ZyklonB: add SOCKS 5/4a support
This commit is contained in:
parent
3afd81df9b
commit
bd0187a825
455
zyklonb.c
455
zyklonb.c
@ -22,6 +22,7 @@
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#define PROGRAM_VERSION "alpha"
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#include "common.c"
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#include <arpa/inet.h>
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// --- Configuration (application-specific) ------------------------------------
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@ -39,6 +40,11 @@ static struct config_item g_config_table[] =
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{ "reconnect", "on", "Whether to reconnect on error" },
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{ "reconnect_delay", "5", "Time between reconnecting" },
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{ "socks_host", NULL, "Address of a SOCKS 4a/5 proxy" },
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{ "socks_port", "1080", "SOCKS port number" },
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{ "socks_username", NULL, "SOCKS auth. username" },
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{ "socks_password", NULL, "SOCKS auth. password" },
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{ "prefix", ":", "The prefix for bot commands" },
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{ "admin", NULL, "Host mask for administrators" },
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{ "plugins", NULL, "The plugins to load on startup" },
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@ -313,7 +319,7 @@ error_ssl_1:
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static bool
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irc_establish_connection (struct bot_context *ctx,
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const char *host, const char *port, bool use_ssl, struct error **e)
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const char *host, const char *port, struct error **e)
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{
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struct addrinfo gai_hints, *gai_result, *gai_iter;
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memset (&gai_hints, 0, sizeof gai_hints);
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@ -374,14 +380,6 @@ irc_establish_connection (struct bot_context *ctx,
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}
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ctx->irc_fd = sockfd;
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if (use_ssl && !irc_initialize_ssl (ctx, e))
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{
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xclose (ctx->irc_fd);
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ctx->irc_fd = -1;
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return false;
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}
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print_status ("connection established");
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return true;
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}
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@ -624,6 +622,409 @@ setup_recovery_handler (struct bot_context *ctx)
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print_error ("sigaction: %s", strerror (errno));
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}
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// --- SOCKS 5/4a (blocking implementation) ------------------------------------
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// These are awkward protocols. Note that the `username' is used differently
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// in SOCKS 4a and 5. In the former version, it is the username that you can
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// get ident'ed against. In the latter version, it forms a pair with the
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// password field and doesn't need to be an actual user on your machine.
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// TODO: make a non-blocking poller-based version of this; we need c-ares
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struct socks_addr
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{
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enum socks_addr_type
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{
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SOCKS_IPV4 = 1, ///< IPv4 address
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SOCKS_DOMAIN = 3, ///< Domain name to be resolved
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SOCKS_IPV6 = 4 ///< IPv6 address
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}
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type; ///< The type of this address
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union
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{
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uint8_t ipv4[4]; ///< IPv4 address, network octet order
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const char *domain; ///< Domain name
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uint8_t ipv6[16]; ///< IPv6 address, network octet order
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}
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data; ///< The address itself
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};
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struct socks_data
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{
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struct socks_addr address; ///< Target address
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uint16_t port; ///< Target port
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const char *username; ///< Authentication username
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const char *password; ///< Authentication password
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struct socks_addr bound_address; ///< Bound address at the server
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uint16_t bound_port; ///< Bound port at the server
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};
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static bool
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socks_get_socket (struct addrinfo *addresses, int *fd, struct error **e)
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{
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int sockfd;
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for (; addresses; addresses = addresses->ai_next)
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{
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sockfd = socket (addresses->ai_family,
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addresses->ai_socktype, addresses->ai_protocol);
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if (sockfd == -1)
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continue;
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set_cloexec (sockfd);
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int yes = 1;
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soft_assert (setsockopt (sockfd, SOL_SOCKET, SO_KEEPALIVE,
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&yes, sizeof yes) != -1);
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if (!connect (sockfd, addresses->ai_addr, addresses->ai_addrlen))
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break;
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xclose (sockfd);
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}
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if (!addresses)
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{
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error_set (e, "couldn't connect to the SOCKS server");
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return false;
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}
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*fd = sockfd;
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return true;
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}
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#define SOCKS_FAIL(...) \
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BLOCK_START \
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error_set (e, __VA_ARGS__); \
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goto fail; \
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BLOCK_END
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#define SOCKS_RECV(buf, len) \
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BLOCK_START \
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if ((n = recv (sockfd, (buf), (len), 0)) == -1) \
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SOCKS_FAIL ("%s: %s", "recv", strerror (errno)); \
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if (n != (len)) \
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SOCKS_FAIL ("%s: %s", "protocol error", "unexpected EOF"); \
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BLOCK_END
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static bool
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socks_4a_connect (struct addrinfo *addresses, struct socks_data *data,
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int *fd, struct error **e)
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{
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int sockfd;
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if (!socks_get_socket (addresses, &sockfd, e))
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return false;
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const void *dest_ipv4 = "\x00\x00\x00\x01";
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const char *dest_domain = NULL;
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char buf[INET6_ADDRSTRLEN];
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switch (data->address.type)
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{
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case SOCKS_IPV4:
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dest_ipv4 = data->address.data.ipv4;
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break;
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case SOCKS_IPV6:
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// About the best thing we can do, not sure if it works anywhere at all
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if (!inet_ntop (AF_INET6, &data->address.data.ipv6, buf, sizeof buf))
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SOCKS_FAIL ("%s: %s", "inet_ntop", strerror (errno));
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dest_domain = buf;
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break;
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case SOCKS_DOMAIN:
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dest_domain = data->address.data.domain;
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}
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struct str req;
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str_init (&req);
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str_append_c (&req, 4); // version
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str_append_c (&req, 1); // connect
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str_append_c (&req, data->port >> 8); // higher bits of port
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str_append_c (&req, data->port); // lower bits of port
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str_append_data (&req, dest_ipv4, 4); // destination address
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if (data->username)
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str_append (&req, data->username);
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str_append_c (&req, '\0');
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if (dest_domain)
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{
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str_append (&req, dest_domain);
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str_append_c (&req, '\0');
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}
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ssize_t n = send (sockfd, req.str, req.len, 0);
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str_free (&req);
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if (n == -1)
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SOCKS_FAIL ("%s: %s", "send", strerror (errno));
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uint8_t resp[8];
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SOCKS_RECV (resp, sizeof resp);
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if (resp[0] != 0)
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SOCKS_FAIL ("protocol error");
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switch (resp[1])
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{
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case 90:
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break;
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case 91:
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SOCKS_FAIL ("request rejected or failed");
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case 92:
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SOCKS_FAIL ("%s: %s", "request rejected",
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"SOCKS server cannot connect to identd on the client");
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case 93:
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SOCKS_FAIL ("%s: %s", "request rejected",
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"identd reports different user-id");
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default:
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SOCKS_FAIL ("protocol error");
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}
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*fd = sockfd;
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return true;
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fail:
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xclose (sockfd);
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return false;
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}
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#undef SOCKS_FAIL
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#define SOCKS_FAIL(...) \
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BLOCK_START \
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error_set (e, __VA_ARGS__); \
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return false; \
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BLOCK_END
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static bool
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socks_5_userpass_auth (int sockfd, struct socks_data *data, struct error **e)
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{
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size_t ulen = strlen (data->username);
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if (ulen > 255)
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ulen = 255;
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size_t plen = strlen (data->password);
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if (plen > 255)
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plen = 255;
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uint8_t req[3 + ulen + plen], *p = req;
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*p++ = 0x01; // version
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*p++ = ulen; // username length
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memcpy (p, data->username, ulen);
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p += ulen;
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*p++ = plen; // password length
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memcpy (p, data->password, plen);
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p += plen;
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ssize_t n = send (sockfd, req, p - req, 0);
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if (n == -1)
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SOCKS_FAIL ("%s: %s", "send", strerror (errno));
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uint8_t resp[2];
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SOCKS_RECV (resp, sizeof resp);
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if (resp[0] != 0x01)
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SOCKS_FAIL ("protocol error");
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if (resp[1] != 0x00)
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SOCKS_FAIL ("authentication failure");
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return true;
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}
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static bool
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socks_5_auth (int sockfd, struct socks_data *data, struct error **e)
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{
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bool can_auth = data->username && data->password;
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uint8_t hello[4];
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hello[0] = 0x05; // version
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hello[1] = 1 + can_auth; // number of authentication methods
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hello[2] = 0x00; // no authentication required
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hello[3] = 0x02; // username/password
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ssize_t n = send (sockfd, hello, 3 + can_auth, 0);
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if (n == -1)
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SOCKS_FAIL ("%s: %s", "send", strerror (errno));
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uint8_t resp[2];
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SOCKS_RECV (resp, sizeof resp);
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if (resp[0] != 0x05)
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SOCKS_FAIL ("protocol error");
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switch (resp[1])
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{
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case 0x02:
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if (!can_auth)
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SOCKS_FAIL ("protocol error");
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if (!socks_5_userpass_auth (sockfd, data, e))
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return false;
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case 0x00:
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break;
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case 0xFF:
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SOCKS_FAIL ("no acceptable authentication methods");
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default:
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SOCKS_FAIL ("protocol error");
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}
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return true;
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}
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static bool
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socks_5_send_req (int sockfd, struct socks_data *data, struct error **e)
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{
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uint8_t req[4 + 256 + 2], *p = req;
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*p++ = 0x05; // version
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*p++ = 0x01; // connect
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*p++ = 0x00; // reserved
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*p++ = data->address.type;
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switch (data->address.type)
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{
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case SOCKS_IPV4:
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memcpy (p, data->address.data.ipv4, sizeof data->address.data.ipv4);
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p += sizeof data->address.data.ipv4;
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break;
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case SOCKS_DOMAIN:
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{
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size_t dlen = strlen (data->address.data.domain);
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if (dlen > 255)
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dlen = 255;
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*p++ = dlen;
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memcpy (p, data->address.data.domain, dlen);
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p += dlen;
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break;
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}
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case SOCKS_IPV6:
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memcpy (p, data->address.data.ipv6, sizeof data->address.data.ipv6);
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p += sizeof data->address.data.ipv6;
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break;
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}
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*p++ = data->port >> 8;
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*p++ = data->port;
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if (send (sockfd, req, p - req, 0) == -1)
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SOCKS_FAIL ("%s: %s", "send", strerror (errno));
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return true;
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}
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static bool
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socks_5_process_resp (int sockfd, struct socks_data *data, struct error **e)
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{
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uint8_t resp_header[4];
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ssize_t n;
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SOCKS_RECV (resp_header, sizeof resp_header);
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if (resp_header[0] != 0x05)
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SOCKS_FAIL ("protocol error");
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switch (resp_header[1])
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{
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case 0x00:
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break;
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case 0x01: SOCKS_FAIL ("general SOCKS server failure");
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case 0x02: SOCKS_FAIL ("connection not allowed by ruleset");
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case 0x03: SOCKS_FAIL ("network unreachable");
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case 0x04: SOCKS_FAIL ("host unreachable");
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case 0x05: SOCKS_FAIL ("connection refused");
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case 0x06: SOCKS_FAIL ("TTL expired");
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case 0x07: SOCKS_FAIL ("command not supported");
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case 0x08: SOCKS_FAIL ("address type not supported");
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default: SOCKS_FAIL ("protocol error");
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}
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switch ((data->bound_address.type = resp_header[3]))
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{
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case SOCKS_IPV4:
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SOCKS_RECV (data->bound_address.data.ipv4,
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sizeof data->bound_address.data.ipv4);
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break;
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case SOCKS_IPV6:
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SOCKS_RECV (data->bound_address.data.ipv6,
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sizeof data->bound_address.data.ipv6);
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break;
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case SOCKS_DOMAIN:
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{
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uint8_t len;
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SOCKS_RECV (&len, sizeof len);
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char domain[len + 1];
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SOCKS_RECV (domain, len);
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domain[len] = '\0';
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data->bound_address.data.domain = xstrdup (domain);
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}
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default:
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SOCKS_FAIL ("protocol error");
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}
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uint16_t port;
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SOCKS_RECV (&port, sizeof port);
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data->bound_port = ntohs (port);
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return true;
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}
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#undef SOCKS_FAIL
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#undef SOCKS_RECV
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static bool
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socks_5_connect (struct addrinfo *addresses, struct socks_data *data,
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int *fd, struct error **e)
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{
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int sockfd;
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if (!socks_get_socket (addresses, &sockfd, e))
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return false;
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if (!socks_5_auth (sockfd, data, e)
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|| !socks_5_send_req (sockfd, data, e)
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|| !socks_5_process_resp (sockfd, data, e))
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{
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xclose (sockfd);
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return false;
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}
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*fd = sockfd;
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return true;
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}
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static int
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socks_connect (const char *socks_host, const char *socks_port,
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const char *host, const char *port,
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const char *username, const char *password, struct error **e)
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{
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struct addrinfo gai_hints, *gai_result;
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memset (&gai_hints, 0, sizeof gai_hints);
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gai_hints.ai_socktype = SOCK_STREAM;
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int err = getaddrinfo (socks_host, socks_port, &gai_hints, &gai_result);
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if (err)
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{
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error_set (e, "%s: %s", "getaddrinfo", gai_strerror (err));
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return false;
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}
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unsigned long port_no;
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const struct servent *serv;
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if ((serv = getservbyname (port, "tcp")))
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port_no = (uint16_t) serv->s_port;
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else if (!xstrtoul (&port_no, port, 10) || !port_no || port_no > UINT16_MAX)
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{
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error_set (e, "invalid port number");
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return false;
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}
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struct socks_data data =
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{ .username = username, .password = password, .port = port_no };
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if (inet_pton (AF_INET, host, &data.address.data.ipv4) == 1)
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data.address.type = SOCKS_IPV4;
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else if (inet_pton (AF_INET6, host, &data.address.data.ipv6) == 1)
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data.address.type = SOCKS_IPV6;
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else
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{
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data.address.type = SOCKS_DOMAIN;
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data.address.data.domain = host;
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}
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int fd;
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bool success = socks_5_connect (gai_result, &data, &fd, NULL)
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|| socks_4a_connect (gai_result, &data, &fd, e);
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freeaddrinfo (gai_result);
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if (data.bound_address.type == SOCKS_DOMAIN)
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free ((char *) data.bound_address.data.domain);
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return success ? fd : -1;
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}
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// --- Plugins -----------------------------------------------------------------
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/// The name of the special IRC command for interprocess communication
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@ -1558,12 +1959,17 @@ irc_connect (struct bot_context *ctx, struct error **e)
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const char *irc_port = str_map_find (&ctx->config, "irc_port");
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const char *ssl_use_str = str_map_find (&ctx->config, "ssl_use");
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const char *socks_host = str_map_find (&ctx->config, "socks_host");
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const char *socks_port = str_map_find (&ctx->config, "socks_port");
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const char *socks_username = str_map_find (&ctx->config, "socks_username");
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const char *socks_password = str_map_find (&ctx->config, "socks_password");
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const char *nickname = str_map_find (&ctx->config, "nickname");
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const char *username = str_map_find (&ctx->config, "username");
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const char *realname = str_map_find (&ctx->config, "realname");
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// We have a default value for these
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hard_assert (irc_port && ssl_use_str);
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hard_assert (irc_port && ssl_use_str && socks_port);
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hard_assert (nickname && username && realname);
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// TODO: again, get rid of `struct error' in here. The question is: how
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@ -1581,9 +1987,36 @@ irc_connect (struct bot_context *ctx, struct error **e)
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return false;
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}
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||||
|
||||
if (!irc_establish_connection (ctx, irc_host, irc_port, use_ssl, e))
|
||||
if (socks_host)
|
||||
{
|
||||
char *address = format_host_port_pair (irc_host, irc_port);
|
||||
char *socks_address = format_host_port_pair (socks_host, socks_port);
|
||||
print_status ("connecting to %s via %s...", address, socks_address);
|
||||
free (socks_address);
|
||||
free (address);
|
||||
|
||||
struct error *error = NULL;
|
||||
int fd = socks_connect (socks_host, socks_port, irc_host, irc_port,
|
||||
socks_username, socks_password, &error);
|
||||
if (fd == -1)
|
||||
{
|
||||
error_set (e, "%s: %s", "SOCKS connection failed", error->message);
|
||||
error_free (error);
|
||||
return false;
|
||||
}
|
||||
ctx->irc_fd = fd;
|
||||
}
|
||||
else if (!irc_establish_connection (ctx, irc_host, irc_port, e))
|
||||
return false;
|
||||
|
||||
if (use_ssl && !irc_initialize_ssl (ctx, e))
|
||||
{
|
||||
xclose (ctx->irc_fd);
|
||||
ctx->irc_fd = -1;
|
||||
return false;
|
||||
}
|
||||
print_status ("connection established");
|
||||
|
||||
// TODO: in exec try: 1/ set blocking, 2/ setsockopt() SO_LINGER,
|
||||
// (struct linger) { .l_onoff = true; .l_linger = 1 /* 1s should do */; }
|
||||
// 3/ /* O_CLOEXEC */ But only if the QUIT message proves unreliable.
|
||||
|
||||
Loading…
Reference in New Issue
Block a user