[exim.git] / src / src / transports / smtp_socks.c

/*************************************************
*     Exim - an Internet mail transport agent    *
*************************************************/

/* Copyright (c) Jeremy Harris 2015 */
/* See the file NOTICE for conditions of use and distribution. */

/* SOCKS version 5 proxy, client-mode */

#include "../exim.h"
#include "smtp.h"

#ifdef SUPPORT_SOCKS /* entire file */

#ifndef nelem
# define nelem(arr) (sizeof(arr)/sizeof(*arr))
#endif


/* Defaults */
#define SOCKS_PORT	1080
#define SOCKS_TIMEOUT	5
#define SOCKS_WEIGHT	1
#define SOCKS_PRIORITY	1

#define AUTH_NONE	0
#define AUTH_NAME	2		/* user/password per RFC 1929 */
#define AUTH_NAME_VER	1

struct socks_err
  {
  uschar *	reason;
  int		errcode;
  } socks_errs[] =
  {
    {NULL, 0},
    {US"general SOCKS server failure",		EIO},
    {US"connection not allowed by ruleset",	EACCES},
    {US"Network unreachable",			ENETUNREACH},
    {US"Host unreachable",			EHOSTUNREACH},
    {US"Connection refused",			ECONNREFUSED},
    {US"TTL expired",				ECANCELED},
    {US"Command not supported",			EOPNOTSUPP},
    {US"Address type not supported",		EAFNOSUPPORT}
  };

typedef struct
  {
  const uschar *	proxy_host;
  uschar		auth_type;	/* RFC 1928 encoding */
  const uschar *	auth_name;
  const uschar *	auth_pwd;
  short			port;
  BOOL			is_failed;
  unsigned		timeout;
  unsigned		weight;
  unsigned		priority;
  } socks_opts;

static void
socks_option_defaults(socks_opts * sob)
{
sob->proxy_host = NULL;
sob->auth_type =  AUTH_NONE;
sob->auth_name =  US"";
sob->auth_pwd =   US"";
sob->is_failed =  FALSE;
sob->port =	  SOCKS_PORT;
sob->timeout =	  SOCKS_TIMEOUT;
sob->weight =	  SOCKS_WEIGHT;
sob->priority =   SOCKS_PRIORITY;
}

static void
socks_option(socks_opts * sob, const uschar * opt)
{
const uschar * s;

if (Ustrncmp(opt, "auth=", 5) == 0)
  {
  opt += 5;
  if (Ustrcmp(opt, "none") == 0) 	sob->auth_type = AUTH_NONE;
  else if (Ustrcmp(opt, "name") == 0)	sob->auth_type = AUTH_NAME;
  }
else if (Ustrncmp(opt, "name=", 5) == 0)
  sob->auth_name = opt + 5;
else if (Ustrncmp(opt, "pass=", 5) == 0)
  sob->auth_pwd = opt + 5;
else if (Ustrncmp(opt, "port=", 5) == 0)
  sob->port = atoi(opt + 5);
else if (Ustrncmp(opt, "tmo=", 4) == 0)
  sob->timeout = atoi(opt + 4);
else if (Ustrncmp(opt, "pri=", 4) == 0)
  sob->priority = atoi(opt + 4);
else if (Ustrncmp(opt, "weight=", 7) == 0)
  sob->weight = atoi(opt + 7);
return;
}

static int
socks_auth(int fd, int method, socks_opts * sob, time_t tmo)
{
uschar * s;
int len, i, j;

switch(method)
  {
  default:
    log_write(0, LOG_MAIN|LOG_PANIC,
      "Unrecognised socks auth method %d", method);
    return FAIL;
  case AUTH_NONE:
    return OK;
  case AUTH_NAME:
    HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("  socks auth NAME '%s' '%s'\n",
      sob->auth_name, sob->auth_pwd);
    i = Ustrlen(sob->auth_name);
    j = Ustrlen(sob->auth_pwd);
    s = string_sprintf("%c%c%.255s%c%.255s", AUTH_NAME_VER,
      i, sob->auth_name, j, sob->auth_pwd);
    len = i + j + 3;
    HDEBUG(D_transport|D_acl|D_v)
      {
      int i;
      debug_printf_indent("  SOCKS>>");
      for (i = 0; i<len; i++) debug_printf(" %02x", s[i]);
      debug_printf("\n");
      }
    if (send(fd, s, len, 0) < 0)
      return FAIL;
#ifdef TCP_QUICKACK
    (void) setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
#endif
    if (!fd_ready(fd, tmo-time(NULL)) || read(fd, s, 2) != 2)
      return FAIL;
    HDEBUG(D_transport|D_acl|D_v)
      debug_printf_indent("  SOCKS<< %02x %02x\n", s[0], s[1]);
    if (s[0] == AUTH_NAME_VER && s[1] == 0)
      {
      HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("  socks auth OK\n");
      return OK;
      }

    log_write(0, LOG_MAIN|LOG_PANIC, "socks auth failed");
    errno = EPROTO;
    return FAIL;
  }
}


/* Find a suitable proxy to use from the list.
Possible common code with spamd_get_server() ?

Return: index into proxy spec array, or -1
*/

static int
socks_get_proxy(socks_opts * proxies, unsigned nproxies)
{
unsigned int i;
socks_opts * sd;
socks_opts * lim = &proxies[nproxies];
long rnd, weights;
unsigned pri;
static BOOL srandomed = FALSE;

if (nproxies == 1)		/* shortcut, if we have only 1 server */
  return (proxies[0].is_failed ? -1 : 0);

/* init random */
if (!srandomed)
  {
  struct timeval tv;
  gettimeofday(&tv, NULL);
  srandom((unsigned int)(tv.tv_usec/1000));
  srandomed = TRUE;
  }

/* scan for highest pri */
for (pri = 0, sd = proxies; sd < lim; sd++)
  if (!sd->is_failed && sd->priority > pri)
    pri = sd->priority;

/* get sum of weights at this pri */
for (weights = 0, sd = proxies; sd < lim; sd++)
  if (!sd->is_failed && sd->priority == pri)
    weights += sd->weight;
if (weights == 0)       /* all servers failed */
  return -1;

for (rnd = random() % weights, i = 0; i < nproxies; i++)
  {
  sd = &proxies[i];
  if (!sd->is_failed && sd->priority == pri)
    if ((rnd -= sd->weight) <= 0)
      return i;
  }

log_write(0, LOG_MAIN|LOG_PANIC,
  "%s unknown error (memory/cpu corruption?)", __FUNCTION__);
return -1;
}


/* Make a connection via a socks proxy

Arguments:
 host		smtp target host
 host_af	address family
 port		remote tcp port number
 interface	local interface
 tb		transport
 timeout	connection timeout (zero for indefinite)

Return value:
 0 on success; -1 on failure, with errno set
*/

int
socks_sock_connect(host_item * host, int host_af, int port, uschar * interface,
  transport_instance * tb, int timeout)
{
smtp_transport_options_block * ob =
  (smtp_transport_options_block *)tb->options_block;
const uschar * proxy_list;
const uschar * proxy_spec;
int sep = 0;
int fd;
time_t tmo;
const uschar * state;
uschar buf[24];
socks_opts proxies[32];			/* max #proxies handled */
unsigned nproxies;
socks_opts * sob;
unsigned size;
blob early_data;

if (!timeout) timeout = 24*60*60;	/* use 1 day for "indefinite" */
tmo = time(NULL) + timeout;

if (!(proxy_list = expand_string(ob->socks_proxy)))
  {
  log_write(0, LOG_MAIN|LOG_PANIC, "Bad expansion for socks_proxy in %s",
    tb->name);
  return -1;
  }

/* Read proxy list */

for (nproxies = 0;
        nproxies < nelem(proxies)
     && (proxy_spec = string_nextinlist(&proxy_list, &sep, NULL, 0));
     nproxies++)
  {
  int subsep = -' ';
  const uschar * option;

  socks_option_defaults(sob = &proxies[nproxies]);

  if (!(sob->proxy_host = string_nextinlist(&proxy_spec, &subsep, NULL, 0)))
    {
    /* paniclog config error */
    return -1;
    }

  /*XXX consider global options eg. "hide socks_password = wibble" on the tpt */
  /* extract any further per-proxy options */
  while ((option = string_nextinlist(&proxy_spec, &subsep, NULL, 0)))
    socks_option(sob, option);
  }

/* Set up the socks protocol method-selection message,
for sending on connection */

state = US"method select";
buf[0] = 5; buf[1] = 1; buf[2] = sob->auth_type;
early_data.data = buf;
early_data.len = 3;

/* Try proxies until a connection succeeds */

for(;;)
  {
  int idx;
  host_item proxy;
  int proxy_af;

  if ((idx = socks_get_proxy(proxies, nproxies)) < 0)
    {
    HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("  no proxies left\n");
    errno = EBUSY;
    return -1;
    }
  sob = &proxies[idx];

  /* bodge up a host struct for the proxy */
  proxy.address = proxy.name = sob->proxy_host;
  proxy_af = Ustrchr(sob->proxy_host, ':') ? AF_INET6 : AF_INET;

  if ((fd = smtp_sock_connect(&proxy, proxy_af, sob->port,
	      interface, tb, sob->timeout, &early_data)) >= 0)
    {
    proxy_local_address = string_copy(proxy.address);
    proxy_local_port = sob->port;
    break;
    }

  log_write(0, LOG_MAIN, "%s: %s", __FUNCTION__, strerror(errno));
  sob->is_failed = TRUE;
  }

/* Do the socks protocol stuff */

HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("  SOCKS>> 05 01 %02x\n", sob->auth_type);

/* expect method response */

#ifdef TCP_QUICKACK
(void) setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
#endif

if (  !fd_ready(fd, tmo-time(NULL))
   || read(fd, buf, 2) != 2
   )
  goto rcv_err;
HDEBUG(D_transport|D_acl|D_v)
  debug_printf_indent("  SOCKS<< %02x %02x\n", buf[0], buf[1]);
if (  buf[0] != 5
   || socks_auth(fd, buf[1], sob, tmo) != OK
   )
  goto proxy_err;

  {
  union sockaddr_46 sin;
  (void) ip_addr(&sin, host_af, host->address, port);

  /* send connect (ipver, ipaddr, port) */

  buf[0] = 5; buf[1] = 1; buf[2] = 0; buf[3] = host_af == AF_INET6 ? 4 : 1;
  #if HAVE_IPV6
  if (host_af == AF_INET6)
    {
    memcpy(buf+4, &sin.v6.sin6_addr,       sizeof(sin.v6.sin6_addr));
    memcpy(buf+4+sizeof(sin.v6.sin6_addr),
      &sin.v6.sin6_port, sizeof(sin.v6.sin6_port));
    size = 4+sizeof(sin.v6.sin6_addr)+sizeof(sin.v6.sin6_port);
    }
  else
  #endif
    {
    memcpy(buf+4, &sin.v4.sin_addr.s_addr, sizeof(sin.v4.sin_addr.s_addr));
    memcpy(buf+4+sizeof(sin.v4.sin_addr.s_addr),
      &sin.v4.sin_port, sizeof(sin.v4.sin_port));
    size = 4+sizeof(sin.v4.sin_addr.s_addr)+sizeof(sin.v4.sin_port);
    }
  }

state = US"connect";
HDEBUG(D_transport|D_acl|D_v)
  {
  int i;
  debug_printf_indent("  SOCKS>>");
  for (i = 0; i<size; i++) debug_printf(" %02x", buf[i]);
  debug_printf("\n");
  }
if (send(fd, buf, size, 0) < 0)
  goto snd_err;

/* expect conn-reply (success, local(ipver, addr, port))
of same length as conn-request, or non-success fail code */

if (  !fd_ready(fd, tmo-time(NULL))
   || (size = read(fd, buf, size)) < 2
   )
  goto rcv_err;
HDEBUG(D_transport|D_acl|D_v)
  {
  int i;
  debug_printf_indent("  SOCKS>>");
  for (i = 0; i<size; i++) debug_printf(" %02x", buf[i]);
  debug_printf("\n");
  }
if (  buf[0] != 5
   || buf[1] != 0
   )
  goto proxy_err;

proxy_external_address = string_copy(
  host_ntoa(buf[3] == 4 ? AF_INET6 : AF_INET, buf+4, NULL, NULL));
proxy_external_port = ntohs(*((uint16_t *)(buf + (buf[3] == 4 ? 20 : 8))));
proxy_session = TRUE;

HDEBUG(D_transport|D_acl|D_v)
  debug_printf_indent("  proxy farside: [%s]:%d\n", proxy_external_address, proxy_external_port);

return fd;

snd_err:
  HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("  proxy snd_err %s: %s\n", state, strerror(errno));
  return -1;

proxy_err:
  {
  struct socks_err * se =
    buf[1] > nelem(socks_errs) ? NULL : socks_errs + buf[1];
  HDEBUG(D_transport|D_acl|D_v)
    debug_printf_indent("  proxy %s: %s\n", state, se ? se->reason : US"unknown error code received");
  errno = se ? se->errcode : EPROTO;
  }

rcv_err:
  HDEBUG(D_transport|D_acl|D_v) debug_printf_indent("  proxy rcv_err %s: %s\n", state, strerror(errno));
  if (!errno) errno = EPROTO;
  else if (errno == ENOENT) errno = ECONNABORTED;
  return -1;
}

#endif	/* entire file */
/* vi: aw ai sw=2
*/
Commit	Line	Data
7eb6c37c JH	1	/*************************************************
	2	* Exim - an Internet mail transport agent *
	3	*************************************************/
	4
	5	/* Copyright (c) Jeremy Harris 2015 */
	6	/* See the file NOTICE for conditions of use and distribution. */
	7
	8	/* SOCKS version 5 proxy, client-mode */
	9
	10	#include "../exim.h"
	11	#include "smtp.h"
	12
f0989ec0	13	#ifdef SUPPORT_SOCKS /* entire file */
7eb6c37c JH	14
	15	#ifndef nelem
	16	# define nelem(arr) (sizeof(arr)/sizeof(*arr))
	17	#endif
	18
	19
	20	/* Defaults */
	21	#define SOCKS_PORT 1080
	22	#define SOCKS_TIMEOUT 5
7f06582c JH	23	#define SOCKS_WEIGHT 1
7f06582c JH	24	#define SOCKS_PRIORITY 1
7eb6c37c JH	25
	26	#define AUTH_NONE 0
	27	#define AUTH_NAME 2 /* user/password per RFC 1929 */
	28	#define AUTH_NAME_VER 1
	29
	30	struct socks_err
	31	{
	32	uschar * reason;
	33	int errcode;
	34	} socks_errs[] =
	35	{
	36	{NULL, 0},
	37	{US"general SOCKS server failure", EIO},
	38	{US"connection not allowed by ruleset", EACCES},
	39	{US"Network unreachable", ENETUNREACH},
	40	{US"Host unreachable", EHOSTUNREACH},
	41	{US"Connection refused", ECONNREFUSED},
	42	{US"TTL expired", ECANCELED},
	43	{US"Command not supported", EOPNOTSUPP},
	44	{US"Address type not supported", EAFNOSUPPORT}
	45	};
	46
	47	typedef struct
	48	{
7f06582c	49	const uschar * proxy_host;
7eb6c37c JH	50	uschar auth_type; /* RFC 1928 encoding */
	51	const uschar * auth_name;
	52	const uschar * auth_pwd;
	53	short port;
7f06582c	54	BOOL is_failed;
7eb6c37c	55	unsigned timeout;
7f06582c JH	56	unsigned weight;
7f06582c JH	57	unsigned priority;
7eb6c37c JH	58	} socks_opts;
	59
	60	static void
	61	socks_option_defaults(socks_opts * sob)
	62	{
7f06582c JH	63	sob->proxy_host = NULL;
	64	sob->auth_type = AUTH_NONE;
	65	sob->auth_name = US"";
	66	sob->auth_pwd = US"";
	67	sob->is_failed = FALSE;
	68	sob->port = SOCKS_PORT;
	69	sob->timeout = SOCKS_TIMEOUT;
	70	sob->weight = SOCKS_WEIGHT;
	71	sob->priority = SOCKS_PRIORITY;
7eb6c37c JH	72	}
	73
	74	static void
	75	socks_option(socks_opts * sob, const uschar * opt)
	76	{
	77	const uschar * s;
	78
	79	if (Ustrncmp(opt, "auth=", 5) == 0)
	80	{
	81	opt += 5;
	82	if (Ustrcmp(opt, "none") == 0) sob->auth_type = AUTH_NONE;
	83	else if (Ustrcmp(opt, "name") == 0) sob->auth_type = AUTH_NAME;
	84	}
	85	else if (Ustrncmp(opt, "name=", 5) == 0)
	86	sob->auth_name = opt + 5;
	87	else if (Ustrncmp(opt, "pass=", 5) == 0)
	88	sob->auth_pwd = opt + 5;
	89	else if (Ustrncmp(opt, "port=", 5) == 0)
	90	sob->port = atoi(opt + 5);
	91	else if (Ustrncmp(opt, "tmo=", 4) == 0)
	92	sob->timeout = atoi(opt + 4);
7f06582c JH	93	else if (Ustrncmp(opt, "pri=", 4) == 0)
	94	sob->priority = atoi(opt + 4);
	95	else if (Ustrncmp(opt, "weight=", 7) == 0)
	96	sob->weight = atoi(opt + 7);
7eb6c37c JH	97	return;
	98	}
	99
	100	static int
	101	socks_auth(int fd, int method, socks_opts * sob, time_t tmo)
	102	{
	103	uschar * s;
	104	int len, i, j;
	105
	106	switch(method)
	107	{
	108	default:
	109	log_write(0, LOG_MAIN\|LOG_PANIC,
	110	"Unrecognised socks auth method %d", method);
	111	return FAIL;
	112	case AUTH_NONE:
	113	return OK;
	114	case AUTH_NAME:
e1d04f48	115	HDEBUG(D_transport\|D_acl\|D_v) debug_printf_indent(" socks auth NAME '%s' '%s'\n",
7eb6c37c JH	116	sob->auth_name, sob->auth_pwd);
	117	i = Ustrlen(sob->auth_name);
	118	j = Ustrlen(sob->auth_pwd);
	119	s = string_sprintf("%c%c%.255s%c%.255s", AUTH_NAME_VER,
	120	i, sob->auth_name, j, sob->auth_pwd);
	121	len = i + j + 3;
	122	HDEBUG(D_transport\|D_acl\|D_v)
	123	{
	124	int i;
e1d04f48	125	debug_printf_indent(" SOCKS>>");
7eb6c37c JH	126	for (i = 0; i<len; i++) debug_printf(" %02x", s[i]);
	127	debug_printf("\n");
	128	}
1ccd5f67 JH	129	if (send(fd, s, len, 0) < 0)
	130	return FAIL;
	131	#ifdef TCP_QUICKACK
	132	(void) setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
	133	#endif
	134	if (!fd_ready(fd, tmo-time(NULL)) \|\| read(fd, s, 2) != 2)
7eb6c37c JH	135	return FAIL;
7eb6c37c JH	136	HDEBUG(D_transport\|D_acl\|D_v)
e1d04f48	137	debug_printf_indent(" SOCKS<< %02x %02x\n", s[0], s[1]);
7eb6c37c JH	138	if (s[0] == AUTH_NAME_VER && s[1] == 0)
7eb6c37c JH	139	{
e1d04f48	140	HDEBUG(D_transport\|D_acl\|D_v) debug_printf_indent(" socks auth OK\n");
7eb6c37c JH	141	return OK;
	142	}
	143
	144	log_write(0, LOG_MAIN\|LOG_PANIC, "socks auth failed");
	145	errno = EPROTO;
	146	return FAIL;
	147	}
	148	}
	149
	150
	151
7f06582c JH	152	/* Find a suitable proxy to use from the list.
	153	Possible common code with spamd_get_server() ?
	154
	155	Return: index into proxy spec array, or -1
	156	*/
	157
	158	static int
	159	socks_get_proxy(socks_opts * proxies, unsigned nproxies)
	160	{
	161	unsigned int i;
	162	socks_opts * sd;
	163	socks_opts * lim = &proxies[nproxies];
	164	long rnd, weights;
	165	unsigned pri;
	166	static BOOL srandomed = FALSE;
	167
	168	if (nproxies == 1) /* shortcut, if we have only 1 server */
	169	return (proxies[0].is_failed ? -1 : 0);
	170
	171	/* init random */
	172	if (!srandomed)
	173	{
	174	struct timeval tv;
	175	gettimeofday(&tv, NULL);
	176	srandom((unsigned int)(tv.tv_usec/1000));
	177	srandomed = TRUE;
	178	}
	179
	180	/* scan for highest pri */
	181	for (pri = 0, sd = proxies; sd < lim; sd++)
	182	if (!sd->is_failed && sd->priority > pri)
	183	pri = sd->priority;
	184
	185	/* get sum of weights at this pri */
	186	for (weights = 0, sd = proxies; sd < lim; sd++)
	187	if (!sd->is_failed && sd->priority == pri)
	188	weights += sd->weight;
	189	if (weights == 0) /* all servers failed */
	190	return -1;
	191
	192	for (rnd = random() % weights, i = 0; i < nproxies; i++)
	193	{
	194	sd = &proxies[i];
	195	if (!sd->is_failed && sd->priority == pri)
	196	if ((rnd -= sd->weight) <= 0)
	197	return i;
	198	}
	199
	200	log_write(0, LOG_MAIN\|LOG_PANIC,
	201	"%s unknown error (memory/cpu corruption?)", __FUNCTION__);
	202	return -1;
	203	}
	204
	205
	206
7eb6c37c JH	207	/* Make a connection via a socks proxy
	208
	209	Arguments:
	210	host smtp target host
	211	host_af address family
	212	port remote tcp port number
	213	interface local interface
	214	tb transport
	215	timeout connection timeout (zero for indefinite)
	216
	217	Return value:
	218	0 on success; -1 on failure, with errno set
	219	*/
	220
	221	int
	222	socks_sock_connect(host_item * host, int host_af, int port, uschar * interface,
	223	transport_instance * tb, int timeout)
7eb6c37c JH	224	{
	225	smtp_transport_options_block * ob =
	226	(smtp_transport_options_block *)tb->options_block;
	227	const uschar * proxy_list;
	228	const uschar * proxy_spec;
	229	int sep = 0;
	230	int fd;
	231	time_t tmo;
	232	const uschar * state;
	233	uschar buf[24];
7f06582c JH	234	socks_opts proxies[32]; /* max #proxies handled */
	235	unsigned nproxies;
	236	socks_opts * sob;
	237	unsigned size;
0ab63f3d	238	blob early_data;
7eb6c37c JH	239
	240	if (!timeout) timeout = 246060; /* use 1 day for "indefinite" */
	241	tmo = time(NULL) + timeout;
	242
	243	if (!(proxy_list = expand_string(ob->socks_proxy)))
	244	{
	245	log_write(0, LOG_MAIN\|LOG_PANIC, "Bad expansion for socks_proxy in %s",
	246	tb->name);
	247	return -1;
	248	}
	249
7f06582c JH	250	/* Read proxy list */
	251
	252	for (nproxies = 0;
	253	nproxies < nelem(proxies)
	254	&& (proxy_spec = string_nextinlist(&proxy_list, &sep, NULL, 0));
	255	nproxies++)
7eb6c37c	256	{
7eb6c37c	257	int subsep = -' ';
7eb6c37c JH	258	const uschar * option;
7eb6c37c JH	259
7f06582c JH	260	socks_option_defaults(sob = &proxies[nproxies]);
	261
	262	if (!(sob->proxy_host = string_nextinlist(&proxy_spec, &subsep, NULL, 0)))
7eb6c37c JH	263	{
	264	/* paniclog config error */
	265	return -1;
	266	}
	267
	268	/XXX consider global options eg. "hide socks_password = wibble" on the tpt /
7eb6c37c JH	269	/* extract any further per-proxy options */
7eb6c37c JH	270	while ((option = string_nextinlist(&proxy_spec, &subsep, NULL, 0)))
7f06582c JH	271	socks_option(sob, option);
	272	}
	273
0ab63f3d JH	274	/* Set up the socks protocol method-selection message,
	275	for sending on connection */
	276
	277	state = US"method select";
	278	buf[0] = 5; buf[1] = 1; buf[2] = sob->auth_type;
	279	early_data.data = buf;
	280	early_data.len = 3;
	281
7f06582c JH	282	/* Try proxies until a connection succeeds */
	283
	284	for(;;)
	285	{
	286	int idx;
	287	host_item proxy;
	288	int proxy_af;
	289
	290	if ((idx = socks_get_proxy(proxies, nproxies)) < 0)
	291	{
e1d04f48	292	HDEBUG(D_transport\|D_acl\|D_v) debug_printf_indent(" no proxies left\n");
7f06582c JH	293	errno = EBUSY;
	294	return -1;
	295	}
	296	sob = &proxies[idx];
7eb6c37c JH	297
7eb6c37c JH	298	/* bodge up a host struct for the proxy */
848214f7	299	proxy.address = proxy.name = sob->proxy_host;
7f06582c	300	proxy_af = Ustrchr(sob->proxy_host, ':') ? AF_INET6 : AF_INET;
7eb6c37c	301
7f06582c	302	if ((fd = smtp_sock_connect(&proxy, proxy_af, sob->port,
0ab63f3d	303	interface, tb, sob->timeout, &early_data)) >= 0)
e6d2a989 JH	304	{
	305	proxy_local_address = string_copy(proxy.address);
	306	proxy_local_port = sob->port;
7f06582c	307	break;
e6d2a989	308	}
7f06582c JH	309
	310	log_write(0, LOG_MAIN, "%s: %s", __FUNCTION__, strerror(errno));
	311	sob->is_failed = TRUE;
	312	}
	313
	314	/* Do the socks protocol stuff */
7f06582c	315
e1d04f48	316	HDEBUG(D_transport\|D_acl\|D_v) debug_printf_indent(" SOCKS>> 05 01 %02x\n", sob->auth_type);
7f06582c JH	317
	318	/* expect method response */
	319
1ccd5f67 JH	320	#ifdef TCP_QUICKACK
	321	(void) setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
	322	#endif
	323
7f06582c JH	324	if ( !fd_ready(fd, tmo-time(NULL))
	325	\|\| read(fd, buf, 2) != 2
	326	)
	327	goto rcv_err;
	328	HDEBUG(D_transport\|D_acl\|D_v)
e1d04f48	329	debug_printf_indent(" SOCKS<< %02x %02x\n", buf[0], buf[1]);
7f06582c JH	330	if ( buf[0] != 5
	331	\|\| socks_auth(fd, buf[1], sob, tmo) != OK
	332	)
	333	goto proxy_err;
	334
	335	{
	336	union sockaddr_46 sin;
7eb6c37c JH	337	(void) ip_addr(&sin, host_af, host->address, port);
	338
	339	/* send connect (ipver, ipaddr, port) */
7f06582c	340
7eb6c37c	341	buf[0] = 5; buf[1] = 1; buf[2] = 0; buf[3] = host_af == AF_INET6 ? 4 : 1;
7f06582c	342	#if HAVE_IPV6
7eb6c37c JH	343	if (host_af == AF_INET6)
	344	{
	345	memcpy(buf+4, &sin.v6.sin6_addr, sizeof(sin.v6.sin6_addr));
	346	memcpy(buf+4+sizeof(sin.v6.sin6_addr),
	347	&sin.v6.sin6_port, sizeof(sin.v6.sin6_port));
	348	size = 4+sizeof(sin.v6.sin6_addr)+sizeof(sin.v6.sin6_port);
	349	}
	350	else
7f06582c	351	#endif
7eb6c37c JH	352	{
	353	memcpy(buf+4, &sin.v4.sin_addr.s_addr, sizeof(sin.v4.sin_addr.s_addr));
	354	memcpy(buf+4+sizeof(sin.v4.sin_addr.s_addr),
	355	&sin.v4.sin_port, sizeof(sin.v4.sin_port));
	356	size = 4+sizeof(sin.v4.sin_addr.s_addr)+sizeof(sin.v4.sin_port);
	357	}
7f06582c	358	}
7eb6c37c	359
7f06582c JH	360	state = US"connect";
	361	HDEBUG(D_transport\|D_acl\|D_v)
	362	{
	363	int i;
e1d04f48	364	debug_printf_indent(" SOCKS>>");
7f06582c JH	365	for (i = 0; i<size; i++) debug_printf(" %02x", buf[i]);
	366	debug_printf("\n");
	367	}
	368	if (send(fd, buf, size, 0) < 0)
	369	goto snd_err;
7eb6c37c	370
7f06582c JH	371	/* expect conn-reply (success, local(ipver, addr, port))
7f06582c JH	372	of same length as conn-request, or non-success fail code */
7eb6c37c	373
7f06582c JH	374	if ( !fd_ready(fd, tmo-time(NULL))
	375	\|\| (size = read(fd, buf, size)) < 2
	376	)
	377	goto rcv_err;
	378	HDEBUG(D_transport\|D_acl\|D_v)
	379	{
	380	int i;
e1d04f48	381	debug_printf_indent(" SOCKS>>");
7f06582c JH	382	for (i = 0; i<size; i++) debug_printf(" %02x", buf[i]);
7f06582c JH	383	debug_printf("\n");
7eb6c37c	384	}
7f06582c JH	385	if ( buf[0] != 5
	386	\|\| buf[1] != 0
	387	)
	388	goto proxy_err;
	389
e6d2a989 JH	390	proxy_external_address = string_copy(
	391	host_ntoa(buf[3] == 4 ? AF_INET6 : AF_INET, buf+4, NULL, NULL));
	392	proxy_external_port = ntohs(((uint16_t )(buf + (buf[3] == 4 ? 20 : 8))));
	393	proxy_session = TRUE;
	394
7f06582c	395	HDEBUG(D_transport\|D_acl\|D_v)
e1d04f48	396	debug_printf_indent(" proxy farside: [%s]:%d\n", proxy_external_address, proxy_external_port);
7f06582c JH	397
7f06582c JH	398	return fd;
7eb6c37c JH	399
7eb6c37c JH	400	snd_err:
e1d04f48	401	HDEBUG(D_transport\|D_acl\|D_v) debug_printf_indent(" proxy snd_err %s: %s\n", state, strerror(errno));
7eb6c37c JH	402	return -1;
	403
	404	proxy_err:
	405	{
	406	struct socks_err * se =
	407	buf[1] > nelem(socks_errs) ? NULL : socks_errs + buf[1];
	408	HDEBUG(D_transport\|D_acl\|D_v)
e1d04f48	409	debug_printf_indent(" proxy %s: %s\n", state, se ? se->reason : US"unknown error code received");
7eb6c37c JH	410	errno = se ? se->errcode : EPROTO;
	411	}
	412
	413	rcv_err:
e1d04f48	414	HDEBUG(D_transport\|D_acl\|D_v) debug_printf_indent(" proxy rcv_err %s: %s\n", state, strerror(errno));
7eb6c37c JH	415	if (!errno) errno = EPROTO;
	416	else if (errno == ENOENT) errno = ECONNABORTED;
	417	return -1;
	418	}
	419
	420	#endif /* entire file */
	421	/* vi: aw ai sw=2
	422	*/