X-Git-Url: https://git.distorted.org.uk/u/mdw/putty/blobdiff_plain/aab91a3e141d0ced1568fe0c5f3f562d2549d34a..68a49acbf3f96fbbbc385620655dcb577e62c328:/proxy.c diff --git a/proxy.c b/proxy.c index 408552a4..0760e7e8 100644 --- a/proxy.c +++ b/proxy.c @@ -5,7 +5,9 @@ * code and the higher level backend. */ -#include +#include +#include +#include #define DEFINE_PLUG_METHOD_MACROS #include "putty.h" @@ -20,43 +22,50 @@ void proxy_activate (Proxy_Socket p) { void *data; int len; - + long output_before, output_after; + p->state = PROXY_STATE_ACTIVE; - /* let's try to keep extra receive events from coming through */ + /* we want to ignore new receive events until we have sent + * all of our buffered receive data. + */ sk_set_frozen(p->sub_socket, 1); + /* how many bytes of output have we buffered? */ + output_before = bufchain_size(&p->pending_oob_output_data) + + bufchain_size(&p->pending_output_data); + /* and keep track of how many bytes do not get sent. */ + output_after = 0; + /* send buffered OOB writes */ while (bufchain_size(&p->pending_oob_output_data) > 0) { bufchain_prefix(&p->pending_oob_output_data, &data, &len); - sk_write_oob(p->sub_socket, data, len); + output_after += sk_write_oob(p->sub_socket, data, len); bufchain_consume(&p->pending_oob_output_data, len); } - bufchain_clear(&p->pending_oob_output_data); /* send buffered normal writes */ while (bufchain_size(&p->pending_output_data) > 0) { bufchain_prefix(&p->pending_output_data, &data, &len); - sk_write(p->sub_socket, data, len); + output_after += sk_write(p->sub_socket, data, len); bufchain_consume(&p->pending_output_data, len); } - bufchain_clear(&p->pending_output_data); + + /* if we managed to send any data, let the higher levels know. */ + if (output_after < output_before) + plug_sent(p->plug, output_after); /* if we were asked to flush the output during * the proxy negotiation process, do so now. */ if (p->pending_flush) sk_flush(p->sub_socket); - /* forward buffered recv data to the backend */ - while (bufchain_size(&p->pending_input_data) > 0) { - bufchain_prefix(&p->pending_input_data, &data, &len); - plug_receive(p->plug, 0, data, len); - bufchain_consume(&p->pending_input_data, len); - } - bufchain_clear(&p->pending_input_data); - - /* now set the underlying socket to whatever freeze state they wanted */ - sk_set_frozen(p->sub_socket, p->freeze); + /* if the backend wanted the socket unfrozen, try to unfreeze. + * our set_frozen handler will flush buffered receive data before + * unfreezing the actual underlying socket. + */ + if (!p->freeze) + sk_set_frozen((Socket)p, 0); } /* basic proxy socket functions */ @@ -133,6 +142,30 @@ static void sk_proxy_set_frozen (Socket s, int is_frozen) ps->freeze = is_frozen; return; } + + /* handle any remaining buffered recv data first */ + if (bufchain_size(&ps->pending_input_data) > 0) { + ps->freeze = is_frozen; + + /* loop while we still have buffered data, and while we are + * unfrozen. the plug_receive call in the loop could result + * in a call back into this function refreezing the socket, + * so we have to check each time. + */ + while (!ps->freeze && bufchain_size(&ps->pending_input_data) > 0) { + void *data; + int len; + bufchain_prefix(&ps->pending_input_data, &data, &len); + plug_receive(ps->plug, 0, data, len); + bufchain_consume(&ps->pending_input_data, len); + } + + /* if we're still frozen, we'll have to wait for another + * call from the backend to finish unbuffering the data. + */ + if (ps->freeze) return; + } + sk_set_frozen(ps->sub_socket, is_frozen); } @@ -279,7 +312,7 @@ Socket new_connection(SockAddr addr, char *hostname, int port, int privport, int oobinline, int nodelay, Plug plug) { - static struct socket_function_table socket_fn_table = { + static const struct socket_function_table socket_fn_table = { sk_proxy_plug, sk_proxy_close, sk_proxy_write, @@ -291,7 +324,7 @@ Socket new_connection(SockAddr addr, char *hostname, sk_proxy_socket_error }; - static struct plug_function_table plug_fn_table = { + static const struct plug_function_table plug_fn_table = { plug_proxy_closing, plug_proxy_receive, plug_proxy_sent, @@ -312,13 +345,18 @@ Socket new_connection(SockAddr addr, char *hostname, ret->remote_addr = addr; ret->remote_port = port; + ret->error = NULL; + ret->pending_flush = 0; + ret->freeze = 0; + bufchain_init(&ret->pending_input_data); bufchain_init(&ret->pending_output_data); bufchain_init(&ret->pending_oob_output_data); ret->sub_socket = NULL; ret->state = PROXY_STATE_NEW; - + ret->negotiate = NULL; + if (cfg.proxy_type == PROXY_HTTP) { ret->negotiate = proxy_http_negotiate; } else if (cfg.proxy_type == PROXY_SOCKS) { @@ -329,7 +367,7 @@ Socket new_connection(SockAddr addr, char *hostname, } else if (cfg.proxy_type == PROXY_TELNET) { ret->negotiate = proxy_telnet_negotiate; } else { - ret->error = "Network error: Unknown proxy method"; + ret->error = "Proxy error: Unknown proxy method"; return (Socket) ret; } @@ -484,7 +522,7 @@ int proxy_http_negotiate (Proxy_Socket p, int change) * we'll need to parse, process, and respond to appropriately. */ - void *data; + char *data, *datap; int len; int eol; @@ -493,27 +531,45 @@ int proxy_http_negotiate (Proxy_Socket p, int change) int min_ver, maj_ver, status; /* get the status line */ - bufchain_prefix(&p->pending_input_data, &data, &len); + len = bufchain_size(&p->pending_input_data); + assert(len > 0); /* or we wouldn't be here */ + data = smalloc(len); + bufchain_fetch(&p->pending_input_data, data, len); + eol = get_line_end(data, len); - if (eol < 0) return 1; + if (eol < 0) { + sfree(data); + return 1; + } - sscanf((char *)data, "HTTP/%i.%i %i", &maj_ver, &min_ver, &status); + status = -1; + /* We can't rely on whether the %n incremented the sscanf return */ + if (sscanf((char *)data, "HTTP/%i.%i %n", + &maj_ver, &min_ver, &status) < 2 || status == -1) { + plug_closing(p->plug, "Proxy error: HTTP response was absent", + PROXY_ERROR_GENERAL, 0); + sfree(data); + return 1; + } /* remove the status line from the input buffer. */ bufchain_consume(&p->pending_input_data, eol); - - /* TODO: we need to support Proxy-Auth headers */ - - if (status < 200 || status > 299) { + if (data[status] != '2') { /* error */ - /* TODO: return a more specific error message, - * TODO: based on the status code. - */ - plug_closing(p->plug, "Network error: Error while communicating with proxy", - PROXY_ERROR_GENERAL, 0); + char buf[1024]; + data[eol] = '\0'; + while (eol > status && + (data[eol-1] == '\r' || data[eol-1] == '\n')) + data[--eol] = '\0'; + sprintf(buf, "Proxy error: %.900s", + data+status); + plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0); + sfree(data); return 1; } + sfree(data); + p->state = 2; } @@ -523,16 +579,22 @@ int proxy_http_negotiate (Proxy_Socket p, int change) * header of length 2, (ie. just "\r\n") */ - bufchain_prefix(&p->pending_input_data, &data, &len); - eol = get_line_end(data, len); + len = bufchain_size(&p->pending_input_data); + assert(len > 0); /* or we wouldn't be here */ + data = smalloc(len); + datap = data; + bufchain_fetch(&p->pending_input_data, data, len); + + eol = get_line_end(datap, len); + if (eol < 0) { + sfree(data); + return 1; + } while (eol > 2) { - /* TODO: Proxy-Auth stuff. in some cases, we will - * TODO: need to extract information from headers. - */ bufchain_consume(&p->pending_input_data, eol); - bufchain_prefix(&p->pending_input_data, &data, &len); - eol = get_line_end(data, len); + datap += eol; + eol = get_line_end(datap, len); } if (eol == 2) { @@ -541,14 +603,16 @@ int proxy_http_negotiate (Proxy_Socket p, int change) proxy_activate(p); /* proxy activate will have dealt with * whatever is left of the buffer */ + sfree(data); return 1; } + sfree(data); return 1; } } - plug_closing(p->plug, "Network error: Unexpected proxy error", + plug_closing(p->plug, "Proxy error: unexpected proxy error", PROXY_ERROR_UNEXPECTED, 0); return 1; } @@ -575,14 +639,14 @@ int proxy_socks4_negotiate (Proxy_Socket p, int change) int length; char * command; - if (sk_addrtype(p->remote_addr) != AF_INET) { - plug_closing(p->plug, "Network error: SOCKS version 4 does not support IPv6", - PROXY_ERROR_GENERAL, 0); + if (sk_addrtype(p->remote_addr) != ADDRTYPE_IPV4) { + plug_closing(p->plug, "Proxy error: SOCKS version 4 does" + " not support IPv6", PROXY_ERROR_GENERAL, 0); return 1; } length = strlen(cfg.proxy_username) + 9; - command = (char*) malloc(length); + command = (char*) smalloc(length); strcpy(command + 8, cfg.proxy_username); command[0] = 4; /* version 4 */ @@ -596,7 +660,7 @@ int proxy_socks4_negotiate (Proxy_Socket p, int change) sk_addrcopy(p->remote_addr, command + 4); sk_write(p->sub_socket, command, length); - free(command); + sfree(command); p->state = 1; return 0; @@ -650,14 +714,16 @@ int proxy_socks4_negotiate (Proxy_Socket p, int change) * dest. address (4 bytes) */ - char *data; - int len; + char data[8]; + if (bufchain_size(&p->pending_input_data) < 8) + return 1; /* not got anything yet */ + /* get the response */ - bufchain_prefix(&p->pending_input_data, &data, &len); + bufchain_fetch(&p->pending_input_data, data, 8); if (data[0] != 0) { - plug_closing(p->plug, "Network error: SOCKS proxy responded with " + plug_closing(p->plug, "Proxy error: SOCKS proxy responded with " "unexpected reply code version", PROXY_ERROR_GENERAL, 0); return 1; @@ -667,23 +733,23 @@ int proxy_socks4_negotiate (Proxy_Socket p, int change) switch (data[1]) { case 92: - plug_closing(p->plug, "Network error: SOCKS server wanted IDENTD on client", + plug_closing(p->plug, "Proxy error: SOCKS server wanted IDENTD on client", PROXY_ERROR_GENERAL, 0); break; case 93: - plug_closing(p->plug, "Network error: Username and IDENTD on client don't agree", + plug_closing(p->plug, "Proxy error: Username and IDENTD on client don't agree", PROXY_ERROR_GENERAL, 0); break; case 91: default: - plug_closing(p->plug, "Network error: Error while communicating with proxy", + plug_closing(p->plug, "Proxy error: Error while communicating with proxy", PROXY_ERROR_GENERAL, 0); break; } return 1; } - bufchain_consume(&p->pending_input_data, 2); + bufchain_consume(&p->pending_input_data, 8); /* we're done */ proxy_activate(p); @@ -693,7 +759,7 @@ int proxy_socks4_negotiate (Proxy_Socket p, int change) } } - plug_closing(p->plug, "Network error: Unexpected proxy error", + plug_closing(p->plug, "Proxy error: unexpected proxy error", PROXY_ERROR_UNEXPECTED, 0); return 1; } @@ -770,9 +836,6 @@ int proxy_socks5_negotiate (Proxy_Socket p, int change) * we'll need to parse, process, and respond to appropriately. */ - char *data; - int len; - if (p->state == 1) { /* initial response: @@ -785,12 +848,16 @@ int proxy_socks5_negotiate (Proxy_Socket p, int change) * 0x03 = CHAP * 0xff = no acceptable methods */ + char data[2]; + + if (bufchain_size(&p->pending_input_data) < 2) + return 1; /* not got anything yet */ /* get the response */ - bufchain_prefix(&p->pending_input_data, &data, &len); + bufchain_fetch(&p->pending_input_data, data, 2); if (data[0] != 5) { - plug_closing(p->plug, "Network error: Error while communicating with proxy", + plug_closing(p->plug, "Proxy error: SOCKS proxy returned unexpected version", PROXY_ERROR_GENERAL, 0); return 1; } @@ -800,8 +867,7 @@ int proxy_socks5_negotiate (Proxy_Socket p, int change) else if (data[1] == 0x02) p->state = 5; /* username/password authentication */ else if (data[1] == 0x03) p->state = 6; /* CHAP authentication */ else { - plug_closing(p->plug, "Network error: We don't support any of the SOCKS " - "server's authentication methods", + plug_closing(p->plug, "Proxy error: SOCKS proxy did not accept our authentication", PROXY_ERROR_GENERAL, 0); return 1; } @@ -816,19 +882,25 @@ int proxy_socks5_negotiate (Proxy_Socket p, int change) * 0 = succeeded * >0 = failed */ + char data[2]; + + if (bufchain_size(&p->pending_input_data) < 2) + return 1; /* not got anything yet */ /* get the response */ - bufchain_prefix(&p->pending_input_data, &data, &len); + bufchain_fetch(&p->pending_input_data, data, 2); if (data[0] != 1) { - plug_closing(p->plug, "Network error: Error while communicating with proxy", + plug_closing(p->plug, "Proxy error: SOCKS password " + "subnegotiation contained wrong version number", PROXY_ERROR_GENERAL, 0); return 1; } if (data[1] != 0) { - plug_closing(p->plug, "Network error: Proxy refused authentication", + plug_closing(p->plug, "Proxy error: SOCKS proxy refused" + " password authentication", PROXY_ERROR_GENERAL, 0); return 1; } @@ -857,7 +929,7 @@ int proxy_socks5_negotiate (Proxy_Socket p, int change) char command[22]; int len; - if (sk_addrtype(p->remote_addr) == AF_INET) { + if (sk_addrtype(p->remote_addr) == ADDRTYPE_IPV6) { len = 10; command[3] = 1; /* IPv4 */ } else { @@ -904,46 +976,72 @@ int proxy_socks5_negotiate (Proxy_Socket p, int change) * server bound address (variable) * server bound port (2 bytes) [network order] */ + char data[5]; + int len; + + /* First 5 bytes of packet are enough to tell its length. */ + if (bufchain_size(&p->pending_input_data) < 5) + return 1; /* not got anything yet */ /* get the response */ - bufchain_prefix(&p->pending_input_data, &data, &len); + bufchain_fetch(&p->pending_input_data, data, 5); if (data[0] != 5) { - plug_closing(p->plug, "Network error: Error while communicating with proxy", + plug_closing(p->plug, "Proxy error: SOCKS proxy returned wrong version number", PROXY_ERROR_GENERAL, 0); return 1; } if (data[1] != 0) { + char buf[256]; + + strcpy(buf, "Proxy error: "); switch (data[1]) { - case 1: - case 2: - case 3: - case 4: - case 5: - case 6: - case 7: - case 8: - default: - plug_closing(p->plug, "Network error: Error while communicating with proxy", - PROXY_ERROR_GENERAL, 0); + case 1: strcat(buf, "General SOCKS server failure"); break; + case 2: strcat(buf, "Connection not allowed by ruleset"); break; + case 3: strcat(buf, "Network unreachable"); break; + case 4: strcat(buf, "Host unreachable"); break; + case 5: strcat(buf, "Connection refused"); break; + case 6: strcat(buf, "TTL expired"); break; + case 7: strcat(buf, "Command not supported"); break; + case 8: strcat(buf, "Address type not supported"); break; + default: sprintf(buf+strlen(buf), + "Unrecognised SOCKS error code %d", + data[1]); break; } + plug_closing(p->plug, buf, PROXY_ERROR_GENERAL, 0); + + return 1; + } + /* + * Eat the rest of the reply packet. + */ + len = 6; /* first 4 bytes, last 2 */ + switch (data[3]) { + case 1: len += 4; break; /* IPv4 address */ + case 4: len += 16; break;/* IPv6 address */ + case 3: len += (unsigned char)data[4]; break; /* domain name */ + default: + plug_closing(p->plug, "Proxy error: SOCKS proxy returned " + "unrecognised address format", + PROXY_ERROR_GENERAL, 0); return 1; } + if (bufchain_size(&p->pending_input_data) < len) + return 1; /* not got whole reply yet */ + bufchain_consume(&p->pending_input_data, len); /* we're done */ proxy_activate(p); - /* proxy activate will have dealt with - * whatever is left of the buffer */ return 1; } if (p->state == 4) { /* TODO: Handle GSSAPI authentication */ - plug_closing(p->plug, "Network error: We don't support GSSAPI authentication", + plug_closing(p->plug, "Proxy error: We don't support GSSAPI authentication", PROXY_ERROR_GENERAL, 0); return 1; } @@ -964,7 +1062,7 @@ int proxy_socks5_negotiate (Proxy_Socket p, int change) sk_write(p->sub_socket, userpwbuf, ulen + plen + 3); p->state = 7; } else - plug_closing(p->plug, "Network error: Server chose " + plug_closing(p->plug, "Proxy error: Server chose " "username/password authentication but we " "didn't offer it!", PROXY_ERROR_GENERAL, 0); @@ -973,14 +1071,14 @@ int proxy_socks5_negotiate (Proxy_Socket p, int change) if (p->state == 6) { /* TODO: Handle CHAP authentication */ - plug_closing(p->plug, "Network error: We don't support CHAP authentication", + plug_closing(p->plug, "Proxy error: We don't support CHAP authentication", PROXY_ERROR_GENERAL, 0); return 1; } } - plug_closing(p->plug, "Network error: Unexpected proxy error", + plug_closing(p->plug, "Proxy error: Unexpected proxy error", PROXY_ERROR_UNEXPECTED, 0); return 1; } @@ -1001,7 +1099,7 @@ int proxy_telnet_negotiate (Proxy_Socket p, int change) int so = 0, eo = 0; /* we need to escape \\, \%, \r, \n, \t, \x??, \0???, - * %%, %host, and %port + * %%, %host, %port, %user, and %pass */ while (cfg.proxy_telnet_command[eo] != 0) { @@ -1109,27 +1207,40 @@ int proxy_telnet_negotiate (Proxy_Socket p, int change) } } else { - /* % escape. we recognize %%, %host, %port. anything else, - * we just send unescaped (including the %). */ + /* % escape. we recognize %%, %host, %port, %user, %pass. + * anything else, we just send unescaped (including the %). + */ if (cfg.proxy_telnet_command[eo] == '%') { sk_write(p->sub_socket, "%", 1); eo++; - } + } else if (strnicmp(cfg.proxy_telnet_command + eo, "host", 4) == 0) { char dest[64]; sk_getaddr(p->remote_addr, dest, 64); sk_write(p->sub_socket, dest, strlen(dest)); eo += 4; - } + } else if (strnicmp(cfg.proxy_telnet_command + eo, "port", 4) == 0) { char port[8]; sprintf(port, "%i", p->remote_port); sk_write(p->sub_socket, port, strlen(port)); eo += 4; - } + } + else if (strnicmp(cfg.proxy_telnet_command + eo, + "user", 4) == 0) { + sk_write(p->sub_socket, cfg.proxy_username, + strlen(cfg.proxy_username)); + eo += 4; + } + else if (strnicmp(cfg.proxy_telnet_command + eo, + "pass", 4) == 0) { + sk_write(p->sub_socket, cfg.proxy_password, + strlen(cfg.proxy_password)); + eo += 4; + } else { /* we don't escape this, so send the % now, and * don't advance eo, so that we'll consider the @@ -1194,7 +1305,7 @@ int proxy_telnet_negotiate (Proxy_Socket p, int change) return 1; } - plug_closing(p->plug, "Network error: Unexpected proxy error", + plug_closing(p->plug, "Proxy error: Unexpected proxy error", PROXY_ERROR_UNEXPECTED, 0); return 1; }