diff options
Diffstat (limited to 'src/or/buffers.c')
| -rw-r--r-- | src/or/buffers.c | 2063 |
1 files changed, 0 insertions, 2063 deletions
diff --git a/src/or/buffers.c b/src/or/buffers.c deleted file mode 100644 index 89382d1d8e..0000000000 --- a/src/or/buffers.c +++ /dev/null @@ -1,2063 +0,0 @@ -/* Copyright (c) 2001 Matej Pfajfar. - * Copyright (c) 2001-2004, Roger Dingledine. - * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2016, The Tor Project, Inc. */ -/* See LICENSE for licensing information */ - -/** - * \file buffers.c - * \brief Implements a generic buffer interface. - * - * A buf_t is a (fairly) opaque byte-oriented FIFO that can read to or flush - * from memory, sockets, file descriptors, TLS connections, or another buf_t. - * Buffers are implemented as linked lists of memory chunks. - * - * All socket-backed and TLS-based connection_t objects have a pair of - * buffers: one for incoming data, and one for outcoming data. These are fed - * and drained from functions in connection.c, trigged by events that are - * monitored in main.c. - * - * This module has basic support for reading and writing on buf_t objects. It - * also contains specialized functions for handling particular protocols - * on a buf_t backend, including SOCKS (used in connection_edge.c), Tor cells - * (used in connection_or.c and channeltls.c), HTTP (used in directory.c), and - * line-oriented communication (used in control.c). - **/ -#define BUFFERS_PRIVATE -#include "or.h" -#include "addressmap.h" -#include "buffers.h" -#include "config.h" -#include "connection_edge.h" -#include "connection_or.h" -#include "control.h" -#include "reasons.h" -#include "ext_orport.h" -#include "util.h" -#include "torlog.h" -#ifdef HAVE_UNISTD_H -#include <unistd.h> -#endif - -//#define PARANOIA - -#ifdef PARANOIA -/** Helper: If PARANOIA is defined, assert that the buffer in local variable - * <b>buf</b> is well-formed. */ -#define check() STMT_BEGIN assert_buf_ok(buf); STMT_END -#else -#define check() STMT_NIL -#endif - -/* Implementation notes: - * - * After flirting with memmove, and dallying with ring-buffers, we're finally - * getting up to speed with the 1970s and implementing buffers as a linked - * list of small chunks. Each buffer has such a list; data is removed from - * the head of the list, and added at the tail. The list is singly linked, - * and the buffer keeps a pointer to the head and the tail. - * - * Every chunk, except the tail, contains at least one byte of data. Data in - * each chunk is contiguous. - * - * When you need to treat the first N characters on a buffer as a contiguous - * string, use the buf_pullup function to make them so. Don't do this more - * than necessary. - * - * The major free Unix kernels have handled buffers like this since, like, - * forever. - */ - -static void socks_request_set_socks5_error(socks_request_t *req, - socks5_reply_status_t reason); - -static int parse_socks(const char *data, size_t datalen, socks_request_t *req, - int log_sockstype, int safe_socks, ssize_t *drain_out, - size_t *want_length_out); -static int parse_socks_client(const uint8_t *data, size_t datalen, - int state, char **reason, - ssize_t *drain_out); - -/* Chunk manipulation functions */ - -#define CHUNK_HEADER_LEN STRUCT_OFFSET(chunk_t, mem[0]) - -/* We leave this many NUL bytes at the end of the buffer. */ -#define SENTINEL_LEN 4 - -/* Header size plus NUL bytes at the end */ -#define CHUNK_OVERHEAD (CHUNK_HEADER_LEN + SENTINEL_LEN) - -/** Return the number of bytes needed to allocate a chunk to hold - * <b>memlen</b> bytes. */ -#define CHUNK_ALLOC_SIZE(memlen) (CHUNK_OVERHEAD + (memlen)) -/** Return the number of usable bytes in a chunk allocated with - * malloc(<b>memlen</b>). */ -#define CHUNK_SIZE_WITH_ALLOC(memlen) ((memlen) - CHUNK_OVERHEAD) - -#define DEBUG_SENTINEL - -#ifdef DEBUG_SENTINEL -#define DBG_S(s) s -#else -#define DBG_S(s) (void)0 -#endif - -#define CHUNK_SET_SENTINEL(chunk, alloclen) do { \ - uint8_t *a = (uint8_t*) &(chunk)->mem[(chunk)->memlen]; \ - DBG_S(uint8_t *b = &((uint8_t*)(chunk))[(alloclen)-SENTINEL_LEN]); \ - DBG_S(tor_assert(a == b)); \ - memset(a,0,SENTINEL_LEN); \ - } while (0) - -/** Return the next character in <b>chunk</b> onto which data can be appended. - * If the chunk is full, this might be off the end of chunk->mem. */ -static inline char * -CHUNK_WRITE_PTR(chunk_t *chunk) -{ - return chunk->data + chunk->datalen; -} - -/** Return the number of bytes that can be written onto <b>chunk</b> without - * running out of space. */ -static inline size_t -CHUNK_REMAINING_CAPACITY(const chunk_t *chunk) -{ - return (chunk->mem + chunk->memlen) - (chunk->data + chunk->datalen); -} - -/** Move all bytes stored in <b>chunk</b> to the front of <b>chunk</b>->mem, - * to free up space at the end. */ -static inline void -chunk_repack(chunk_t *chunk) -{ - if (chunk->datalen && chunk->data != &chunk->mem[0]) { - memmove(chunk->mem, chunk->data, chunk->datalen); - } - chunk->data = &chunk->mem[0]; -} - -/** Keep track of total size of allocated chunks for consistency asserts */ -static size_t total_bytes_allocated_in_chunks = 0; -static void -buf_chunk_free_unchecked(chunk_t *chunk) -{ - if (!chunk) - return; -#ifdef DEBUG_CHUNK_ALLOC - tor_assert(CHUNK_ALLOC_SIZE(chunk->memlen) == chunk->DBG_alloc); -#endif - tor_assert(total_bytes_allocated_in_chunks >= - CHUNK_ALLOC_SIZE(chunk->memlen)); - total_bytes_allocated_in_chunks -= CHUNK_ALLOC_SIZE(chunk->memlen); - tor_free(chunk); -} -static inline chunk_t * -chunk_new_with_alloc_size(size_t alloc) -{ - chunk_t *ch; - ch = tor_malloc(alloc); - ch->next = NULL; - ch->datalen = 0; -#ifdef DEBUG_CHUNK_ALLOC - ch->DBG_alloc = alloc; -#endif - ch->memlen = CHUNK_SIZE_WITH_ALLOC(alloc); - total_bytes_allocated_in_chunks += alloc; - ch->data = &ch->mem[0]; - CHUNK_SET_SENTINEL(ch, alloc); - return ch; -} - -/** Expand <b>chunk</b> until it can hold <b>sz</b> bytes, and return a - * new pointer to <b>chunk</b>. Old pointers are no longer valid. */ -static inline chunk_t * -chunk_grow(chunk_t *chunk, size_t sz) -{ - off_t offset; - const size_t memlen_orig = chunk->memlen; - const size_t orig_alloc = CHUNK_ALLOC_SIZE(memlen_orig); - const size_t new_alloc = CHUNK_ALLOC_SIZE(sz); - tor_assert(sz > chunk->memlen); - offset = chunk->data - chunk->mem; - chunk = tor_realloc(chunk, new_alloc); - chunk->memlen = sz; - chunk->data = chunk->mem + offset; -#ifdef DEBUG_CHUNK_ALLOC - tor_assert(chunk->DBG_alloc == orig_alloc); - chunk->DBG_alloc = new_alloc; -#endif - total_bytes_allocated_in_chunks += new_alloc - orig_alloc; - CHUNK_SET_SENTINEL(chunk, new_alloc); - return chunk; -} - -/** If a read onto the end of a chunk would be smaller than this number, then - * just start a new chunk. */ -#define MIN_READ_LEN 8 -/** Every chunk should take up at least this many bytes. */ -#define MIN_CHUNK_ALLOC 256 -/** No chunk should take up more than this many bytes. */ -#define MAX_CHUNK_ALLOC 65536 - -/** Return the allocation size we'd like to use to hold <b>target</b> - * bytes. */ -STATIC size_t -preferred_chunk_size(size_t target) -{ - tor_assert(target <= SIZE_T_CEILING - CHUNK_OVERHEAD); - if (CHUNK_ALLOC_SIZE(target) >= MAX_CHUNK_ALLOC) - return CHUNK_ALLOC_SIZE(target); - size_t sz = MIN_CHUNK_ALLOC; - while (CHUNK_SIZE_WITH_ALLOC(sz) < target) { - sz <<= 1; - } - return sz; -} - -/** Collapse data from the first N chunks from <b>buf</b> into buf->head, - * growing it as necessary, until buf->head has the first <b>bytes</b> bytes - * of data from the buffer, or until buf->head has all the data in <b>buf</b>. - */ -STATIC void -buf_pullup(buf_t *buf, size_t bytes) -{ - chunk_t *dest, *src; - size_t capacity; - if (!buf->head) - return; - - check(); - if (buf->datalen < bytes) - bytes = buf->datalen; - - capacity = bytes; - if (buf->head->datalen >= bytes) - return; - - if (buf->head->memlen >= capacity) { - /* We don't need to grow the first chunk, but we might need to repack it.*/ - size_t needed = capacity - buf->head->datalen; - if (CHUNK_REMAINING_CAPACITY(buf->head) < needed) - chunk_repack(buf->head); - tor_assert(CHUNK_REMAINING_CAPACITY(buf->head) >= needed); - } else { - chunk_t *newhead; - size_t newsize; - /* We need to grow the chunk. */ - chunk_repack(buf->head); - newsize = CHUNK_SIZE_WITH_ALLOC(preferred_chunk_size(capacity)); - newhead = chunk_grow(buf->head, newsize); - tor_assert(newhead->memlen >= capacity); - if (newhead != buf->head) { - if (buf->tail == buf->head) - buf->tail = newhead; - buf->head = newhead; - } - } - - dest = buf->head; - while (dest->datalen < bytes) { - size_t n = bytes - dest->datalen; - src = dest->next; - tor_assert(src); - if (n >= src->datalen) { - memcpy(CHUNK_WRITE_PTR(dest), src->data, src->datalen); - dest->datalen += src->datalen; - dest->next = src->next; - if (buf->tail == src) - buf->tail = dest; - buf_chunk_free_unchecked(src); - } else { - memcpy(CHUNK_WRITE_PTR(dest), src->data, n); - dest->datalen += n; - src->data += n; - src->datalen -= n; - tor_assert(dest->datalen == bytes); - } - } - - check(); -} - -#ifdef TOR_UNIT_TESTS -void -buf_get_first_chunk_data(const buf_t *buf, const char **cp, size_t *sz) -{ - if (!buf || !buf->head) { - *cp = NULL; - *sz = 0; - } else { - *cp = buf->head->data; - *sz = buf->head->datalen; - } -} -#endif - -/** Remove the first <b>n</b> bytes from buf. */ -static inline void -buf_remove_from_front(buf_t *buf, size_t n) -{ - tor_assert(buf->datalen >= n); - while (n) { - tor_assert(buf->head); - if (buf->head->datalen > n) { - buf->head->datalen -= n; - buf->head->data += n; - buf->datalen -= n; - return; - } else { - chunk_t *victim = buf->head; - n -= victim->datalen; - buf->datalen -= victim->datalen; - buf->head = victim->next; - if (buf->tail == victim) - buf->tail = NULL; - buf_chunk_free_unchecked(victim); - } - } - check(); -} - -/** Create and return a new buf with default chunk capacity <b>size</b>. - */ -buf_t * -buf_new_with_capacity(size_t size) -{ - buf_t *b = buf_new(); - b->default_chunk_size = preferred_chunk_size(size); - return b; -} - -/** Allocate and return a new buffer with default capacity. */ -buf_t * -buf_new(void) -{ - buf_t *buf = tor_malloc_zero(sizeof(buf_t)); - buf->magic = BUFFER_MAGIC; - buf->default_chunk_size = 4096; - return buf; -} - -size_t -buf_get_default_chunk_size(const buf_t *buf) -{ - return buf->default_chunk_size; -} - -/** Remove all data from <b>buf</b>. */ -void -buf_clear(buf_t *buf) -{ - chunk_t *chunk, *next; - buf->datalen = 0; - for (chunk = buf->head; chunk; chunk = next) { - next = chunk->next; - buf_chunk_free_unchecked(chunk); - } - buf->head = buf->tail = NULL; -} - -/** Return the number of bytes stored in <b>buf</b> */ -MOCK_IMPL(size_t, -buf_datalen, (const buf_t *buf)) -{ - return buf->datalen; -} - -/** Return the total length of all chunks used in <b>buf</b>. */ -size_t -buf_allocation(const buf_t *buf) -{ - size_t total = 0; - const chunk_t *chunk; - for (chunk = buf->head; chunk; chunk = chunk->next) { - total += CHUNK_ALLOC_SIZE(chunk->memlen); - } - return total; -} - -/** Return the number of bytes that can be added to <b>buf</b> without - * performing any additional allocation. */ -size_t -buf_slack(const buf_t *buf) -{ - if (!buf->tail) - return 0; - else - return CHUNK_REMAINING_CAPACITY(buf->tail); -} - -/** Release storage held by <b>buf</b>. */ -void -buf_free(buf_t *buf) -{ - if (!buf) - return; - - buf_clear(buf); - buf->magic = 0xdeadbeef; - tor_free(buf); -} - -/** Return a new copy of <b>in_chunk</b> */ -static chunk_t * -chunk_copy(const chunk_t *in_chunk) -{ - chunk_t *newch = tor_memdup(in_chunk, CHUNK_ALLOC_SIZE(in_chunk->memlen)); - total_bytes_allocated_in_chunks += CHUNK_ALLOC_SIZE(in_chunk->memlen); -#ifdef DEBUG_CHUNK_ALLOC - newch->DBG_alloc = CHUNK_ALLOC_SIZE(in_chunk->memlen); -#endif - newch->next = NULL; - if (in_chunk->data) { - off_t offset = in_chunk->data - in_chunk->mem; - newch->data = newch->mem + offset; - } - return newch; -} - -/** Return a new copy of <b>buf</b> */ -buf_t * -buf_copy(const buf_t *buf) -{ - chunk_t *ch; - buf_t *out = buf_new(); - out->default_chunk_size = buf->default_chunk_size; - for (ch = buf->head; ch; ch = ch->next) { - chunk_t *newch = chunk_copy(ch); - if (out->tail) { - out->tail->next = newch; - out->tail = newch; - } else { - out->head = out->tail = newch; - } - } - out->datalen = buf->datalen; - return out; -} - -/** Append a new chunk with enough capacity to hold <b>capacity</b> bytes to - * the tail of <b>buf</b>. If <b>capped</b>, don't allocate a chunk bigger - * than MAX_CHUNK_ALLOC. */ -static chunk_t * -buf_add_chunk_with_capacity(buf_t *buf, size_t capacity, int capped) -{ - chunk_t *chunk; - - if (CHUNK_ALLOC_SIZE(capacity) < buf->default_chunk_size) { - chunk = chunk_new_with_alloc_size(buf->default_chunk_size); - } else if (capped && CHUNK_ALLOC_SIZE(capacity) > MAX_CHUNK_ALLOC) { - chunk = chunk_new_with_alloc_size(MAX_CHUNK_ALLOC); - } else { - chunk = chunk_new_with_alloc_size(preferred_chunk_size(capacity)); - } - - chunk->inserted_time = (uint32_t)monotime_coarse_absolute_msec(); - - if (buf->tail) { - tor_assert(buf->head); - buf->tail->next = chunk; - buf->tail = chunk; - } else { - tor_assert(!buf->head); - buf->head = buf->tail = chunk; - } - check(); - return chunk; -} - -/** Return the age of the oldest chunk in the buffer <b>buf</b>, in - * milliseconds. Requires the current monotonic time, in truncated msec, - * as its input <b>now</b>. - */ -uint32_t -buf_get_oldest_chunk_timestamp(const buf_t *buf, uint32_t now) -{ - if (buf->head) { - return now - buf->head->inserted_time; - } else { - return 0; - } -} - -size_t -buf_get_total_allocation(void) -{ - return total_bytes_allocated_in_chunks; -} - -/** Read up to <b>at_most</b> bytes from the socket <b>fd</b> into - * <b>chunk</b> (which must be on <b>buf</b>). If we get an EOF, set - * *<b>reached_eof</b> to 1. Return -1 on error, 0 on eof or blocking, - * and the number of bytes read otherwise. */ -static inline int -read_to_chunk(buf_t *buf, chunk_t *chunk, tor_socket_t fd, size_t at_most, - int *reached_eof, int *socket_error) -{ - ssize_t read_result; - if (at_most > CHUNK_REMAINING_CAPACITY(chunk)) - at_most = CHUNK_REMAINING_CAPACITY(chunk); - read_result = tor_socket_recv(fd, CHUNK_WRITE_PTR(chunk), at_most, 0); - - if (read_result < 0) { - int e = tor_socket_errno(fd); - if (!ERRNO_IS_EAGAIN(e)) { /* it's a real error */ -#ifdef _WIN32 - if (e == WSAENOBUFS) - log_warn(LD_NET,"recv() failed: WSAENOBUFS. Not enough ram?"); -#endif - *socket_error = e; - return -1; - } - return 0; /* would block. */ - } else if (read_result == 0) { - log_debug(LD_NET,"Encountered eof on fd %d", (int)fd); - *reached_eof = 1; - return 0; - } else { /* actually got bytes. */ - buf->datalen += read_result; - chunk->datalen += read_result; - log_debug(LD_NET,"Read %ld bytes. %d on inbuf.", (long)read_result, - (int)buf->datalen); - tor_assert(read_result < INT_MAX); - return (int)read_result; - } -} - -/** As read_to_chunk(), but return (negative) error code on error, blocking, - * or TLS, and the number of bytes read otherwise. */ -static inline int -read_to_chunk_tls(buf_t *buf, chunk_t *chunk, tor_tls_t *tls, - size_t at_most) -{ - int read_result; - - tor_assert(CHUNK_REMAINING_CAPACITY(chunk) >= at_most); - read_result = tor_tls_read(tls, CHUNK_WRITE_PTR(chunk), at_most); - if (read_result < 0) - return read_result; - buf->datalen += read_result; - chunk->datalen += read_result; - return read_result; -} - -/** Read from socket <b>s</b>, writing onto end of <b>buf</b>. Read at most - * <b>at_most</b> bytes, growing the buffer as necessary. If recv() returns 0 - * (because of EOF), set *<b>reached_eof</b> to 1 and return 0. Return -1 on - * error; else return the number of bytes read. - */ -/* XXXX indicate "read blocked" somehow? */ -int -read_to_buf(tor_socket_t s, size_t at_most, buf_t *buf, int *reached_eof, - int *socket_error) -{ - /* XXXX It's stupid to overload the return values for these functions: - * "error status" and "number of bytes read" are not mutually exclusive. - */ - int r = 0; - size_t total_read = 0; - - check(); - tor_assert(reached_eof); - tor_assert(SOCKET_OK(s)); - - while (at_most > total_read) { - size_t readlen = at_most - total_read; - chunk_t *chunk; - if (!buf->tail || CHUNK_REMAINING_CAPACITY(buf->tail) < MIN_READ_LEN) { - chunk = buf_add_chunk_with_capacity(buf, at_most, 1); - if (readlen > chunk->memlen) - readlen = chunk->memlen; - } else { - size_t cap = CHUNK_REMAINING_CAPACITY(buf->tail); - chunk = buf->tail; - if (cap < readlen) - readlen = cap; - } - - r = read_to_chunk(buf, chunk, s, readlen, reached_eof, socket_error); - check(); - if (r < 0) - return r; /* Error */ - tor_assert(total_read+r < INT_MAX); - total_read += r; - if ((size_t)r < readlen) { /* eof, block, or no more to read. */ - break; - } - } - return (int)total_read; -} - -/** As read_to_buf, but reads from a TLS connection, and returns a TLS - * status value rather than the number of bytes read. - * - * Using TLS on OR connections complicates matters in two ways. - * - * First, a TLS stream has its own read buffer independent of the - * connection's read buffer. (TLS needs to read an entire frame from - * the network before it can decrypt any data. Thus, trying to read 1 - * byte from TLS can require that several KB be read from the network - * and decrypted. The extra data is stored in TLS's decrypt buffer.) - * Because the data hasn't been read by Tor (it's still inside the TLS), - * this means that sometimes a connection "has stuff to read" even when - * poll() didn't return POLLIN. The tor_tls_get_pending_bytes function is - * used in connection.c to detect TLS objects with non-empty internal - * buffers and read from them again. - * - * Second, the TLS stream's events do not correspond directly to network - * events: sometimes, before a TLS stream can read, the network must be - * ready to write -- or vice versa. - */ -int -read_to_buf_tls(tor_tls_t *tls, size_t at_most, buf_t *buf) -{ - int r = 0; - size_t total_read = 0; - - check_no_tls_errors(); - - check(); - - while (at_most > total_read) { - size_t readlen = at_most - total_read; - chunk_t *chunk; - if (!buf->tail || CHUNK_REMAINING_CAPACITY(buf->tail) < MIN_READ_LEN) { - chunk = buf_add_chunk_with_capacity(buf, at_most, 1); - if (readlen > chunk->memlen) - readlen = chunk->memlen; - } else { - size_t cap = CHUNK_REMAINING_CAPACITY(buf->tail); - chunk = buf->tail; - if (cap < readlen) - readlen = cap; - } - - r = read_to_chunk_tls(buf, chunk, tls, readlen); - check(); - if (r < 0) - return r; /* Error */ - tor_assert(total_read+r < INT_MAX); - total_read += r; - if ((size_t)r < readlen) /* eof, block, or no more to read. */ - break; - } - return (int)total_read; -} - -/** Helper for flush_buf(): try to write <b>sz</b> bytes from chunk - * <b>chunk</b> of buffer <b>buf</b> onto socket <b>s</b>. On success, deduct - * the bytes written from *<b>buf_flushlen</b>. Return the number of bytes - * written on success, 0 on blocking, -1 on failure. - */ -static inline int -flush_chunk(tor_socket_t s, buf_t *buf, chunk_t *chunk, size_t sz, - size_t *buf_flushlen) -{ - ssize_t write_result; - - if (sz > chunk->datalen) - sz = chunk->datalen; - write_result = tor_socket_send(s, chunk->data, sz, 0); - - if (write_result < 0) { - int e = tor_socket_errno(s); - if (!ERRNO_IS_EAGAIN(e)) { /* it's a real error */ -#ifdef _WIN32 - if (e == WSAENOBUFS) - log_warn(LD_NET,"write() failed: WSAENOBUFS. Not enough ram?"); -#endif - return -1; - } - log_debug(LD_NET,"write() would block, returning."); - return 0; - } else { - *buf_flushlen -= write_result; - buf_remove_from_front(buf, write_result); - tor_assert(write_result < INT_MAX); - return (int)write_result; - } -} - -/** Helper for flush_buf_tls(): try to write <b>sz</b> bytes from chunk - * <b>chunk</b> of buffer <b>buf</b> onto socket <b>s</b>. (Tries to write - * more if there is a forced pending write size.) On success, deduct the - * bytes written from *<b>buf_flushlen</b>. Return the number of bytes - * written on success, and a TOR_TLS error code on failure or blocking. - */ -static inline int -flush_chunk_tls(tor_tls_t *tls, buf_t *buf, chunk_t *chunk, - size_t sz, size_t *buf_flushlen) -{ - int r; - size_t forced; - char *data; - - forced = tor_tls_get_forced_write_size(tls); - if (forced > sz) - sz = forced; - if (chunk) { - data = chunk->data; - tor_assert(sz <= chunk->datalen); - } else { - data = NULL; - tor_assert(sz == 0); - } - r = tor_tls_write(tls, data, sz); - if (r < 0) - return r; - if (*buf_flushlen > (size_t)r) - *buf_flushlen -= r; - else - *buf_flushlen = 0; - buf_remove_from_front(buf, r); - log_debug(LD_NET,"flushed %d bytes, %d ready to flush, %d remain.", - r,(int)*buf_flushlen,(int)buf->datalen); - return r; -} - -/** Write data from <b>buf</b> to the socket <b>s</b>. Write at most - * <b>sz</b> bytes, decrement *<b>buf_flushlen</b> by - * the number of bytes actually written, and remove the written bytes - * from the buffer. Return the number of bytes written on success, - * -1 on failure. Return 0 if write() would block. - */ -int -flush_buf(tor_socket_t s, buf_t *buf, size_t sz, size_t *buf_flushlen) -{ - /* XXXX It's stupid to overload the return values for these functions: - * "error status" and "number of bytes flushed" are not mutually exclusive. - */ - int r; - size_t flushed = 0; - tor_assert(buf_flushlen); - tor_assert(SOCKET_OK(s)); - tor_assert(*buf_flushlen <= buf->datalen); - tor_assert(sz <= *buf_flushlen); - - check(); - while (sz) { - size_t flushlen0; - tor_assert(buf->head); - if (buf->head->datalen >= sz) - flushlen0 = sz; - else - flushlen0 = buf->head->datalen; - - r = flush_chunk(s, buf, buf->head, flushlen0, buf_flushlen); - check(); - if (r < 0) - return r; - flushed += r; - sz -= r; - if (r == 0 || (size_t)r < flushlen0) /* can't flush any more now. */ - break; - } - tor_assert(flushed < INT_MAX); - return (int)flushed; -} - -/** As flush_buf(), but writes data to a TLS connection. Can write more than - * <b>flushlen</b> bytes. - */ -int -flush_buf_tls(tor_tls_t *tls, buf_t *buf, size_t flushlen, - size_t *buf_flushlen) -{ - int r; - size_t flushed = 0; - ssize_t sz; - tor_assert(buf_flushlen); - tor_assert(*buf_flushlen <= buf->datalen); - tor_assert(flushlen <= *buf_flushlen); - sz = (ssize_t) flushlen; - - /* we want to let tls write even if flushlen is zero, because it might - * have a partial record pending */ - check_no_tls_errors(); - - check(); - do { - size_t flushlen0; - if (buf->head) { - if ((ssize_t)buf->head->datalen >= sz) - flushlen0 = sz; - else - flushlen0 = buf->head->datalen; - } else { - flushlen0 = 0; - } - - r = flush_chunk_tls(tls, buf, buf->head, flushlen0, buf_flushlen); - check(); - if (r < 0) - return r; - flushed += r; - sz -= r; - if (r == 0) /* Can't flush any more now. */ - break; - } while (sz > 0); - tor_assert(flushed < INT_MAX); - return (int)flushed; -} - -/** Append <b>string_len</b> bytes from <b>string</b> to the end of - * <b>buf</b>. - * - * Return the new length of the buffer on success, -1 on failure. - */ -int -write_to_buf(const char *string, size_t string_len, buf_t *buf) -{ - if (!string_len) - return (int)buf->datalen; - check(); - - while (string_len) { - size_t copy; - if (!buf->tail || !CHUNK_REMAINING_CAPACITY(buf->tail)) - buf_add_chunk_with_capacity(buf, string_len, 1); - - copy = CHUNK_REMAINING_CAPACITY(buf->tail); - if (copy > string_len) - copy = string_len; - memcpy(CHUNK_WRITE_PTR(buf->tail), string, copy); - string_len -= copy; - string += copy; - buf->datalen += copy; - buf->tail->datalen += copy; - } - - check(); - tor_assert(buf->datalen < INT_MAX); - return (int)buf->datalen; -} - -/** Helper: copy the first <b>string_len</b> bytes from <b>buf</b> - * onto <b>string</b>. - */ -static inline void -peek_from_buf(char *string, size_t string_len, const buf_t *buf) -{ - chunk_t *chunk; - - tor_assert(string); - /* make sure we don't ask for too much */ - tor_assert(string_len <= buf->datalen); - /* assert_buf_ok(buf); */ - - chunk = buf->head; - while (string_len) { - size_t copy = string_len; - tor_assert(chunk); - if (chunk->datalen < copy) - copy = chunk->datalen; - memcpy(string, chunk->data, copy); - string_len -= copy; - string += copy; - chunk = chunk->next; - } -} - -/** Remove <b>string_len</b> bytes from the front of <b>buf</b>, and store - * them into <b>string</b>. Return the new buffer size. <b>string_len</b> - * must be \<= the number of bytes on the buffer. - */ -int -fetch_from_buf(char *string, size_t string_len, buf_t *buf) -{ - /* There must be string_len bytes in buf; write them onto string, - * then memmove buf back (that is, remove them from buf). - * - * Return the number of bytes still on the buffer. */ - - check(); - peek_from_buf(string, string_len, buf); - buf_remove_from_front(buf, string_len); - check(); - tor_assert(buf->datalen < INT_MAX); - return (int)buf->datalen; -} - -/** True iff the cell command <b>command</b> is one that implies a - * variable-length cell in Tor link protocol <b>linkproto</b>. */ -static inline int -cell_command_is_var_length(uint8_t command, int linkproto) -{ - /* If linkproto is v2 (2), CELL_VERSIONS is the only variable-length cells - * work as implemented here. If it's 1, there are no variable-length cells. - * Tor does not support other versions right now, and so can't negotiate - * them. - */ - switch (linkproto) { - case 1: - /* Link protocol version 1 has no variable-length cells. */ - return 0; - case 2: - /* In link protocol version 2, VERSIONS is the only variable-length cell */ - return command == CELL_VERSIONS; - case 0: - case 3: - default: - /* In link protocol version 3 and later, and in version "unknown", - * commands 128 and higher indicate variable-length. VERSIONS is - * grandfathered in. */ - return command == CELL_VERSIONS || command >= 128; - } -} - -/** Check <b>buf</b> for a variable-length cell according to the rules of link - * protocol version <b>linkproto</b>. If one is found, pull it off the buffer - * and assign a newly allocated var_cell_t to *<b>out</b>, and return 1. - * Return 0 if whatever is on the start of buf_t is not a variable-length - * cell. Return 1 and set *<b>out</b> to NULL if there seems to be the start - * of a variable-length cell on <b>buf</b>, but the whole thing isn't there - * yet. */ -int -fetch_var_cell_from_buf(buf_t *buf, var_cell_t **out, int linkproto) -{ - char hdr[VAR_CELL_MAX_HEADER_SIZE]; - var_cell_t *result; - uint8_t command; - uint16_t length; - const int wide_circ_ids = linkproto >= MIN_LINK_PROTO_FOR_WIDE_CIRC_IDS; - const int circ_id_len = get_circ_id_size(wide_circ_ids); - const unsigned header_len = get_var_cell_header_size(wide_circ_ids); - check(); - *out = NULL; - if (buf->datalen < header_len) - return 0; - peek_from_buf(hdr, header_len, buf); - - command = get_uint8(hdr + circ_id_len); - if (!(cell_command_is_var_length(command, linkproto))) - return 0; - - length = ntohs(get_uint16(hdr + circ_id_len + 1)); - if (buf->datalen < (size_t)(header_len+length)) - return 1; - result = var_cell_new(length); - result->command = command; - if (wide_circ_ids) - result->circ_id = ntohl(get_uint32(hdr)); - else - result->circ_id = ntohs(get_uint16(hdr)); - - buf_remove_from_front(buf, header_len); - peek_from_buf((char*) result->payload, length, buf); - buf_remove_from_front(buf, length); - check(); - - *out = result; - return 1; -} - -/** Move up to *<b>buf_flushlen</b> bytes from <b>buf_in</b> to - * <b>buf_out</b>, and modify *<b>buf_flushlen</b> appropriately. - * Return the number of bytes actually copied. - */ -int -move_buf_to_buf(buf_t *buf_out, buf_t *buf_in, size_t *buf_flushlen) -{ - /* We can do way better here, but this doesn't turn up in any profiles. */ - char b[4096]; - size_t cp, len; - len = *buf_flushlen; - if (len > buf_in->datalen) - len = buf_in->datalen; - - cp = len; /* Remember the number of bytes we intend to copy. */ - tor_assert(cp < INT_MAX); - while (len) { - /* This isn't the most efficient implementation one could imagine, since - * it does two copies instead of 1, but I kinda doubt that this will be - * critical path. */ - size_t n = len > sizeof(b) ? sizeof(b) : len; - fetch_from_buf(b, n, buf_in); - write_to_buf(b, n, buf_out); - len -= n; - } - *buf_flushlen -= cp; - return (int)cp; -} - -/** Internal structure: represents a position in a buffer. */ -typedef struct buf_pos_t { - const chunk_t *chunk; /**< Which chunk are we pointing to? */ - int pos;/**< Which character inside the chunk's data are we pointing to? */ - size_t chunk_pos; /**< Total length of all previous chunks. */ -} buf_pos_t; - -/** Initialize <b>out</b> to point to the first character of <b>buf</b>.*/ -static void -buf_pos_init(const buf_t *buf, buf_pos_t *out) -{ - out->chunk = buf->head; - out->pos = 0; - out->chunk_pos = 0; -} - -/** Advance <b>out</b> to the first appearance of <b>ch</b> at the current - * position of <b>out</b>, or later. Return -1 if no instances are found; - * otherwise returns the absolute position of the character. */ -static off_t -buf_find_pos_of_char(char ch, buf_pos_t *out) -{ - const chunk_t *chunk; - int pos; - tor_assert(out); - if (out->chunk) { - if (out->chunk->datalen) { - tor_assert(out->pos < (off_t)out->chunk->datalen); - } else { - tor_assert(out->pos == 0); - } - } - pos = out->pos; - for (chunk = out->chunk; chunk; chunk = chunk->next) { - char *cp = memchr(chunk->data+pos, ch, chunk->datalen - pos); - if (cp) { - out->chunk = chunk; - tor_assert(cp - chunk->data < INT_MAX); - out->pos = (int)(cp - chunk->data); - return out->chunk_pos + out->pos; - } else { - out->chunk_pos += chunk->datalen; - pos = 0; - } - } - return -1; -} - -/** Advance <b>pos</b> by a single character, if there are any more characters - * in the buffer. Returns 0 on success, -1 on failure. */ -static inline int -buf_pos_inc(buf_pos_t *pos) -{ - ++pos->pos; - if (pos->pos == (off_t)pos->chunk->datalen) { - if (!pos->chunk->next) - return -1; - pos->chunk_pos += pos->chunk->datalen; - pos->chunk = pos->chunk->next; - pos->pos = 0; - } - return 0; -} - -/** Return true iff the <b>n</b>-character string in <b>s</b> appears - * (verbatim) at <b>pos</b>. */ -static int -buf_matches_at_pos(const buf_pos_t *pos, const char *s, size_t n) -{ - buf_pos_t p; - if (!n) - return 1; - - memcpy(&p, pos, sizeof(p)); - - while (1) { - char ch = p.chunk->data[p.pos]; - if (ch != *s) - return 0; - ++s; - /* If we're out of characters that don't match, we match. Check this - * _before_ we test incrementing pos, in case we're at the end of the - * string. */ - if (--n == 0) - return 1; - if (buf_pos_inc(&p)<0) - return 0; - } -} - -/** Return the first position in <b>buf</b> at which the <b>n</b>-character - * string <b>s</b> occurs, or -1 if it does not occur. */ -STATIC int -buf_find_string_offset(const buf_t *buf, const char *s, size_t n) -{ - buf_pos_t pos; - buf_pos_init(buf, &pos); - while (buf_find_pos_of_char(*s, &pos) >= 0) { - if (buf_matches_at_pos(&pos, s, n)) { - tor_assert(pos.chunk_pos + pos.pos < INT_MAX); - return (int)(pos.chunk_pos + pos.pos); - } else { - if (buf_pos_inc(&pos)<0) - return -1; - } - } - return -1; -} - -/** There is a (possibly incomplete) http statement on <b>buf</b>, of the - * form "\%s\\r\\n\\r\\n\%s", headers, body. (body may contain NULs.) - * If a) the headers include a Content-Length field and all bytes in - * the body are present, or b) there's no Content-Length field and - * all headers are present, then: - * - * - strdup headers into <b>*headers_out</b>, and NUL-terminate it. - * - memdup body into <b>*body_out</b>, and NUL-terminate it. - * - Then remove them from <b>buf</b>, and return 1. - * - * - If headers or body is NULL, discard that part of the buf. - * - If a headers or body doesn't fit in the arg, return -1. - * (We ensure that the headers or body don't exceed max len, - * _even if_ we're planning to discard them.) - * - If force_complete is true, then succeed even if not all of the - * content has arrived. - * - * Else, change nothing and return 0. - */ -int -fetch_from_buf_http(buf_t *buf, - char **headers_out, size_t max_headerlen, - char **body_out, size_t *body_used, size_t max_bodylen, - int force_complete) -{ - char *headers, *p; - size_t headerlen, bodylen, contentlen; - int crlf_offset; - - check(); - if (!buf->head) - return 0; - - crlf_offset = buf_find_string_offset(buf, "\r\n\r\n", 4); - if (crlf_offset > (int)max_headerlen || - (crlf_offset < 0 && buf->datalen > max_headerlen)) { - log_debug(LD_HTTP,"headers too long."); - return -1; - } else if (crlf_offset < 0) { - log_debug(LD_HTTP,"headers not all here yet."); - return 0; - } - /* Okay, we have a full header. Make sure it all appears in the first - * chunk. */ - if ((int)buf->head->datalen < crlf_offset + 4) - buf_pullup(buf, crlf_offset+4); - headerlen = crlf_offset + 4; - - headers = buf->head->data; - bodylen = buf->datalen - headerlen; - log_debug(LD_HTTP,"headerlen %d, bodylen %d.", (int)headerlen, (int)bodylen); - - if (max_headerlen <= headerlen) { - log_warn(LD_HTTP,"headerlen %d larger than %d. Failing.", - (int)headerlen, (int)max_headerlen-1); - return -1; - } - if (max_bodylen <= bodylen) { - log_warn(LD_HTTP,"bodylen %d larger than %d. Failing.", - (int)bodylen, (int)max_bodylen-1); - return -1; - } - -#define CONTENT_LENGTH "\r\nContent-Length: " - p = (char*) tor_memstr(headers, headerlen, CONTENT_LENGTH); - if (p) { - int i; - i = atoi(p+strlen(CONTENT_LENGTH)); - if (i < 0) { - log_warn(LD_PROTOCOL, "Content-Length is less than zero; it looks like " - "someone is trying to crash us."); - return -1; - } - contentlen = i; - /* if content-length is malformed, then our body length is 0. fine. */ - log_debug(LD_HTTP,"Got a contentlen of %d.",(int)contentlen); - if (bodylen < contentlen) { - if (!force_complete) { - log_debug(LD_HTTP,"body not all here yet."); - return 0; /* not all there yet */ - } - } - if (bodylen > contentlen) { - bodylen = contentlen; - log_debug(LD_HTTP,"bodylen reduced to %d.",(int)bodylen); - } - } - /* all happy. copy into the appropriate places, and return 1 */ - if (headers_out) { - *headers_out = tor_malloc(headerlen+1); - fetch_from_buf(*headers_out, headerlen, buf); - (*headers_out)[headerlen] = 0; /* NUL terminate it */ - } - if (body_out) { - tor_assert(body_used); - *body_used = bodylen; - *body_out = tor_malloc(bodylen+1); - fetch_from_buf(*body_out, bodylen, buf); - (*body_out)[bodylen] = 0; /* NUL terminate it */ - } - check(); - return 1; -} - -/** - * Wait this many seconds before warning the user about using SOCKS unsafely - * again (requires that WarnUnsafeSocks is turned on). */ -#define SOCKS_WARN_INTERVAL 5 - -/** Warn that the user application has made an unsafe socks request using - * protocol <b>socks_protocol</b> on port <b>port</b>. Don't warn more than - * once per SOCKS_WARN_INTERVAL, unless <b>safe_socks</b> is set. */ -static void -log_unsafe_socks_warning(int socks_protocol, const char *address, - uint16_t port, int safe_socks) -{ - static ratelim_t socks_ratelim = RATELIM_INIT(SOCKS_WARN_INTERVAL); - - const or_options_t *options = get_options(); - if (! options->WarnUnsafeSocks) - return; - if (safe_socks) { - log_fn_ratelim(&socks_ratelim, LOG_WARN, LD_APP, - "Your application (using socks%d to port %d) is giving " - "Tor only an IP address. Applications that do DNS resolves " - "themselves may leak information. Consider using Socks4A " - "(e.g. via privoxy or socat) instead. For more information, " - "please see https://wiki.torproject.org/TheOnionRouter/" - "TorFAQ#SOCKSAndDNS.%s", - socks_protocol, - (int)port, - safe_socks ? " Rejecting." : ""); - } - control_event_client_status(LOG_WARN, - "DANGEROUS_SOCKS PROTOCOL=SOCKS%d ADDRESS=%s:%d", - socks_protocol, address, (int)port); -} - -/** Do not attempt to parse socks messages longer than this. This value is - * actually significantly higher than the longest possible socks message. */ -#define MAX_SOCKS_MESSAGE_LEN 512 - -/** Return a new socks_request_t. */ -socks_request_t * -socks_request_new(void) -{ - return tor_malloc_zero(sizeof(socks_request_t)); -} - -/** Free all storage held in the socks_request_t <b>req</b>. */ -void -socks_request_free(socks_request_t *req) -{ - if (!req) - return; - if (req->username) { - memwipe(req->username, 0x10, req->usernamelen); - tor_free(req->username); - } - if (req->password) { - memwipe(req->password, 0x04, req->passwordlen); - tor_free(req->password); - } - memwipe(req, 0xCC, sizeof(socks_request_t)); - tor_free(req); -} - -/** There is a (possibly incomplete) socks handshake on <b>buf</b>, of one - * of the forms - * - socks4: "socksheader username\\0" - * - socks4a: "socksheader username\\0 destaddr\\0" - * - socks5 phase one: "version #methods methods" - * - socks5 phase two: "version command 0 addresstype..." - * If it's a complete and valid handshake, and destaddr fits in - * MAX_SOCKS_ADDR_LEN bytes, then pull the handshake off the buf, - * assign to <b>req</b>, and return 1. - * - * If it's invalid or too big, return -1. - * - * Else it's not all there yet, leave buf alone and return 0. - * - * If you want to specify the socks reply, write it into <b>req->reply</b> - * and set <b>req->replylen</b>, else leave <b>req->replylen</b> alone. - * - * If <b>log_sockstype</b> is non-zero, then do a notice-level log of whether - * the connection is possibly leaking DNS requests locally or not. - * - * If <b>safe_socks</b> is true, then reject unsafe socks protocols. - * - * If returning 0 or -1, <b>req->address</b> and <b>req->port</b> are - * undefined. - */ -int -fetch_from_buf_socks(buf_t *buf, socks_request_t *req, - int log_sockstype, int safe_socks) -{ - int res; - ssize_t n_drain; - size_t want_length = 128; - - if (buf->datalen < 2) /* version and another byte */ - return 0; - - do { - n_drain = 0; - buf_pullup(buf, want_length); - tor_assert(buf->head && buf->head->datalen >= 2); - want_length = 0; - - res = parse_socks(buf->head->data, buf->head->datalen, req, log_sockstype, - safe_socks, &n_drain, &want_length); - - if (n_drain < 0) - buf_clear(buf); - else if (n_drain > 0) - buf_remove_from_front(buf, n_drain); - - } while (res == 0 && buf->head && want_length < buf->datalen && - buf->datalen >= 2); - - return res; -} - -/** The size of the header of an Extended ORPort message: 2 bytes for - * COMMAND, 2 bytes for BODYLEN */ -#define EXT_OR_CMD_HEADER_SIZE 4 - -/** Read <b>buf</b>, which should contain an Extended ORPort message - * from a transport proxy. If well-formed, create and populate - * <b>out</b> with the Extended ORport message. Return 0 if the - * buffer was incomplete, 1 if it was well-formed and -1 if we - * encountered an error while parsing it. */ -int -fetch_ext_or_command_from_buf(buf_t *buf, ext_or_cmd_t **out) -{ - char hdr[EXT_OR_CMD_HEADER_SIZE]; - uint16_t len; - - check(); - if (buf->datalen < EXT_OR_CMD_HEADER_SIZE) - return 0; - peek_from_buf(hdr, sizeof(hdr), buf); - len = ntohs(get_uint16(hdr+2)); - if (buf->datalen < (unsigned)len + EXT_OR_CMD_HEADER_SIZE) - return 0; - *out = ext_or_cmd_new(len); - (*out)->cmd = ntohs(get_uint16(hdr)); - (*out)->len = len; - buf_remove_from_front(buf, EXT_OR_CMD_HEADER_SIZE); - fetch_from_buf((*out)->body, len, buf); - return 1; -} - -/** Create a SOCKS5 reply message with <b>reason</b> in its REP field and - * have Tor send it as error response to <b>req</b>. - */ -static void -socks_request_set_socks5_error(socks_request_t *req, - socks5_reply_status_t reason) -{ - req->replylen = 10; - memset(req->reply,0,10); - - req->reply[0] = 0x05; // VER field. - req->reply[1] = reason; // REP field. - req->reply[3] = 0x01; // ATYP field. -} - -/** Implementation helper to implement fetch_from_*_socks. Instead of looking - * at a buffer's contents, we look at the <b>datalen</b> bytes of data in - * <b>data</b>. Instead of removing data from the buffer, we set - * <b>drain_out</b> to the amount of data that should be removed (or -1 if the - * buffer should be cleared). Instead of pulling more data into the first - * chunk of the buffer, we set *<b>want_length_out</b> to the number of bytes - * we'd like to see in the input buffer, if they're available. */ -static int -parse_socks(const char *data, size_t datalen, socks_request_t *req, - int log_sockstype, int safe_socks, ssize_t *drain_out, - size_t *want_length_out) -{ - unsigned int len; - char tmpbuf[TOR_ADDR_BUF_LEN+1]; - tor_addr_t destaddr; - uint32_t destip; - uint8_t socksver; - char *next, *startaddr; - unsigned char usernamelen, passlen; - struct in_addr in; - - if (datalen < 2) { - /* We always need at least 2 bytes. */ - *want_length_out = 2; - return 0; - } - - if (req->socks_version == 5 && !req->got_auth) { - /* See if we have received authentication. Strictly speaking, we should - also check whether we actually negotiated username/password - authentication. But some broken clients will send us authentication - even if we negotiated SOCKS_NO_AUTH. */ - if (*data == 1) { /* username/pass version 1 */ - /* Format is: authversion [1 byte] == 1 - usernamelen [1 byte] - username [usernamelen bytes] - passlen [1 byte] - password [passlen bytes] */ - usernamelen = (unsigned char)*(data + 1); - if (datalen < 2u + usernamelen + 1u) { - *want_length_out = 2u + usernamelen + 1u; - return 0; - } - passlen = (unsigned char)*(data + 2u + usernamelen); - if (datalen < 2u + usernamelen + 1u + passlen) { - *want_length_out = 2u + usernamelen + 1u + passlen; - return 0; - } - req->replylen = 2; /* 2 bytes of response */ - req->reply[0] = 1; /* authversion == 1 */ - req->reply[1] = 0; /* authentication successful */ - log_debug(LD_APP, - "socks5: Accepted username/password without checking."); - if (usernamelen) { - req->username = tor_memdup(data+2u, usernamelen); - req->usernamelen = usernamelen; - } - if (passlen) { - req->password = tor_memdup(data+3u+usernamelen, passlen); - req->passwordlen = passlen; - } - *drain_out = 2u + usernamelen + 1u + passlen; - req->got_auth = 1; - *want_length_out = 7; /* Minimal socks5 command. */ - return 0; - } else if (req->auth_type == SOCKS_USER_PASS) { - /* unknown version byte */ - log_warn(LD_APP, "Socks5 username/password version %d not recognized; " - "rejecting.", (int)*data); - return -1; - } - } - - socksver = *data; - - switch (socksver) { /* which version of socks? */ - case 5: /* socks5 */ - - if (req->socks_version != 5) { /* we need to negotiate a method */ - unsigned char nummethods = (unsigned char)*(data+1); - int have_user_pass, have_no_auth; - int r=0; - tor_assert(!req->socks_version); - if (datalen < 2u+nummethods) { - *want_length_out = 2u+nummethods; - return 0; - } - if (!nummethods) - return -1; - req->replylen = 2; /* 2 bytes of response */ - req->reply[0] = 5; /* socks5 reply */ - have_user_pass = (memchr(data+2, SOCKS_USER_PASS, nummethods) !=NULL); - have_no_auth = (memchr(data+2, SOCKS_NO_AUTH, nummethods) !=NULL); - if (have_user_pass && !(have_no_auth && req->socks_prefer_no_auth)) { - req->auth_type = SOCKS_USER_PASS; - req->reply[1] = SOCKS_USER_PASS; /* tell client to use "user/pass" - auth method */ - req->socks_version = 5; /* remember we've already negotiated auth */ - log_debug(LD_APP,"socks5: accepted method 2 (username/password)"); - r=0; - } else if (have_no_auth) { - req->reply[1] = SOCKS_NO_AUTH; /* tell client to use "none" auth - method */ - req->socks_version = 5; /* remember we've already negotiated auth */ - log_debug(LD_APP,"socks5: accepted method 0 (no authentication)"); - r=0; - } else { - log_warn(LD_APP, - "socks5: offered methods don't include 'no auth' or " - "username/password. Rejecting."); - req->reply[1] = '\xFF'; /* reject all methods */ - r=-1; - } - /* Remove packet from buf. Some SOCKS clients will have sent extra - * junk at this point; let's hope it's an authentication message. */ - *drain_out = 2u + nummethods; - - return r; - } - if (req->auth_type != SOCKS_NO_AUTH && !req->got_auth) { - log_warn(LD_APP, - "socks5: negotiated authentication, but none provided"); - return -1; - } - /* we know the method; read in the request */ - log_debug(LD_APP,"socks5: checking request"); - if (datalen < 7) {/* basic info plus >=1 for addr plus 2 for port */ - *want_length_out = 7; - return 0; /* not yet */ - } - req->command = (unsigned char) *(data+1); - if (req->command != SOCKS_COMMAND_CONNECT && - req->command != SOCKS_COMMAND_RESOLVE && - req->command != SOCKS_COMMAND_RESOLVE_PTR) { - /* not a connect or resolve or a resolve_ptr? we don't support it. */ - socks_request_set_socks5_error(req,SOCKS5_COMMAND_NOT_SUPPORTED); - - log_warn(LD_APP,"socks5: command %d not recognized. Rejecting.", - req->command); - return -1; - } - switch (*(data+3)) { /* address type */ - case 1: /* IPv4 address */ - case 4: /* IPv6 address */ { - const int is_v6 = *(data+3) == 4; - const unsigned addrlen = is_v6 ? 16 : 4; - log_debug(LD_APP,"socks5: ipv4 address type"); - if (datalen < 6+addrlen) {/* ip/port there? */ - *want_length_out = 6+addrlen; - return 0; /* not yet */ - } - - if (is_v6) - tor_addr_from_ipv6_bytes(&destaddr, data+4); - else - tor_addr_from_ipv4n(&destaddr, get_uint32(data+4)); - - tor_addr_to_str(tmpbuf, &destaddr, sizeof(tmpbuf), 1); - - if (strlen(tmpbuf)+1 > MAX_SOCKS_ADDR_LEN) { - socks_request_set_socks5_error(req, SOCKS5_GENERAL_ERROR); - log_warn(LD_APP, - "socks5 IP takes %d bytes, which doesn't fit in %d. " - "Rejecting.", - (int)strlen(tmpbuf)+1,(int)MAX_SOCKS_ADDR_LEN); - return -1; - } - strlcpy(req->address,tmpbuf,sizeof(req->address)); - req->port = ntohs(get_uint16(data+4+addrlen)); - *drain_out = 6+addrlen; - if (req->command != SOCKS_COMMAND_RESOLVE_PTR && - !addressmap_have_mapping(req->address,0)) { - log_unsafe_socks_warning(5, req->address, req->port, safe_socks); - if (safe_socks) { - socks_request_set_socks5_error(req, SOCKS5_NOT_ALLOWED); - return -1; - } - } - return 1; - } - case 3: /* fqdn */ - log_debug(LD_APP,"socks5: fqdn address type"); - if (req->command == SOCKS_COMMAND_RESOLVE_PTR) { - socks_request_set_socks5_error(req, - SOCKS5_ADDRESS_TYPE_NOT_SUPPORTED); - log_warn(LD_APP, "socks5 received RESOLVE_PTR command with " - "hostname type. Rejecting."); - return -1; - } - len = (unsigned char)*(data+4); - if (datalen < 7+len) { /* addr/port there? */ - *want_length_out = 7+len; - return 0; /* not yet */ - } - if (len+1 > MAX_SOCKS_ADDR_LEN) { - socks_request_set_socks5_error(req, SOCKS5_GENERAL_ERROR); - log_warn(LD_APP, - "socks5 hostname is %d bytes, which doesn't fit in " - "%d. Rejecting.", len+1,MAX_SOCKS_ADDR_LEN); - return -1; - } - memcpy(req->address,data+5,len); - req->address[len] = 0; - req->port = ntohs(get_uint16(data+5+len)); - *drain_out = 5+len+2; - - if (string_is_valid_ipv4_address(req->address) || - string_is_valid_ipv6_address(req->address)) { - log_unsafe_socks_warning(5,req->address,req->port,safe_socks); - - if (safe_socks) { - socks_request_set_socks5_error(req, SOCKS5_NOT_ALLOWED); - return -1; - } - } else if (!string_is_valid_hostname(req->address)) { - socks_request_set_socks5_error(req, SOCKS5_GENERAL_ERROR); - - log_warn(LD_PROTOCOL, - "Your application (using socks5 to port %d) gave Tor " - "a malformed hostname: %s. Rejecting the connection.", - req->port, escaped_safe_str_client(req->address)); - return -1; - } - if (log_sockstype) - log_notice(LD_APP, - "Your application (using socks5 to port %d) instructed " - "Tor to take care of the DNS resolution itself if " - "necessary. This is good.", req->port); - return 1; - default: /* unsupported */ - socks_request_set_socks5_error(req, - SOCKS5_ADDRESS_TYPE_NOT_SUPPORTED); - log_warn(LD_APP,"socks5: unsupported address type %d. Rejecting.", - (int) *(data+3)); - return -1; - } - tor_assert(0); - break; - case 4: { /* socks4 */ - enum {socks4, socks4a} socks4_prot = socks4a; - const char *authstart, *authend; - /* http://ss5.sourceforge.net/socks4.protocol.txt */ - /* http://ss5.sourceforge.net/socks4A.protocol.txt */ - - req->socks_version = 4; - if (datalen < SOCKS4_NETWORK_LEN) {/* basic info available? */ - *want_length_out = SOCKS4_NETWORK_LEN; - return 0; /* not yet */ - } - // buf_pullup(buf, 1280); - req->command = (unsigned char) *(data+1); - if (req->command != SOCKS_COMMAND_CONNECT && - req->command != SOCKS_COMMAND_RESOLVE) { - /* not a connect or resolve? we don't support it. (No resolve_ptr with - * socks4.) */ - log_warn(LD_APP,"socks4: command %d not recognized. Rejecting.", - req->command); - return -1; - } - - req->port = ntohs(get_uint16(data+2)); - destip = ntohl(get_uint32(data+4)); - if ((!req->port && req->command!=SOCKS_COMMAND_RESOLVE) || !destip) { - log_warn(LD_APP,"socks4: Port or DestIP is zero. Rejecting."); - return -1; - } - if (destip >> 8) { - log_debug(LD_APP,"socks4: destip not in form 0.0.0.x."); - in.s_addr = htonl(destip); - tor_inet_ntoa(&in,tmpbuf,sizeof(tmpbuf)); - if (strlen(tmpbuf)+1 > MAX_SOCKS_ADDR_LEN) { - log_debug(LD_APP,"socks4 addr (%d bytes) too long. Rejecting.", - (int)strlen(tmpbuf)); - return -1; - } - log_debug(LD_APP, - "socks4: successfully read destip (%s)", - safe_str_client(tmpbuf)); - socks4_prot = socks4; - } - - authstart = data + SOCKS4_NETWORK_LEN; - next = memchr(authstart, 0, - datalen-SOCKS4_NETWORK_LEN); - if (!next) { - if (datalen >= 1024) { - log_debug(LD_APP, "Socks4 user name too long; rejecting."); - return -1; - } - log_debug(LD_APP,"socks4: Username not here yet."); - *want_length_out = datalen+1024; /* More than we need, but safe */ - return 0; - } - authend = next; - tor_assert(next < data+datalen); - - startaddr = NULL; - if (socks4_prot != socks4a && - !addressmap_have_mapping(tmpbuf,0)) { - log_unsafe_socks_warning(4, tmpbuf, req->port, safe_socks); - - if (safe_socks) - return -1; - } - if (socks4_prot == socks4a) { - if (next+1 == data+datalen) { - log_debug(LD_APP,"socks4: No part of destaddr here yet."); - *want_length_out = datalen + 1024; /* More than we need, but safe */ - return 0; - } - startaddr = next+1; - next = memchr(startaddr, 0, data + datalen - startaddr); - if (!next) { - if (datalen >= 1024) { - log_debug(LD_APP,"socks4: Destaddr too long."); - return -1; - } - log_debug(LD_APP,"socks4: Destaddr not all here yet."); - *want_length_out = datalen + 1024; /* More than we need, but safe */ - return 0; - } - if (MAX_SOCKS_ADDR_LEN <= next-startaddr) { - log_warn(LD_APP,"socks4: Destaddr too long. Rejecting."); - return -1; - } - // tor_assert(next < buf->cur+buf->datalen); - - if (log_sockstype) - log_notice(LD_APP, - "Your application (using socks4a to port %d) instructed " - "Tor to take care of the DNS resolution itself if " - "necessary. This is good.", req->port); - } - log_debug(LD_APP,"socks4: Everything is here. Success."); - strlcpy(req->address, startaddr ? startaddr : tmpbuf, - sizeof(req->address)); - if (!tor_strisprint(req->address) || strchr(req->address,'\"')) { - log_warn(LD_PROTOCOL, - "Your application (using socks4 to port %d) gave Tor " - "a malformed hostname: %s. Rejecting the connection.", - req->port, escaped_safe_str_client(req->address)); - return -1; - } - if (authend != authstart) { - req->got_auth = 1; - req->usernamelen = authend - authstart; - req->username = tor_memdup(authstart, authend - authstart); - } - /* next points to the final \0 on inbuf */ - *drain_out = next - data + 1; - return 1; - } - case 'G': /* get */ - case 'H': /* head */ - case 'P': /* put/post */ - case 'C': /* connect */ - strlcpy((char*)req->reply, -"HTTP/1.0 501 Tor is not an HTTP Proxy\r\n" -"Content-Type: text/html; charset=iso-8859-1\r\n\r\n" -"<html>\n" -"<head>\n" -"<title>Tor is not an HTTP Proxy</title>\n" -"</head>\n" -"<body>\n" -"<h1>Tor is not an HTTP Proxy</h1>\n" -"<p>\n" -"It appears you have configured your web browser to use Tor as an HTTP proxy." -"\n" -"This is not correct: Tor is a SOCKS proxy, not an HTTP proxy.\n" -"Please configure your client accordingly.\n" -"</p>\n" -"<p>\n" -"See <a href=\"https://www.torproject.org/documentation.html\">" - "https://www.torproject.org/documentation.html</a> for more " - "information.\n" -"<!-- Plus this comment, to make the body response more than 512 bytes, so " -" IE will be willing to display it. Comment comment comment comment " -" comment comment comment comment comment comment comment comment.-->\n" -"</p>\n" -"</body>\n" -"</html>\n" - , MAX_SOCKS_REPLY_LEN); - req->replylen = strlen((char*)req->reply)+1; - /* fall through */ - default: /* version is not socks4 or socks5 */ - log_warn(LD_APP, - "Socks version %d not recognized. (Tor is not an http proxy.)", - *(data)); - { - /* Tell the controller the first 8 bytes. */ - char *tmp = tor_strndup(data, datalen < 8 ? datalen : 8); - control_event_client_status(LOG_WARN, - "SOCKS_UNKNOWN_PROTOCOL DATA=\"%s\"", - escaped(tmp)); - tor_free(tmp); - } - return -1; - } -} - -/** Inspect a reply from SOCKS server stored in <b>buf</b> according - * to <b>state</b>, removing the protocol data upon success. Return 0 on - * incomplete response, 1 on success and -1 on error, in which case - * <b>reason</b> is set to a descriptive message (free() when finished - * with it). - * - * As a special case, 2 is returned when user/pass is required - * during SOCKS5 handshake and user/pass is configured. - */ -int -fetch_from_buf_socks_client(buf_t *buf, int state, char **reason) -{ - ssize_t drain = 0; - int r; - if (buf->datalen < 2) - return 0; - - buf_pullup(buf, MAX_SOCKS_MESSAGE_LEN); - tor_assert(buf->head && buf->head->datalen >= 2); - - r = parse_socks_client((uint8_t*)buf->head->data, buf->head->datalen, - state, reason, &drain); - if (drain > 0) - buf_remove_from_front(buf, drain); - else if (drain < 0) - buf_clear(buf); - - return r; -} - -/** Implementation logic for fetch_from_*_socks_client. */ -static int -parse_socks_client(const uint8_t *data, size_t datalen, - int state, char **reason, - ssize_t *drain_out) -{ - unsigned int addrlen; - *drain_out = 0; - if (datalen < 2) - return 0; - - switch (state) { - case PROXY_SOCKS4_WANT_CONNECT_OK: - /* Wait for the complete response */ - if (datalen < 8) - return 0; - - if (data[1] != 0x5a) { - *reason = tor_strdup(socks4_response_code_to_string(data[1])); - return -1; - } - - /* Success */ - *drain_out = 8; - return 1; - - case PROXY_SOCKS5_WANT_AUTH_METHOD_NONE: - /* we don't have any credentials */ - if (data[1] != 0x00) { - *reason = tor_strdup("server doesn't support any of our " - "available authentication methods"); - return -1; - } - - log_info(LD_NET, "SOCKS 5 client: continuing without authentication"); - *drain_out = -1; - return 1; - - case PROXY_SOCKS5_WANT_AUTH_METHOD_RFC1929: - /* we have a username and password. return 1 if we can proceed without - * providing authentication, or 2 otherwise. */ - switch (data[1]) { - case 0x00: - log_info(LD_NET, "SOCKS 5 client: we have auth details but server " - "doesn't require authentication."); - *drain_out = -1; - return 1; - case 0x02: - log_info(LD_NET, "SOCKS 5 client: need authentication."); - *drain_out = -1; - return 2; - /* fall through */ - } - - *reason = tor_strdup("server doesn't support any of our available " - "authentication methods"); - return -1; - - case PROXY_SOCKS5_WANT_AUTH_RFC1929_OK: - /* handle server reply to rfc1929 authentication */ - if (data[1] != 0x00) { - *reason = tor_strdup("authentication failed"); - return -1; - } - - log_info(LD_NET, "SOCKS 5 client: authentication successful."); - *drain_out = -1; - return 1; - - case PROXY_SOCKS5_WANT_CONNECT_OK: - /* response is variable length. BND.ADDR, etc, isn't needed - * (don't bother with buf_pullup()), but make sure to eat all - * the data used */ - - /* wait for address type field to arrive */ - if (datalen < 4) - return 0; - - switch (data[3]) { - case 0x01: /* ip4 */ - addrlen = 4; - break; - case 0x04: /* ip6 */ - addrlen = 16; - break; - case 0x03: /* fqdn (can this happen here?) */ - if (datalen < 5) - return 0; - addrlen = 1 + data[4]; - break; - default: - *reason = tor_strdup("invalid response to connect request"); - return -1; - } - - /* wait for address and port */ - if (datalen < 6 + addrlen) - return 0; - - if (data[1] != 0x00) { - *reason = tor_strdup(socks5_response_code_to_string(data[1])); - return -1; - } - - *drain_out = 6 + addrlen; - return 1; - } - - /* shouldn't get here... */ - tor_assert(0); - - return -1; -} - -/** Return 1 iff buf looks more like it has an (obsolete) v0 controller - * command on it than any valid v1 controller command. */ -int -peek_buf_has_control0_command(buf_t *buf) -{ - if (buf->datalen >= 4) { - char header[4]; - uint16_t cmd; - peek_from_buf(header, sizeof(header), buf); - cmd = ntohs(get_uint16(header+2)); - if (cmd <= 0x14) - return 1; /* This is definitely not a v1 control command. */ - } - return 0; -} - -/** Return the index within <b>buf</b> at which <b>ch</b> first appears, - * or -1 if <b>ch</b> does not appear on buf. */ -static off_t -buf_find_offset_of_char(buf_t *buf, char ch) -{ - chunk_t *chunk; - off_t offset = 0; - for (chunk = buf->head; chunk; chunk = chunk->next) { - char *cp = memchr(chunk->data, ch, chunk->datalen); - if (cp) - return offset + (cp - chunk->data); - else - offset += chunk->datalen; - } - return -1; -} - -/** Try to read a single LF-terminated line from <b>buf</b>, and write it - * (including the LF), NUL-terminated, into the *<b>data_len</b> byte buffer - * at <b>data_out</b>. Set *<b>data_len</b> to the number of bytes in the - * line, not counting the terminating NUL. Return 1 if we read a whole line, - * return 0 if we don't have a whole line yet, and return -1 if the line - * length exceeds *<b>data_len</b>. - */ -int -fetch_from_buf_line(buf_t *buf, char *data_out, size_t *data_len) -{ - size_t sz; - off_t offset; - - if (!buf->head) - return 0; - - offset = buf_find_offset_of_char(buf, '\n'); - if (offset < 0) - return 0; - sz = (size_t) offset; - if (sz+2 > *data_len) { - *data_len = sz + 2; - return -1; - } - fetch_from_buf(data_out, sz+1, buf); - data_out[sz+1] = '\0'; - *data_len = sz+1; - return 1; -} - -/** Compress on uncompress the <b>data_len</b> bytes in <b>data</b> using the - * zlib state <b>state</b>, appending the result to <b>buf</b>. If - * <b>done</b> is true, flush the data in the state and finish the - * compression/uncompression. Return -1 on failure, 0 on success. */ -int -write_to_buf_zlib(buf_t *buf, tor_zlib_state_t *state, - const char *data, size_t data_len, - int done) -{ - char *next; - size_t old_avail, avail; - int over = 0; - - do { - int need_new_chunk = 0; - if (!buf->tail || ! CHUNK_REMAINING_CAPACITY(buf->tail)) { - size_t cap = data_len / 4; - buf_add_chunk_with_capacity(buf, cap, 1); - } - next = CHUNK_WRITE_PTR(buf->tail); - avail = old_avail = CHUNK_REMAINING_CAPACITY(buf->tail); - switch (tor_zlib_process(state, &next, &avail, &data, &data_len, done)) { - case TOR_ZLIB_DONE: - over = 1; - break; - case TOR_ZLIB_ERR: - return -1; - case TOR_ZLIB_OK: - if (data_len == 0) - over = 1; - break; - case TOR_ZLIB_BUF_FULL: - if (avail) { - /* Zlib says we need more room (ZLIB_BUF_FULL). Start a new chunk - * automatically, whether were going to or not. */ - need_new_chunk = 1; - } - break; - } - buf->datalen += old_avail - avail; - buf->tail->datalen += old_avail - avail; - if (need_new_chunk) { - buf_add_chunk_with_capacity(buf, data_len/4, 1); - } - - } while (!over); - check(); - return 0; -} - -/** Set *<b>output</b> to contain a copy of the data in *<b>input</b> */ -int -buf_set_to_copy(buf_t **output, - const buf_t *input) -{ - if (*output) - buf_free(*output); - *output = buf_copy(input); - return 0; -} - -/** Log an error and exit if <b>buf</b> is corrupted. - */ -void -assert_buf_ok(buf_t *buf) -{ - tor_assert(buf); - tor_assert(buf->magic == BUFFER_MAGIC); - - if (! buf->head) { - tor_assert(!buf->tail); - tor_assert(buf->datalen == 0); - } else { - chunk_t *ch; - size_t total = 0; - tor_assert(buf->tail); - for (ch = buf->head; ch; ch = ch->next) { - total += ch->datalen; - tor_assert(ch->datalen <= ch->memlen); - tor_assert(ch->data >= &ch->mem[0]); - tor_assert(ch->data <= &ch->mem[0]+ch->memlen); - if (ch->data == &ch->mem[0]+ch->memlen) { - static int warned = 0; - if (! warned) { - log_warn(LD_BUG, "Invariant violation in buf.c related to #15083"); - warned = 1; - } - } - tor_assert(ch->data+ch->datalen <= &ch->mem[0] + ch->memlen); - if (!ch->next) - tor_assert(ch == buf->tail); - } - tor_assert(buf->datalen == total); - } -} - |