diff --git a/src/or/buffers.c b/src/or/buffers.c index 280c1794e5..6a37614138 100644 --- a/src/or/buffers.c +++ b/src/or/buffers.c @@ -2,16 +2,18 @@ /* See LICENSE for licensing information */ /* $Id$ */ -/* buffers.c */ +/***** + * buffers.c: Abstractions for buffered IO. + *****/ #include "or.h" #define BUFFER_MAGIC 0xB0FFF312u struct buf_t { - uint32_t magic; /* for debugging */ - char *mem; - size_t len; - size_t datalen; + uint32_t magic; /* Magic cookie for debugging: Must be set to BUFFER_MAGIC */ + char *mem; /* Storage for data in the buffer */ + size_t len; /* Maximum amount of data that 'mem' can hold. */ + size_t datalen; /* Number of bytes currently in 'mem'. */ }; /* Size, in bytes, for newly allocated buffers. Should be a power of 2. */ @@ -23,7 +25,7 @@ struct buf_t { * than this size. */ #define MIN_BUF_SHRINK_SIZE (16*1024) -/* Change a buffer's capacity. Must only be called when */ +/* Change a buffer's capacity. new_capacity must be <= buf->datalen. */ static INLINE void buf_resize(buf_t *buf, size_t new_capacity) { tor_assert(buf->datalen <= new_capacity); @@ -88,33 +90,42 @@ static INLINE void buf_remove_from_front(buf_t *buf, size_t n) { buf_shrink_if_underfull(buf); } -/* Find the first instance of str on buf. If none exists, return -1. - * Otherwise, return index of the first character in buf _after_ the - * first instance of str. +/* Find the first instance of the str_len byte string 'sr' on the + * buf_len byte string 'bufstr'. Strings are not necessary + * NUL-terminated. If none exists, return -1. Otherwise, return index + * of the first character in bufstr _after_ the first instance of str. */ -static int find_str_in_str(const char *str, int str_len, - const char *buf, int buf_len) +/* XXXX The way this function is used, we could always get away with + * XXXX assuming that str is NUL terminated, and use strstr instead. */ +static int find_mem_in_mem(const char *str, int str_len, + const char *bufstr, int buf_len) { const char *location; - const char *last_possible = buf + buf_len - str_len; + const char *last_possible = bufstr + buf_len - str_len; - tor_assert(str && str_len > 0 && buf); + tor_assert(str && str_len > 0 && bufstr); if(buf_len < str_len) return -1; - for(location = buf; location <= last_possible; location++) + for(location = bufstr; location <= last_possible; location++) if((*location == *str) && !memcmp(location+1, str+1, str_len-1)) - return location-buf+str_len; + return location-bufstr+str_len; return -1; } -int find_on_inbuf(char *string, int string_len, buf_t *buf) { - return find_str_in_str(string, string_len, buf->mem, buf->datalen); +#if 0 +/* Find the first occurence of the string_len byte string 'str' on the + * buffer 'buf'. If none exists, return -1. Otherwise, return index + * of the first character on the buffer _after_ the first instance of str. + */ +int find_on_inbuf(char *str, int string_len, buf_t *buf) { + return find_mem_in_mem(str, string_len, buf->mem, buf->datalen); } +#endif -/* Create and return a new buf of size 'size' +/* Create and return a new buf with capacity 'capacity'. */ buf_t *buf_new_with_capacity(size_t size) { buf_t *buf; @@ -129,31 +140,40 @@ buf_t *buf_new_with_capacity(size_t size) { return buf; } +/* Allocate and return a new buffer with default capacity. */ buf_t *buf_new() { return buf_new_with_capacity(INITIAL_BUF_SIZE); } +/* Remove all data from 'buf' */ void buf_clear(buf_t *buf) { buf->datalen = 0; } +/* Return the number of bytes stored in 'buf' */ size_t buf_datalen(const buf_t *buf) { return buf->datalen; } +/* Return the maximum bytes that can be stored in 'buf' before buf + * needs to resize. */ size_t buf_capacity(const buf_t *buf) { return buf->len; } +/* For testing only: Return a pointer to the raw memory stored in 'buf'. + */ const char *_buf_peek_raw_buffer(const buf_t *buf) { return buf->mem; } +/* Release storage held by 'buf'. + */ void buf_free(buf_t *buf) { assert_buf_ok(buf); buf->magic = 0xDEADBEEF; @@ -161,12 +181,11 @@ void buf_free(buf_t *buf) { tor_free(buf); } -/* read from socket s, writing onto end of buf. - * read at most 'at_most' bytes, and in any case don't read more than - * will fit based on buflen. - * If read() returns 0, set *reached_eof to 1 and return 0. If you want - * to tear down the connection return -1, else return the number of - * bytes read. +/* Read from socket s, writing onto end of buf. Read at most + * 'at_most' bytes, resizing the buffer as necessary. If read() + * returns 0, set *reached_eof to 1 and return 0. Return -1 on error; + * else return the number of bytes read. Return 0 if read() would + * block. */ int read_to_buf(int s, size_t at_most, buf_t *buf, int *reached_eof) { @@ -190,7 +209,7 @@ int read_to_buf(int s, size_t at_most, buf_t *buf, int *reached_eof) { if(!ERRNO_IS_EAGAIN(tor_socket_errno(s))) { /* it's a real error */ return -1; } - return 0; + return 0; /* would block. */ } else if (read_result == 0) { log_fn(LOG_DEBUG,"Encountered eof"); *reached_eof = 1; @@ -203,6 +222,8 @@ int read_to_buf(int s, size_t at_most, buf_t *buf, int *reached_eof) { } } +/* As read_to_buf, but reads from a TLS connection. + */ int read_to_buf_tls(tor_tls *tls, size_t at_most, buf_t *buf) { int r; tor_assert(tls); @@ -233,9 +254,13 @@ int read_to_buf_tls(tor_tls *tls, size_t at_most, buf_t *buf) { return r; } +/* Write data from 'buf' to the socket 's'. Write at most + * *buf_flushlen bytes, and decrement *buf_flushlen by the number of + * bytes actually written. Return the number of bytes written on + * success, -1 on failure. Returns 0 if write() would block. + */ int flush_buf(int s, buf_t *buf, int *buf_flushlen) { - /* push from buf onto s * then memmove to front of buf * return -1 or how many bytes you just flushed */ @@ -267,6 +292,8 @@ int flush_buf(int s, buf_t *buf, int *buf_flushlen) } } +/* As flush_buf, but writes data to a TLS connection. + */ int flush_buf_tls(tor_tls *tls, buf_t *buf, int *buf_flushlen) { int r; @@ -286,6 +313,9 @@ int flush_buf_tls(tor_tls *tls, buf_t *buf, int *buf_flushlen) return r; } +/* Append string_len bytes from 'string' to the end of 'buf'. + * Return the new length of the buffer on success, -1 on failure. + */ int write_to_buf(const char *string, int string_len, buf_t *buf) { /* append string to buf (growing as needed, return -1 if "too big") @@ -306,6 +336,11 @@ int write_to_buf(const char *string, int string_len, buf_t *buf) { return buf->datalen; } + +/* Remove string_len bytes from the front of 'buf', and store them + * into 'string'. Returns the new buffer size. string_len 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, @@ -346,7 +381,7 @@ int fetch_from_buf_http(buf_t *buf, assert_buf_ok(buf); headers = buf->mem; - i = find_on_inbuf("\r\n\r\n", 4, buf); + i = find_mem_in_mem("\r\n\r\n", 4, buf->mem, buf->datalen); if(i < 0) { log_fn(LOG_DEBUG,"headers not all here yet."); return 0; @@ -366,7 +401,7 @@ int fetch_from_buf_http(buf_t *buf, } #define CONTENT_LENGTH "\r\nContent-Length: " - i = find_str_in_str(CONTENT_LENGTH, strlen(CONTENT_LENGTH), + i = find_mem_in_mem(CONTENT_LENGTH, strlen(CONTENT_LENGTH), headers, headerlen); if(i > 0) { contentlen = atoi(headers+i); @@ -585,7 +620,8 @@ int fetch_from_buf_socks(buf_t *buf, socks_request_t *req) { } } - +/* Log an error and exit if 'buf' is corrupted. + */ void assert_buf_ok(buf_t *buf) { tor_assert(buf); diff --git a/src/or/connection.c b/src/or/connection.c index 074bd8c820..ebe1430c5c 100644 --- a/src/or/connection.c +++ b/src/or/connection.c @@ -655,9 +655,11 @@ int connection_fetch_from_buf(char *string, int len, connection_t *conn) { return fetch_from_buf(string, len, conn->inbuf); } +/* int connection_find_on_inbuf(char *string, int len, connection_t *conn) { return find_on_inbuf(string, len, conn->inbuf); } +*/ int connection_wants_to_flush(connection_t *conn) { return conn->outbuf_flushlen; diff --git a/src/or/or.h b/src/or/or.h index 83d1bb7267..76d99170df 100644 --- a/src/or/or.h +++ b/src/or/or.h @@ -646,7 +646,7 @@ struct socks_request_t { /********************************* buffers.c ***************************/ -int find_on_inbuf(char *string, int string_len, buf_t *buf); +/* int find_on_inbuf(char *string, int string_len, buf_t *buf); */ buf_t *buf_new(); buf_t *buf_new_with_capacity(size_t size); @@ -802,7 +802,7 @@ int connection_handle_read(connection_t *conn); int connection_read_to_buf(connection_t *conn); int connection_fetch_from_buf(char *string, int len, connection_t *conn); -int connection_find_on_inbuf(char *string, int len, connection_t *conn); +/* int connection_find_on_inbuf(char *string, int len, connection_t *conn); */ int connection_wants_to_flush(connection_t *conn); int connection_outbuf_too_full(connection_t *conn); diff --git a/src/or/test.c b/src/or/test.c index 6e37ba1435..9d1fffc74c 100644 --- a/src/or/test.c +++ b/src/or/test.c @@ -136,6 +136,8 @@ test_buffers() { close(s); + +#if 0 /**** * find_on_inbuf ****/ @@ -156,6 +158,7 @@ test_buffers() { test_eq(-1, find_on_inbuf("AX", 2, buf)); /* Make sure we use the string length */ test_eq(((int)'d')+1, find_on_inbuf("abcdX", 4, buf)); +#endif /**** * fetch_from_buf