {
/* there's always a socket to wait for */
FD_SET(sockfd, &fds_read);
#ifdef USE_WINSOCK
FD_SET(sockfd, &fds_err);
#endif
maxfd = (int)sockfd;
}
break;
case ACTIVE:
sockfd = *sockfdp;
/* sockfd turns CURL_SOCKET_BAD when our connection has been closed */
if(CURL_SOCKET_BAD != sockfd) {
FD_SET(sockfd, &fds_read);
#ifdef USE_WINSOCK
FD_SET(sockfd, &fds_err);
#endif
maxfd = (int)sockfd;
}
else {
logmsg("No socket to read on");
maxfd = 0;
}
break;
case ACTIVE_DISCONNECT:
logmsg("disconnected, no socket to read on");
maxfd = 0;
sockfd = CURL_SOCKET_BAD;
break;
} /* switch(*mode) */
do {
/* select() blocking behavior call on blocking descriptors please */
rc = select(maxfd + 1, &fds_read, &fds_write, &fds_err, &timeout);
if(got_exit_signal) {
logmsg("signalled to die, exiting...");
return FALSE;
}
} while((rc == -1) && ((error = errno) == EINTR));
if(rc < 0) {
logmsg("select() failed with error: (%d) %s",
error, strerror(error));
return FALSE;
}
if(rc == 0)
/* timeout */
return TRUE;
if(FD_ISSET(fileno(stdin), &fds_read)) {
/* read from stdin, commands/data to be dealt with and possibly passed on
to the socket
protocol:
4 letter command + LF [mandatory]
4-digit hexadecimal data length + LF [if the command takes data]
data [the data being as long as set above]
Commands:
DATA - plain pass-thru data
*/
if(!read_stdin(buffer, 5))
return FALSE;
logmsg("Received %c%c%c%c (on stdin)",
buffer[0], buffer[1], buffer[2], buffer[3] );
if(!memcmp("PING", buffer, 4)) {
/* send reply on stdout, just proving we are alive */
if(!write_stdout("PONG\n", 5))
return FALSE;
}
else if(!memcmp("PORT", buffer, 4)) {
/* Question asking us what PORT number we are listening to.
Replies to PORT with "IPv[num]/[port]" */
sprintf((char *)buffer, "%s/%hu\n", ipv_inuse, port);
buffer_len = (ssize_t)strlen((char *)buffer);
snprintf(data, sizeof(data), "PORT\n%04zx\n", buffer_len);
if(!write_stdout(data, 10))
return FALSE;
if(!write_stdout(buffer, buffer_len))
return FALSE;
}
else if(!memcmp("QUIT", buffer, 4)) {
/* just die */
logmsg("quits");
return FALSE;
}
else if(!memcmp("DATA", buffer, 4)) {
/* data IN => data OUT */
if(!read_stdin(buffer, 5))
return FALSE;
buffer[5] = '\0';
buffer_len = (ssize_t)strtol((char *)buffer, NULL, 16);
if (buffer_len > (ssize_t)sizeof(buffer)) {
logmsg("ERROR: Buffer size (%zu bytes) too small for data size "
"(%zd bytes)", sizeof(buffer), buffer_len);
return FALSE;
}
logmsg("> %zd bytes data, server => client", buffer_len);
if(!read_stdin(buffer, buffer_len))
return FALSE;
lograw(buffer, buffer_len);
if(*mode == PASSIVE_LISTEN) {
logmsg("*** We are disconnected!");
if(!write_stdout("DISC\n", 5))
return FALSE;
}
else {
/* send away on the socket */
bytes_written = swrite(sockfd, buffer, buffer_len);
if(bytes_written != buffer_len) {
logmsg("Not all data was sent. Bytes to send: %zd sent: %zd",
buffer_len, bytes_written);
}
}
}
else if(!memcmp("DISC", buffer, 4)) {
/* disconnect! */
if(!write_stdout("DISC\n", 5))
return FALSE;
if(sockfd != CURL_SOCKET_BAD) {
logmsg("====> Client forcibly disconnected");
sclose(sockfd);
*sockfdp = CURL_SOCKET_BAD;
if(*mode == PASSIVE_CONNECT)
*mode = PASSIVE_LISTEN;
else
*mode = ACTIVE_DISCONNECT;
}
else
logmsg("attempt to close already dead connection");
return TRUE;
}
}
if((sockfd != CURL_SOCKET_BAD) && (FD_ISSET(sockfd, &fds_read)) ) {
curl_socket_t newfd = CURL_SOCKET_BAD; /* newly accepted socket */
if(*mode == PASSIVE_LISTEN) {
/* there's no stream set up yet, this is an indication that there's a
client connecting. */
newfd = accept(sockfd, NULL, NULL);
if(CURL_SOCKET_BAD == newfd) {
error = SOCKERRNO;
logmsg("accept(%d, NULL, NULL) failed with error: (%d) %s",
sockfd, error, strerror(error));
}
else {
logmsg("====> Client connect");
if(!write_stdout("CNCT\n", 5))
return FALSE;
*sockfdp = newfd; /* store the new socket */
*mode = PASSIVE_CONNECT; /* we have connected */
}
return TRUE;
}
/* read from socket, pass on data to stdout */
nread_socket = sread(sockfd, buffer, sizeof(buffer));
if(nread_socket > 0) {
snprintf(data, sizeof(data), "DATA\n%04zx\n", nread_socket);
if(!write_stdout(data, 10))
return FALSE;
if(!write_stdout(buffer, nread_socket))
return FALSE;
logmsg("< %zd bytes data, client => server", nread_socket);
lograw(buffer, nread_socket);
}
if(nread_socket <= 0
#ifdef USE_WINSOCK
|| FD_ISSET(sockfd, &fds_err)
#endif
) {
logmsg("====> Client disconnect");
if(!write_stdout("DISC\n", 5))
return FALSE;
sclose(sockfd);
*sockfdp = CURL_SOCKET_BAD;
if(*mode == PASSIVE_CONNECT)
*mode = PASSIVE_LISTEN;
else
*mode = ACTIVE_DISCONNECT;
return TRUE;
}
}
return TRUE;
}
static curl_socket_t sockdaemon(curl_socket_t sock,
unsigned short *listenport)
{
/* passive daemon style */
srvr_sockaddr_union_t listener;
int flag;
int rc;
int totdelay = 0;
int maxretr = 10;
int delay= 20;
int attempt = 0;
int error = 0;
do {
attempt++;
flag = 1;
rc = setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
(void *)&flag, sizeof(flag));
if(rc) {
error = SOCKERRNO;
logmsg("setsockopt(SO_REUSEADDR) failed with error: (%d) %s",
error, strerror(error));
if(maxretr) {
rc = wait_ms(delay);
if(rc) {
/* should not happen */
error = errno;
logmsg("wait_ms() failed with error: (%d) %s",
error, strerror(error));
sclose(sock);
return CURL_SOCKET_BAD;
}
if(got_exit_signal) {
logmsg("signalled to die, exiting...");
sclose(sock);
return CURL_SOCKET_BAD;
}
totdelay += delay;
delay *= 2; /* double the sleep for next attempt */
}
}
} while(rc && maxretr--);
if(rc) {
logmsg("setsockopt(SO_REUSEADDR) failed %d times in %d ms. Error: (%d) %s",
attempt, totdelay, error, strerror(error));
logmsg("Continuing anyway...");
}
/* When the specified listener port is zero, it is actually a
request to let the system choose a non-zero available port. */
#ifdef ENABLE_IPV6
if(!use_ipv6) {
#endif
memset(&listener.sa4, 0, sizeof(listener.sa4));
listener.sa4.sin_family = AF_INET;
listener.sa4.sin_addr.s_addr = INADDR_ANY;
listener.sa4.sin_port = htons(*listenport);
rc = bind(sock, &listener.sa, sizeof(listener.sa4));
#ifdef ENABLE_IPV6
}
else {
memset(&listener.sa6, 0, sizeof(listener.sa6));
listener.sa6.sin6_family = AF_INET6;
listener.sa6.sin6_addr = in6addr_any;
listener.sa6.sin6_port = htons(*listenport);
rc = bind(sock, &listener.sa, sizeof(listener.sa6));
}
#endif /* ENABLE_IPV6 */
if(rc) {
error = SOCKERRNO;
logmsg("Error binding socket on port %hu: (%d) %s",
*listenport, error, strerror(error));
sclose(sock);
return CURL_SOCKET_BAD;
}
if(!*listenport) {
/* The system was supposed to choose a port number, figure out which
port we actually got and update the listener port value with it. */
curl_socklen_t la_size;
srvr_sockaddr_union_t localaddr;
#ifdef ENABLE_IPV6
if(!use_ipv6)
#endif
la_size = sizeof(localaddr.sa4);
#ifdef ENABLE_IPV6
else
la_size = sizeof(localaddr.sa6);
#endif
memset(&localaddr.sa, 0, (size_t)la_size);
if(getsockname(sock, &localaddr.sa, &la_size) < 0) {
error = SOCKERRNO;
logmsg("getsockname() failed with error: (%d) %s",
error, strerror(error));
sclose(sock);
return CURL_SOCKET_BAD;
}
switch (localaddr.sa.sa_family) {
case AF_INET:
*listenport = ntohs(localaddr.sa4.sin_port);
break;
#ifdef ENABLE_IPV6
case AF_INET6:
*listenport = ntohs(localaddr.sa6.sin6_port);
break;
#endif
default:
break;
}
if(!*listenport) {
/* Real failure, listener port shall not be zero beyond this point. */
logmsg("Apparently getsockname() succeeded, with listener port zero.");
logmsg("A valid reason for this failure is a binary built without");
logmsg("proper network library linkage. This might not be the only");
logmsg("reason, but double check it before anything else.");
sclose(sock);
return CURL_SOCKET_BAD;
}
}
/* bindonly option forces no listening */
if(bind_only) {
logmsg("instructed to bind port without listening");
return sock;
}
/* start accepting connections */
rc = listen(sock, 5);
if(0 != rc) {
error = SOCKERRNO;
logmsg("listen(%d, 5) failed with error: (%d) %s",
sock, error, strerror(error));
sclose(sock);
return CURL_SOCKET_BAD;
}
return sock;
}
int main(int argc, char *argv[])
{
srvr_sockaddr_union_t me;
curl_socket_t sock = CURL_SOCKET_BAD;
curl_socket_t msgsock = CURL_SOCKET_BAD;
int wrotepidfile = 0;
char *pidname= (char *)".sockfilt.pid";
bool juggle_again;
int rc;
int error;
int arg=1;
enum sockmode mode = PASSIVE_LISTEN; /* default */
const char *addr = NULL;
while(argc>arg) {
if(!strcmp("--version", argv[arg])) {
printf("sockfilt IPv4%s\n",
#ifdef ENABLE_IPV6
"/IPv6"
#else
""
#endif
);
return 0;
}
else if(!strcmp("--verbose", argv[arg])) {
verbose = TRUE;
arg++;
}
else if(!strcmp("--pidfile", argv[arg])) {
arg++;
if(argc>arg)
pidname = argv[arg++];
}
else if(!strcmp("--logfile", argv[arg])) {
arg++;
if(argc>arg)
serverlogfile = argv[arg++];
}
else if(!strcmp("--ipv6", argv[arg])) {
#ifdef ENABLE_IPV6
ipv_inuse = "IPv6";
use_ipv6 = TRUE;
#endif
arg++;
}
else if(!strcmp("--ipv4", argv[arg])) {
/* for completeness, we support this option as well */
#ifdef ENABLE_IPV6
ipv_inuse = "IPv4";
use_ipv6 = FALSE;
#endif
arg++;
}
else if(!strcmp("--bindonly", argv[arg])) {
bind_only = TRUE;
arg++;
}
else if(!strcmp("--port", argv[arg])) {
arg++;
if(argc>arg) {
char *endptr;
unsigned long ulnum = strtoul(argv[arg], &endptr, 10);
if((endptr != argv[arg] + strlen(argv[arg])) ||
((ulnum != 0UL) && ((ulnum < 1025UL) || (ulnum > 65535UL)))) {
fprintf(stderr, "sockfilt: invalid --port argument (%s)\n",
argv[arg]);
return 0;
}
port = curlx_ultous(ulnum);
arg++;
}
}
else if(!strcmp("--connect", argv[arg])) {
/* Asked to actively connect to the specified local port instead of
doing a passive server-style listening. */
arg++;
if(argc>arg) {
char *endptr;
unsigned long ulnum = strtoul(argv[arg], &endptr, 10);
if((endptr != argv[arg] + strlen(argv[arg])) ||
(ulnum < 1025UL) || (ulnum > 65535UL)) {
fprintf(stderr, "sockfilt: invalid --connect argument (%s)\n",
argv[arg]);
return 0;
}
connectport = curlx_ultous(ulnum);
arg++;
}
}
else if(!strcmp("--addr", argv[arg])) {
/* Set an IP address to use with --connect; otherwise use localhost */
arg++;
if(argc>arg) {
addr = argv[arg];
arg++;
}
}
else {
puts("Usage: sockfilt [option]\n"
" --version\n"
" --verbose\n"
" --logfile [file]\n"
" --pidfile [file]\n"
" --ipv4\n"
" --ipv6\n"
" --bindonly\n"
" --port [port]\n"
" --connect [port]\n"
" --addr [address]");
return 0;
}
}
#ifdef WIN32
win32_init();
atexit(win32_cleanup);
setmode(fileno(stdin), O_BINARY);
setmode(fileno(stdout), O_BINARY);
setmode(fileno(stderr), O_BINARY);
#endif
install_signal_handlers();
#ifdef ENABLE_IPV6
if(!use_ipv6)
#endif
sock = socket(AF_INET, SOCK_STREAM, 0);
#ifdef ENABLE_IPV6
else
sock = socket(AF_INET6, SOCK_STREAM, 0);
#endif
if(CURL_SOCKET_BAD == sock) {
error = SOCKERRNO;
logmsg("Error creating socket: (%d) %s",
error, strerror(error));
write_stdout("FAIL\n", 5);
goto sockfilt_cleanup;
}
if(connectport) {
/* Active mode, we should connect to the given port number */
mode = ACTIVE;
#ifdef ENABLE_IPV6
if(!use_ipv6) {
#endif
memset(&me.sa4, 0, sizeof(me.sa4));
me.sa4.sin_family = AF_INET;
me.sa4.sin_port = htons(connectport);
me.sa4.sin_addr.s_addr = INADDR_ANY;
if (!addr)
addr = "127.0.0.1";
Curl_inet_pton(AF_INET, addr, &me.sa4.sin_addr);
rc = connect(sock, &me.sa, sizeof(me.sa4));
#ifdef ENABLE_IPV6
}
else {
memset(&me.sa6, 0, sizeof(me.sa6));
me.sa6.sin6_family = AF_INET6;
me.sa6.sin6_port = htons(connectport);
if (!addr)
addr = "::1";
Curl_inet_pton(AF_INET6, addr, &me.sa6.sin6_addr);
rc = connect(sock, &me.sa, sizeof(me.sa6));
}
#endif /* ENABLE_IPV6 */
if(rc) {
error = SOCKERRNO;
logmsg("Error connecting to port %hu: (%d) %s",
connectport, error, strerror(error));
write_stdout("FAIL\n", 5);
goto sockfilt_cleanup;
}
logmsg("====> Client connect");
msgsock = sock; /* use this as stream */
}
else {
/* passive daemon style */
sock = sockdaemon(sock, &port);
if(CURL_SOCKET_BAD == sock) {
write_stdout("FAIL\n", 5);
goto sockfilt_cleanup;
}
msgsock = CURL_SOCKET_BAD; /* no stream socket yet */
}
logmsg("Running %s version", ipv_inuse);
if(connectport)
logmsg("Connected to port %hu", connectport);
else if(bind_only)
logmsg("Bound without listening on port %hu", port);
else
logmsg("Listening on port %hu", port);
wrotepidfile = write_pidfile(pidname);
if(!wrotepidfile) {
write_stdout("FAIL\n", 5);
goto sockfilt_cleanup;
}
do {
juggle_again = juggle(&msgsock, sock, &mode);
} while(juggle_again);
sockfilt_cleanup:
if((msgsock != sock) && (msgsock != CURL_SOCKET_BAD))
sclose(msgsock);
if(sock != CURL_SOCKET_BAD)
sclose(sock);
if(wrotepidfile)
unlink(pidname);
restore_signal_handlers();
if(got_exit_signal) {
logmsg("============> sockfilt exits with signal (%d)", exit_signal);
/*
* To properly set the return status of the process we
* must raise the same signal SIGINT or SIGTERM that we
* caught and let the old handler take care of it.
*/
raise(exit_signal);
}
logmsg("============> sockfilt quits");
return 0;
}
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