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

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

/* Copyright (c) Jeremy Harris 2015 - 2018 */
/* 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)
{
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(CCS opt + 4);
else if (Ustrncmp(opt, "pri=", 4) == 0)
  sob->priority = atoi(CCS opt + 4);
else if (Ustrncmp(opt, "weight=", 7) == 0)
  sob->weight = atoi(CCS 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
f9ba5e22	5	/* Copyright (c) Jeremy Harris 2015 - 2018 */
7eb6c37c JH	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	{
7eb6c37c JH	77	if (Ustrncmp(opt, "auth=", 5) == 0)
	78	{
	79	opt += 5;
	80	if (Ustrcmp(opt, "none") == 0) sob->auth_type = AUTH_NONE;
	81	else if (Ustrcmp(opt, "name") == 0) sob->auth_type = AUTH_NAME;
	82	}
	83	else if (Ustrncmp(opt, "name=", 5) == 0)
	84	sob->auth_name = opt + 5;
	85	else if (Ustrncmp(opt, "pass=", 5) == 0)
	86	sob->auth_pwd = opt + 5;
	87	else if (Ustrncmp(opt, "port=", 5) == 0)
	88	sob->port = atoi(opt + 5);
	89	else if (Ustrncmp(opt, "tmo=", 4) == 0)
2b01e535	90	sob->timeout = atoi(CCS opt + 4);
7f06582c	91	else if (Ustrncmp(opt, "pri=", 4) == 0)
2b01e535	92	sob->priority = atoi(CCS opt + 4);
7f06582c	93	else if (Ustrncmp(opt, "weight=", 7) == 0)
2b01e535	94	sob->weight = atoi(CCS opt + 7);
7eb6c37c JH	95	return;
	96	}
	97
	98	static int
	99	socks_auth(int fd, int method, socks_opts * sob, time_t tmo)
	100	{
	101	uschar * s;
	102	int len, i, j;
	103
	104	switch(method)
	105	{
	106	default:
	107	log_write(0, LOG_MAIN\|LOG_PANIC,
	108	"Unrecognised socks auth method %d", method);
	109	return FAIL;
	110	case AUTH_NONE:
	111	return OK;
	112	case AUTH_NAME:
e1d04f48	113	HDEBUG(D_transport\|D_acl\|D_v) debug_printf_indent(" socks auth NAME '%s' '%s'\n",
7eb6c37c JH	114	sob->auth_name, sob->auth_pwd);
	115	i = Ustrlen(sob->auth_name);
	116	j = Ustrlen(sob->auth_pwd);
	117	s = string_sprintf("%c%c%.255s%c%.255s", AUTH_NAME_VER,
	118	i, sob->auth_name, j, sob->auth_pwd);
	119	len = i + j + 3;
	120	HDEBUG(D_transport\|D_acl\|D_v)
	121	{
	122	int i;
e1d04f48	123	debug_printf_indent(" SOCKS>>");
7eb6c37c JH	124	for (i = 0; i<len; i++) debug_printf(" %02x", s[i]);
	125	debug_printf("\n");
	126	}
1ccd5f67 JH	127	if (send(fd, s, len, 0) < 0)
	128	return FAIL;
	129	#ifdef TCP_QUICKACK
	130	(void) setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
	131	#endif
	132	if (!fd_ready(fd, tmo-time(NULL)) \|\| read(fd, s, 2) != 2)
7eb6c37c JH	133	return FAIL;
7eb6c37c JH	134	HDEBUG(D_transport\|D_acl\|D_v)
e1d04f48	135	debug_printf_indent(" SOCKS<< %02x %02x\n", s[0], s[1]);
7eb6c37c JH	136	if (s[0] == AUTH_NAME_VER && s[1] == 0)
7eb6c37c JH	137	{
e1d04f48	138	HDEBUG(D_transport\|D_acl\|D_v) debug_printf_indent(" socks auth OK\n");
7eb6c37c JH	139	return OK;
	140	}
	141
	142	log_write(0, LOG_MAIN\|LOG_PANIC, "socks auth failed");
	143	errno = EPROTO;
	144	return FAIL;
	145	}
	146	}
	147
	148
	149
7f06582c JH	150	/* Find a suitable proxy to use from the list.
	151	Possible common code with spamd_get_server() ?
	152
	153	Return: index into proxy spec array, or -1
	154	*/
	155
	156	static int
	157	socks_get_proxy(socks_opts * proxies, unsigned nproxies)
	158	{
	159	unsigned int i;
	160	socks_opts * sd;
	161	socks_opts * lim = &proxies[nproxies];
	162	long rnd, weights;
	163	unsigned pri;
	164	static BOOL srandomed = FALSE;
	165
	166	if (nproxies == 1) /* shortcut, if we have only 1 server */
	167	return (proxies[0].is_failed ? -1 : 0);
	168
	169	/* init random */
	170	if (!srandomed)
	171	{
	172	struct timeval tv;
	173	gettimeofday(&tv, NULL);
	174	srandom((unsigned int)(tv.tv_usec/1000));
	175	srandomed = TRUE;
	176	}
	177
	178	/* scan for highest pri */
	179	for (pri = 0, sd = proxies; sd < lim; sd++)
	180	if (!sd->is_failed && sd->priority > pri)
	181	pri = sd->priority;
	182
	183	/* get sum of weights at this pri */
	184	for (weights = 0, sd = proxies; sd < lim; sd++)
	185	if (!sd->is_failed && sd->priority == pri)
	186	weights += sd->weight;
	187	if (weights == 0) /* all servers failed */
	188	return -1;
	189
	190	for (rnd = random() % weights, i = 0; i < nproxies; i++)
	191	{
	192	sd = &proxies[i];
	193	if (!sd->is_failed && sd->priority == pri)
	194	if ((rnd -= sd->weight) <= 0)
	195	return i;
	196	}
	197
	198	log_write(0, LOG_MAIN\|LOG_PANIC,
	199	"%s unknown error (memory/cpu corruption?)", __FUNCTION__);
	200	return -1;
	201	}
	202
	203
	204
7eb6c37c JH	205	/* Make a connection via a socks proxy
	206
	207	Arguments:
	208	host smtp target host
	209	host_af address family
	210	port remote tcp port number
	211	interface local interface
	212	tb transport
	213	timeout connection timeout (zero for indefinite)
	214
	215	Return value:
	216	0 on success; -1 on failure, with errno set
	217	*/
	218
	219	int
	220	socks_sock_connect(host_item * host, int host_af, int port, uschar * interface,
	221	transport_instance * tb, int timeout)
7eb6c37c JH	222	{
	223	smtp_transport_options_block * ob =
	224	(smtp_transport_options_block *)tb->options_block;
	225	const uschar * proxy_list;
	226	const uschar * proxy_spec;
	227	int sep = 0;
	228	int fd;
	229	time_t tmo;
	230	const uschar * state;
	231	uschar buf[24];
7f06582c JH	232	socks_opts proxies[32]; /* max #proxies handled */
	233	unsigned nproxies;
	234	socks_opts * sob;
	235	unsigned size;
0ab63f3d	236	blob early_data;
7eb6c37c JH	237
	238	if (!timeout) timeout = 246060; /* use 1 day for "indefinite" */
	239	tmo = time(NULL) + timeout;
	240
	241	if (!(proxy_list = expand_string(ob->socks_proxy)))
	242	{
	243	log_write(0, LOG_MAIN\|LOG_PANIC, "Bad expansion for socks_proxy in %s",
	244	tb->name);
	245	return -1;
	246	}
	247
7f06582c JH	248	/* Read proxy list */
	249
	250	for (nproxies = 0;
	251	nproxies < nelem(proxies)
	252	&& (proxy_spec = string_nextinlist(&proxy_list, &sep, NULL, 0));
	253	nproxies++)
7eb6c37c	254	{
7eb6c37c	255	int subsep = -' ';
7eb6c37c JH	256	const uschar * option;
7eb6c37c JH	257
7f06582c JH	258	socks_option_defaults(sob = &proxies[nproxies]);
	259
	260	if (!(sob->proxy_host = string_nextinlist(&proxy_spec, &subsep, NULL, 0)))
7eb6c37c JH	261	{
	262	/* paniclog config error */
	263	return -1;
	264	}
	265
	266	/XXX consider global options eg. "hide socks_password = wibble" on the tpt /
7eb6c37c JH	267	/* extract any further per-proxy options */
7eb6c37c JH	268	while ((option = string_nextinlist(&proxy_spec, &subsep, NULL, 0)))
7f06582c JH	269	socks_option(sob, option);
	270	}
	271
0ab63f3d JH	272	/* Set up the socks protocol method-selection message,
	273	for sending on connection */
	274
	275	state = US"method select";
	276	buf[0] = 5; buf[1] = 1; buf[2] = sob->auth_type;
	277	early_data.data = buf;
	278	early_data.len = 3;
	279
7f06582c JH	280	/* Try proxies until a connection succeeds */
	281
	282	for(;;)
	283	{
	284	int idx;
	285	host_item proxy;
	286	int proxy_af;
	287
	288	if ((idx = socks_get_proxy(proxies, nproxies)) < 0)
	289	{
e1d04f48	290	HDEBUG(D_transport\|D_acl\|D_v) debug_printf_indent(" no proxies left\n");
7f06582c JH	291	errno = EBUSY;
	292	return -1;
	293	}
	294	sob = &proxies[idx];
7eb6c37c JH	295
7eb6c37c JH	296	/* bodge up a host struct for the proxy */
848214f7	297	proxy.address = proxy.name = sob->proxy_host;
7f06582c	298	proxy_af = Ustrchr(sob->proxy_host, ':') ? AF_INET6 : AF_INET;
7eb6c37c	299
7f06582c	300	if ((fd = smtp_sock_connect(&proxy, proxy_af, sob->port,
0ab63f3d	301	interface, tb, sob->timeout, &early_data)) >= 0)
e6d2a989 JH	302	{
	303	proxy_local_address = string_copy(proxy.address);
	304	proxy_local_port = sob->port;
7f06582c	305	break;
e6d2a989	306	}
7f06582c JH	307
	308	log_write(0, LOG_MAIN, "%s: %s", __FUNCTION__, strerror(errno));
	309	sob->is_failed = TRUE;
	310	}
	311
	312	/* Do the socks protocol stuff */
7f06582c	313
e1d04f48	314	HDEBUG(D_transport\|D_acl\|D_v) debug_printf_indent(" SOCKS>> 05 01 %02x\n", sob->auth_type);
7f06582c JH	315
	316	/* expect method response */
	317
1ccd5f67 JH	318	#ifdef TCP_QUICKACK
	319	(void) setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
	320	#endif
	321
7f06582c JH	322	if ( !fd_ready(fd, tmo-time(NULL))
	323	\|\| read(fd, buf, 2) != 2
	324	)
	325	goto rcv_err;
	326	HDEBUG(D_transport\|D_acl\|D_v)
e1d04f48	327	debug_printf_indent(" SOCKS<< %02x %02x\n", buf[0], buf[1]);
7f06582c JH	328	if ( buf[0] != 5
	329	\|\| socks_auth(fd, buf[1], sob, tmo) != OK
	330	)
	331	goto proxy_err;
	332
	333	{
	334	union sockaddr_46 sin;
7eb6c37c JH	335	(void) ip_addr(&sin, host_af, host->address, port);
	336
	337	/* send connect (ipver, ipaddr, port) */
7f06582c	338
7eb6c37c	339	buf[0] = 5; buf[1] = 1; buf[2] = 0; buf[3] = host_af == AF_INET6 ? 4 : 1;
7f06582c	340	#if HAVE_IPV6
7eb6c37c JH	341	if (host_af == AF_INET6)
	342	{
	343	memcpy(buf+4, &sin.v6.sin6_addr, sizeof(sin.v6.sin6_addr));
	344	memcpy(buf+4+sizeof(sin.v6.sin6_addr),
	345	&sin.v6.sin6_port, sizeof(sin.v6.sin6_port));
	346	size = 4+sizeof(sin.v6.sin6_addr)+sizeof(sin.v6.sin6_port);
	347	}
	348	else
7f06582c	349	#endif
7eb6c37c JH	350	{
	351	memcpy(buf+4, &sin.v4.sin_addr.s_addr, sizeof(sin.v4.sin_addr.s_addr));
	352	memcpy(buf+4+sizeof(sin.v4.sin_addr.s_addr),
	353	&sin.v4.sin_port, sizeof(sin.v4.sin_port));
	354	size = 4+sizeof(sin.v4.sin_addr.s_addr)+sizeof(sin.v4.sin_port);
	355	}
7f06582c	356	}
7eb6c37c	357
7f06582c JH	358	state = US"connect";
	359	HDEBUG(D_transport\|D_acl\|D_v)
	360	{
	361	int i;
e1d04f48	362	debug_printf_indent(" SOCKS>>");
7f06582c JH	363	for (i = 0; i<size; i++) debug_printf(" %02x", buf[i]);
	364	debug_printf("\n");
	365	}
	366	if (send(fd, buf, size, 0) < 0)
	367	goto snd_err;
7eb6c37c	368
7f06582c JH	369	/* expect conn-reply (success, local(ipver, addr, port))
7f06582c JH	370	of same length as conn-request, or non-success fail code */
7eb6c37c	371
7f06582c JH	372	if ( !fd_ready(fd, tmo-time(NULL))
	373	\|\| (size = read(fd, buf, size)) < 2
	374	)
	375	goto rcv_err;
	376	HDEBUG(D_transport\|D_acl\|D_v)
	377	{
	378	int i;
e1d04f48	379	debug_printf_indent(" SOCKS>>");
7f06582c JH	380	for (i = 0; i<size; i++) debug_printf(" %02x", buf[i]);
7f06582c JH	381	debug_printf("\n");
7eb6c37c	382	}
7f06582c JH	383	if ( buf[0] != 5
	384	\|\| buf[1] != 0
	385	)
	386	goto proxy_err;
	387
e6d2a989 JH	388	proxy_external_address = string_copy(
	389	host_ntoa(buf[3] == 4 ? AF_INET6 : AF_INET, buf+4, NULL, NULL));
	390	proxy_external_port = ntohs(((uint16_t )(buf + (buf[3] == 4 ? 20 : 8))));
	391	proxy_session = TRUE;
	392
7f06582c	393	HDEBUG(D_transport\|D_acl\|D_v)
e1d04f48	394	debug_printf_indent(" proxy farside: [%s]:%d\n", proxy_external_address, proxy_external_port);
7f06582c JH	395
7f06582c JH	396	return fd;
7eb6c37c JH	397
7eb6c37c JH	398	snd_err:
e1d04f48	399	HDEBUG(D_transport\|D_acl\|D_v) debug_printf_indent(" proxy snd_err %s: %s\n", state, strerror(errno));
7eb6c37c JH	400	return -1;
	401
	402	proxy_err:
	403	{
	404	struct socks_err * se =
	405	buf[1] > nelem(socks_errs) ? NULL : socks_errs + buf[1];
	406	HDEBUG(D_transport\|D_acl\|D_v)
e1d04f48	407	debug_printf_indent(" proxy %s: %s\n", state, se ? se->reason : US"unknown error code received");
7eb6c37c JH	408	errno = se ? se->errcode : EPROTO;
	409	}
	410
	411	rcv_err:
e1d04f48	412	HDEBUG(D_transport\|D_acl\|D_v) debug_printf_indent(" proxy rcv_err %s: %s\n", state, strerror(errno));
7eb6c37c JH	413	if (!errno) errno = EPROTO;
	414	else if (errno == ENOENT) errno = ECONNABORTED;
	415	return -1;
	416	}
	417
	418	#endif /* entire file */
	419	/* vi: aw ai sw=2
	420	*/