diff options
Diffstat (limited to '3rdparty/libuv/samples/socks5-proxy/client.c')
-rw-r--r-- | 3rdparty/libuv/samples/socks5-proxy/client.c | 737 |
1 files changed, 0 insertions, 737 deletions
diff --git a/3rdparty/libuv/samples/socks5-proxy/client.c b/3rdparty/libuv/samples/socks5-proxy/client.c deleted file mode 100644 index ae9913a1c6e..00000000000 --- a/3rdparty/libuv/samples/socks5-proxy/client.c +++ /dev/null @@ -1,737 +0,0 @@ -/* Copyright StrongLoop, Inc. All rights reserved. - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to - * deal in the Software without restriction, including without limitation the - * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or - * sell copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING - * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS - * IN THE SOFTWARE. - */ - -#include "defs.h" -#include <errno.h> -#include <stdlib.h> -#include <string.h> - -/* A connection is modeled as an abstraction on top of two simple state - * machines, one for reading and one for writing. Either state machine - * is, when active, in one of three states: busy, done or stop; the fourth - * and final state, dead, is an end state and only relevant when shutting - * down the connection. A short overview: - * - * busy done stop - * ----------|---------------------------|--------------------|------| - * readable | waiting for incoming data | have incoming data | idle | - * writable | busy writing out data | completed write | idle | - * - * We could remove the done state from the writable state machine. For our - * purposes, it's functionally equivalent to the stop state. - * - * When the connection with upstream has been established, the client_ctx - * moves into a state where incoming data from the client is sent upstream - * and vice versa, incoming data from upstream is sent to the client. In - * other words, we're just piping data back and forth. See conn_cycle() - * for details. - * - * An interesting deviation from libuv's I/O model is that reads are discrete - * rather than continuous events. In layman's terms, when a read operation - * completes, the connection stops reading until further notice. - * - * The rationale for this approach is that we have to wait until the data - * has been sent out again before we can reuse the read buffer. - * - * It also pleasingly unifies with the request model that libuv uses for - * writes and everything else; libuv may switch to a request model for - * reads in the future. - */ -enum conn_state { - c_busy, /* Busy; waiting for incoming data or for a write to complete. */ - c_done, /* Done; read incoming data or write finished. */ - c_stop, /* Stopped. */ - c_dead -}; - -/* Session states. */ -enum sess_state { - s_handshake, /* Wait for client handshake. */ - s_handshake_auth, /* Wait for client authentication data. */ - s_req_start, /* Start waiting for request data. */ - s_req_parse, /* Wait for request data. */ - s_req_lookup, /* Wait for upstream hostname DNS lookup to complete. */ - s_req_connect, /* Wait for uv_tcp_connect() to complete. */ - s_proxy_start, /* Connected. Start piping data. */ - s_proxy, /* Connected. Pipe data back and forth. */ - s_kill, /* Tear down session. */ - s_almost_dead_0, /* Waiting for finalizers to complete. */ - s_almost_dead_1, /* Waiting for finalizers to complete. */ - s_almost_dead_2, /* Waiting for finalizers to complete. */ - s_almost_dead_3, /* Waiting for finalizers to complete. */ - s_almost_dead_4, /* Waiting for finalizers to complete. */ - s_dead /* Dead. Safe to free now. */ -}; - -static void do_next(client_ctx *cx); -static int do_handshake(client_ctx *cx); -static int do_handshake_auth(client_ctx *cx); -static int do_req_start(client_ctx *cx); -static int do_req_parse(client_ctx *cx); -static int do_req_lookup(client_ctx *cx); -static int do_req_connect_start(client_ctx *cx); -static int do_req_connect(client_ctx *cx); -static int do_proxy_start(client_ctx *cx); -static int do_proxy(client_ctx *cx); -static int do_kill(client_ctx *cx); -static int do_almost_dead(client_ctx *cx); -static int conn_cycle(const char *who, conn *a, conn *b); -static void conn_timer_reset(conn *c); -static void conn_timer_expire(uv_timer_t *handle, int status); -static void conn_getaddrinfo(conn *c, const char *hostname); -static void conn_getaddrinfo_done(uv_getaddrinfo_t *req, - int status, - struct addrinfo *ai); -static int conn_connect(conn *c); -static void conn_connect_done(uv_connect_t *req, int status); -static void conn_read(conn *c); -static void conn_read_done(uv_stream_t *handle, - ssize_t nread, - const uv_buf_t *buf); -static void conn_alloc(uv_handle_t *handle, size_t size, uv_buf_t *buf); -static void conn_write(conn *c, const void *data, unsigned int len); -static void conn_write_done(uv_write_t *req, int status); -static void conn_close(conn *c); -static void conn_close_done(uv_handle_t *handle); - -/* |incoming| has been initialized by server.c when this is called. */ -void client_finish_init(server_ctx *sx, client_ctx *cx) { - conn *incoming; - conn *outgoing; - - cx->sx = sx; - cx->state = s_handshake; - s5_init(&cx->parser); - - incoming = &cx->incoming; - incoming->client = cx; - incoming->result = 0; - incoming->rdstate = c_stop; - incoming->wrstate = c_stop; - incoming->idle_timeout = sx->idle_timeout; - CHECK(0 == uv_timer_init(sx->loop, &incoming->timer_handle)); - - outgoing = &cx->outgoing; - outgoing->client = cx; - outgoing->result = 0; - outgoing->rdstate = c_stop; - outgoing->wrstate = c_stop; - outgoing->idle_timeout = sx->idle_timeout; - CHECK(0 == uv_tcp_init(cx->sx->loop, &outgoing->handle.tcp)); - CHECK(0 == uv_timer_init(cx->sx->loop, &outgoing->timer_handle)); - - /* Wait for the initial packet. */ - conn_read(incoming); -} - -/* This is the core state machine that drives the client <-> upstream proxy. - * We move through the initial handshake and authentication steps first and - * end up (if all goes well) in the proxy state where we're just proxying - * data between the client and upstream. - */ -static void do_next(client_ctx *cx) { - int new_state; - - ASSERT(cx->state != s_dead); - switch (cx->state) { - case s_handshake: - new_state = do_handshake(cx); - break; - case s_handshake_auth: - new_state = do_handshake_auth(cx); - break; - case s_req_start: - new_state = do_req_start(cx); - break; - case s_req_parse: - new_state = do_req_parse(cx); - break; - case s_req_lookup: - new_state = do_req_lookup(cx); - break; - case s_req_connect: - new_state = do_req_connect(cx); - break; - case s_proxy_start: - new_state = do_proxy_start(cx); - break; - case s_proxy: - new_state = do_proxy(cx); - break; - case s_kill: - new_state = do_kill(cx); - break; - case s_almost_dead_0: - case s_almost_dead_1: - case s_almost_dead_2: - case s_almost_dead_3: - case s_almost_dead_4: - new_state = do_almost_dead(cx); - break; - default: - UNREACHABLE(); - } - cx->state = new_state; - - if (cx->state == s_dead) { - if (DEBUG_CHECKS) { - memset(cx, -1, sizeof(*cx)); - } - free(cx); - } -} - -static int do_handshake(client_ctx *cx) { - unsigned int methods; - conn *incoming; - s5_ctx *parser; - uint8_t *data; - size_t size; - int err; - - parser = &cx->parser; - incoming = &cx->incoming; - ASSERT(incoming->rdstate == c_done); - ASSERT(incoming->wrstate == c_stop); - incoming->rdstate = c_stop; - - if (incoming->result < 0) { - pr_err("read error: %s", uv_strerror(incoming->result)); - return do_kill(cx); - } - - data = (uint8_t *) incoming->t.buf; - size = (size_t) incoming->result; - err = s5_parse(parser, &data, &size); - if (err == s5_ok) { - conn_read(incoming); - return s_handshake; /* Need more data. */ - } - - if (size != 0) { - /* Could allow a round-trip saving shortcut here if the requested auth - * method is S5_AUTH_NONE (provided unauthenticated traffic is allowed.) - * Requires client support however. - */ - pr_err("junk in handshake"); - return do_kill(cx); - } - - if (err != s5_auth_select) { - pr_err("handshake error: %s", s5_strerror(err)); - return do_kill(cx); - } - - methods = s5_auth_methods(parser); - if ((methods & S5_AUTH_NONE) && can_auth_none(cx->sx, cx)) { - s5_select_auth(parser, S5_AUTH_NONE); - conn_write(incoming, "\5\0", 2); /* No auth required. */ - return s_req_start; - } - - if ((methods & S5_AUTH_PASSWD) && can_auth_passwd(cx->sx, cx)) { - /* TODO(bnoordhuis) Implement username/password auth. */ - } - - conn_write(incoming, "\5\377", 2); /* No acceptable auth. */ - return s_kill; -} - -/* TODO(bnoordhuis) Implement username/password auth. */ -static int do_handshake_auth(client_ctx *cx) { - UNREACHABLE(); - return do_kill(cx); -} - -static int do_req_start(client_ctx *cx) { - conn *incoming; - - incoming = &cx->incoming; - ASSERT(incoming->rdstate == c_stop); - ASSERT(incoming->wrstate == c_done); - incoming->wrstate = c_stop; - - if (incoming->result < 0) { - pr_err("write error: %s", uv_strerror(incoming->result)); - return do_kill(cx); - } - - conn_read(incoming); - return s_req_parse; -} - -static int do_req_parse(client_ctx *cx) { - conn *incoming; - conn *outgoing; - s5_ctx *parser; - uint8_t *data; - size_t size; - int err; - - parser = &cx->parser; - incoming = &cx->incoming; - outgoing = &cx->outgoing; - ASSERT(incoming->rdstate == c_done); - ASSERT(incoming->wrstate == c_stop); - ASSERT(outgoing->rdstate == c_stop); - ASSERT(outgoing->wrstate == c_stop); - incoming->rdstate = c_stop; - - if (incoming->result < 0) { - pr_err("read error: %s", uv_strerror(incoming->result)); - return do_kill(cx); - } - - data = (uint8_t *) incoming->t.buf; - size = (size_t) incoming->result; - err = s5_parse(parser, &data, &size); - if (err == s5_ok) { - conn_read(incoming); - return s_req_parse; /* Need more data. */ - } - - if (size != 0) { - pr_err("junk in request %u", (unsigned) size); - return do_kill(cx); - } - - if (err != s5_exec_cmd) { - pr_err("request error: %s", s5_strerror(err)); - return do_kill(cx); - } - - if (parser->cmd == s5_cmd_tcp_bind) { - /* Not supported but relatively straightforward to implement. */ - pr_warn("BIND requests are not supported."); - return do_kill(cx); - } - - if (parser->cmd == s5_cmd_udp_assoc) { - /* Not supported. Might be hard to implement because libuv has no - * functionality for detecting the MTU size which the RFC mandates. - */ - pr_warn("UDP ASSOC requests are not supported."); - return do_kill(cx); - } - ASSERT(parser->cmd == s5_cmd_tcp_connect); - - if (parser->atyp == s5_atyp_host) { - conn_getaddrinfo(outgoing, (const char *) parser->daddr); - return s_req_lookup; - } - - if (parser->atyp == s5_atyp_ipv4) { - memset(&outgoing->t.addr4, 0, sizeof(outgoing->t.addr4)); - outgoing->t.addr4.sin_family = AF_INET; - outgoing->t.addr4.sin_port = htons(parser->dport); - memcpy(&outgoing->t.addr4.sin_addr, - parser->daddr, - sizeof(outgoing->t.addr4.sin_addr)); - } else if (parser->atyp == s5_atyp_ipv6) { - memset(&outgoing->t.addr6, 0, sizeof(outgoing->t.addr6)); - outgoing->t.addr6.sin6_family = AF_INET6; - outgoing->t.addr6.sin6_port = htons(parser->dport); - memcpy(&outgoing->t.addr6.sin6_addr, - parser->daddr, - sizeof(outgoing->t.addr6.sin6_addr)); - } else { - UNREACHABLE(); - } - - return do_req_connect_start(cx); -} - -static int do_req_lookup(client_ctx *cx) { - s5_ctx *parser; - conn *incoming; - conn *outgoing; - - parser = &cx->parser; - incoming = &cx->incoming; - outgoing = &cx->outgoing; - ASSERT(incoming->rdstate == c_stop); - ASSERT(incoming->wrstate == c_stop); - ASSERT(outgoing->rdstate == c_stop); - ASSERT(outgoing->wrstate == c_stop); - - if (outgoing->result < 0) { - /* TODO(bnoordhuis) Escape control characters in parser->daddr. */ - pr_err("lookup error for \"%s\": %s", - parser->daddr, - uv_strerror(outgoing->result)); - /* Send back a 'Host unreachable' reply. */ - conn_write(incoming, "\5\4\0\1\0\0\0\0\0\0", 10); - return s_kill; - } - - /* Don't make assumptions about the offset of sin_port/sin6_port. */ - switch (outgoing->t.addr.sa_family) { - case AF_INET: - outgoing->t.addr4.sin_port = htons(parser->dport); - break; - case AF_INET6: - outgoing->t.addr6.sin6_port = htons(parser->dport); - break; - default: - UNREACHABLE(); - } - - return do_req_connect_start(cx); -} - -/* Assumes that cx->outgoing.t.sa contains a valid AF_INET/AF_INET6 address. */ -static int do_req_connect_start(client_ctx *cx) { - conn *incoming; - conn *outgoing; - int err; - - incoming = &cx->incoming; - outgoing = &cx->outgoing; - ASSERT(incoming->rdstate == c_stop); - ASSERT(incoming->wrstate == c_stop); - ASSERT(outgoing->rdstate == c_stop); - ASSERT(outgoing->wrstate == c_stop); - - if (!can_access(cx->sx, cx, &outgoing->t.addr)) { - pr_warn("connection not allowed by ruleset"); - /* Send a 'Connection not allowed by ruleset' reply. */ - conn_write(incoming, "\5\2\0\1\0\0\0\0\0\0", 10); - return s_kill; - } - - err = conn_connect(outgoing); - if (err != 0) { - pr_err("connect error: %s\n", uv_strerror(err)); - return do_kill(cx); - } - - return s_req_connect; -} - -static int do_req_connect(client_ctx *cx) { - const struct sockaddr_in6 *in6; - const struct sockaddr_in *in; - char addr_storage[sizeof(*in6)]; - conn *incoming; - conn *outgoing; - uint8_t *buf; - int addrlen; - - incoming = &cx->incoming; - outgoing = &cx->outgoing; - ASSERT(incoming->rdstate == c_stop); - ASSERT(incoming->wrstate == c_stop); - ASSERT(outgoing->rdstate == c_stop); - ASSERT(outgoing->wrstate == c_stop); - - /* Build and send the reply. Not very pretty but gets the job done. */ - buf = (uint8_t *) incoming->t.buf; - if (outgoing->result == 0) { - /* The RFC mandates that the SOCKS server must include the local port - * and address in the reply. So that's what we do. - */ - addrlen = sizeof(addr_storage); - CHECK(0 == uv_tcp_getsockname(&outgoing->handle.tcp, - (struct sockaddr *) addr_storage, - &addrlen)); - buf[0] = 5; /* Version. */ - buf[1] = 0; /* Success. */ - buf[2] = 0; /* Reserved. */ - if (addrlen == sizeof(*in)) { - buf[3] = 1; /* IPv4. */ - in = (const struct sockaddr_in *) &addr_storage; - memcpy(buf + 4, &in->sin_addr, 4); - memcpy(buf + 8, &in->sin_port, 2); - conn_write(incoming, buf, 10); - } else if (addrlen == sizeof(*in6)) { - buf[3] = 4; /* IPv6. */ - in6 = (const struct sockaddr_in6 *) &addr_storage; - memcpy(buf + 4, &in6->sin6_addr, 16); - memcpy(buf + 20, &in6->sin6_port, 2); - conn_write(incoming, buf, 22); - } else { - UNREACHABLE(); - } - return s_proxy_start; - } else { - pr_err("upstream connection error: %s\n", uv_strerror(outgoing->result)); - /* Send a 'Connection refused' reply. */ - conn_write(incoming, "\5\5\0\1\0\0\0\0\0\0", 10); - return s_kill; - } - - UNREACHABLE(); - return s_kill; -} - -static int do_proxy_start(client_ctx *cx) { - conn *incoming; - conn *outgoing; - - incoming = &cx->incoming; - outgoing = &cx->outgoing; - ASSERT(incoming->rdstate == c_stop); - ASSERT(incoming->wrstate == c_done); - ASSERT(outgoing->rdstate == c_stop); - ASSERT(outgoing->wrstate == c_stop); - incoming->wrstate = c_stop; - - if (incoming->result < 0) { - pr_err("write error: %s", uv_strerror(incoming->result)); - return do_kill(cx); - } - - conn_read(incoming); - conn_read(outgoing); - return s_proxy; -} - -/* Proxy incoming data back and forth. */ -static int do_proxy(client_ctx *cx) { - if (conn_cycle("client", &cx->incoming, &cx->outgoing)) { - return do_kill(cx); - } - - if (conn_cycle("upstream", &cx->outgoing, &cx->incoming)) { - return do_kill(cx); - } - - return s_proxy; -} - -static int do_kill(client_ctx *cx) { - int new_state; - - if (cx->state >= s_almost_dead_0) { - return cx->state; - } - - /* Try to cancel the request. The callback still runs but if the - * cancellation succeeded, it gets called with status=UV_ECANCELED. - */ - new_state = s_almost_dead_1; - if (cx->state == s_req_lookup) { - new_state = s_almost_dead_0; - uv_cancel(&cx->outgoing.t.req); - } - - conn_close(&cx->incoming); - conn_close(&cx->outgoing); - return new_state; -} - -static int do_almost_dead(client_ctx *cx) { - ASSERT(cx->state >= s_almost_dead_0); - return cx->state + 1; /* Another finalizer completed. */ -} - -static int conn_cycle(const char *who, conn *a, conn *b) { - if (a->result < 0) { - if (a->result != UV_EOF) { - pr_err("%s error: %s", who, uv_strerror(a->result)); - } - return -1; - } - - if (b->result < 0) { - return -1; - } - - if (a->wrstate == c_done) { - a->wrstate = c_stop; - } - - /* The logic is as follows: read when we don't write and write when we don't - * read. That gives us back-pressure handling for free because if the peer - * sends data faster than we consume it, TCP congestion control kicks in. - */ - if (a->wrstate == c_stop) { - if (b->rdstate == c_stop) { - conn_read(b); - } else if (b->rdstate == c_done) { - conn_write(a, b->t.buf, b->result); - b->rdstate = c_stop; /* Triggers the call to conn_read() above. */ - } - } - - return 0; -} - -static void conn_timer_reset(conn *c) { - CHECK(0 == uv_timer_start(&c->timer_handle, - conn_timer_expire, - c->idle_timeout, - 0)); -} - -static void conn_timer_expire(uv_timer_t *handle, int status) { - conn *c; - - CHECK(0 == status); - c = CONTAINER_OF(handle, conn, timer_handle); - c->result = UV_ETIMEDOUT; - do_next(c->client); -} - -static void conn_getaddrinfo(conn *c, const char *hostname) { - struct addrinfo hints; - - memset(&hints, 0, sizeof(hints)); - hints.ai_family = AF_UNSPEC; - hints.ai_socktype = SOCK_STREAM; - hints.ai_protocol = IPPROTO_TCP; - CHECK(0 == uv_getaddrinfo(c->client->sx->loop, - &c->t.addrinfo_req, - conn_getaddrinfo_done, - hostname, - NULL, - &hints)); - conn_timer_reset(c); -} - -static void conn_getaddrinfo_done(uv_getaddrinfo_t *req, - int status, - struct addrinfo *ai) { - conn *c; - - c = CONTAINER_OF(req, conn, t.addrinfo_req); - c->result = status; - - if (status == 0) { - /* FIXME(bnoordhuis) Should try all addresses. */ - if (ai->ai_family == AF_INET) { - c->t.addr4 = *(const struct sockaddr_in *) ai->ai_addr; - } else if (ai->ai_family == AF_INET6) { - c->t.addr6 = *(const struct sockaddr_in6 *) ai->ai_addr; - } else { - UNREACHABLE(); - } - } - - uv_freeaddrinfo(ai); - do_next(c->client); -} - -/* Assumes that c->t.sa contains a valid AF_INET or AF_INET6 address. */ -static int conn_connect(conn *c) { - ASSERT(c->t.addr.sa_family == AF_INET || - c->t.addr.sa_family == AF_INET6); - conn_timer_reset(c); - return uv_tcp_connect(&c->t.connect_req, - &c->handle.tcp, - &c->t.addr, - conn_connect_done); -} - -static void conn_connect_done(uv_connect_t *req, int status) { - conn *c; - - if (status == UV_ECANCELED) { - return; /* Handle has been closed. */ - } - - c = CONTAINER_OF(req, conn, t.connect_req); - c->result = status; - do_next(c->client); -} - -static void conn_read(conn *c) { - ASSERT(c->rdstate == c_stop); - CHECK(0 == uv_read_start(&c->handle.stream, conn_alloc, conn_read_done)); - c->rdstate = c_busy; - conn_timer_reset(c); -} - -static void conn_read_done(uv_stream_t *handle, - ssize_t nread, - const uv_buf_t *buf) { - conn *c; - - c = CONTAINER_OF(handle, conn, handle); - ASSERT(c->t.buf == buf->base); - ASSERT(c->rdstate == c_busy); - c->rdstate = c_done; - c->result = nread; - - uv_read_stop(&c->handle.stream); - do_next(c->client); -} - -static void conn_alloc(uv_handle_t *handle, size_t size, uv_buf_t *buf) { - conn *c; - - c = CONTAINER_OF(handle, conn, handle); - ASSERT(c->rdstate == c_busy); - buf->base = c->t.buf; - buf->len = sizeof(c->t.buf); -} - -static void conn_write(conn *c, const void *data, unsigned int len) { - uv_buf_t buf; - - ASSERT(c->wrstate == c_stop || c->wrstate == c_done); - c->wrstate = c_busy; - - /* It's okay to cast away constness here, uv_write() won't modify the - * memory. - */ - buf.base = (char *) data; - buf.len = len; - - CHECK(0 == uv_write(&c->write_req, - &c->handle.stream, - &buf, - 1, - conn_write_done)); - conn_timer_reset(c); -} - -static void conn_write_done(uv_write_t *req, int status) { - conn *c; - - if (status == UV_ECANCELED) { - return; /* Handle has been closed. */ - } - - c = CONTAINER_OF(req, conn, write_req); - ASSERT(c->wrstate == c_busy); - c->wrstate = c_done; - c->result = status; - do_next(c->client); -} - -static void conn_close(conn *c) { - ASSERT(c->rdstate != c_dead); - ASSERT(c->wrstate != c_dead); - c->rdstate = c_dead; - c->wrstate = c_dead; - c->timer_handle.data = c; - c->handle.handle.data = c; - uv_close(&c->handle.handle, conn_close_done); - uv_close((uv_handle_t *) &c->timer_handle, conn_close_done); -} - -static void conn_close_done(uv_handle_t *handle) { - conn *c; - - c = handle->data; - do_next(c->client); -} |