diff options
Diffstat (limited to 'src/common/util.c')
| -rw-r--r-- | src/common/util.c | 249 |
1 files changed, 184 insertions, 65 deletions
diff --git a/src/common/util.c b/src/common/util.c index 5eb0f9a69b..3c2f6643ad 100644 --- a/src/common/util.c +++ b/src/common/util.c @@ -24,6 +24,8 @@ #include "torint.h" #include "container.h" #include "address.h" +#include "sandbox.h" +#include "backtrace.h" #ifdef _WIN32 #include <io.h> @@ -94,6 +96,23 @@ #endif /* ===== + * Assertion helper. + * ===== */ +/** Helper for tor_assert: report the assertion failure. */ +void +tor_assertion_failed_(const char *fname, unsigned int line, + const char *func, const char *expr) +{ + char buf[256]; + log_err(LD_BUG, "%s:%u: %s: Assertion %s failed; aborting.", + fname, line, func, expr); + tor_snprintf(buf, sizeof(buf), + "Assertion %s failed in %s at %s:%u", + expr, func, fname, line); + log_backtrace(LOG_ERR, LD_BUG, buf); +} + +/* ===== * Memory management * ===== */ #ifdef USE_DMALLOC @@ -879,6 +898,39 @@ tor_digest_is_zero(const char *digest) return tor_memeq(digest, ZERO_DIGEST, DIGEST_LEN); } +/** Return true if <b>string</b> is a valid '<key>=[<value>]' string. + * <value> is optional, to indicate the empty string. Log at logging + * <b>severity</b> if something ugly happens. */ +int +string_is_key_value(int severity, const char *string) +{ + /* position of equal sign in string */ + const char *equal_sign_pos = NULL; + + tor_assert(string); + + if (strlen(string) < 2) { /* "x=" is shortest args string */ + tor_log(severity, LD_GENERAL, "'%s' is too short to be a k=v value.", + escaped(string)); + return 0; + } + + equal_sign_pos = strchr(string, '='); + if (!equal_sign_pos) { + tor_log(severity, LD_GENERAL, "'%s' is not a k=v value.", escaped(string)); + return 0; + } + + /* validate that the '=' is not in the beginning of the string. */ + if (equal_sign_pos == string) { + tor_log(severity, LD_GENERAL, "'%s' is not a valid k=v value.", + escaped(string)); + return 0; + } + + return 1; +} + /** Return true iff the DIGEST256_LEN bytes in digest are all zero. */ int tor_digest256_is_zero(const char *digest) @@ -1190,6 +1242,43 @@ escaped(const char *s) return escaped_val_; } +/** Return a newly allocated string equal to <b>string</b>, except that every + * character in <b>chars_to_escape</b> is preceded by a backslash. */ +char * +tor_escape_str_for_pt_args(const char *string, const char *chars_to_escape) +{ + char *new_string = NULL; + char *new_cp = NULL; + size_t length, new_length; + + tor_assert(string); + + length = strlen(string); + + if (!length) /* If we were given the empty string, return the same. */ + return tor_strdup(""); + /* (new_length > SIZE_MAX) => ((length * 2) + 1 > SIZE_MAX) => + (length*2 > SIZE_MAX - 1) => (length > (SIZE_MAX - 1)/2) */ + if (length > (SIZE_MAX - 1)/2) /* check for overflow */ + return NULL; + + /* this should be enough even if all characters must be escaped */ + new_length = (length * 2) + 1; + + new_string = new_cp = tor_malloc(new_length); + + while (*string) { + if (strchr(chars_to_escape, *string)) + *new_cp++ = '\\'; + + *new_cp++ = *string++; + } + + *new_cp = '\0'; /* NUL-terminate the new string */ + + return new_string; +} + /* ===== * Time * ===== */ @@ -1741,7 +1830,7 @@ file_status(const char *fname) int r; f = tor_strdup(fname); clean_name_for_stat(f); - r = stat(f, &st); + r = stat(sandbox_intern_string(f), &st); tor_free(f); if (r) { if (errno == ENOENT) { @@ -1791,7 +1880,7 @@ check_private_dir(const char *dirname, cpd_check_t check, tor_assert(dirname); f = tor_strdup(dirname); clean_name_for_stat(f); - r = stat(f, &st); + r = stat(sandbox_intern_string(f), &st); tor_free(f); if (r) { if (errno != ENOENT) { @@ -1977,8 +2066,10 @@ start_writing_to_file(const char *fname, int open_flags, int mode, open_flags &= ~O_EXCL; new_file->rename_on_close = 1; } +#if O_BINARY != 0 if (open_flags & O_BINARY) new_file->binary = 1; +#endif new_file->fd = tor_open_cloexec(open_name, open_flags, mode); if (new_file->fd < 0) { @@ -2132,12 +2223,20 @@ write_chunks_to_file_impl(const char *fname, const smartlist_t *chunks, return -1; } -/** Given a smartlist of sized_chunk_t, write them atomically to a file - * <b>fname</b>, overwriting or creating the file as necessary. */ +/** Given a smartlist of sized_chunk_t, write them to a file + * <b>fname</b>, overwriting or creating the file as necessary. + * If <b>no_tempfile</b> is 0 then the file will be written + * atomically. */ int -write_chunks_to_file(const char *fname, const smartlist_t *chunks, int bin) +write_chunks_to_file(const char *fname, const smartlist_t *chunks, int bin, + int no_tempfile) { int flags = OPEN_FLAGS_REPLACE|(bin?O_BINARY:O_TEXT); + + if (no_tempfile) { + /* O_APPEND stops write_chunks_to_file from using tempfiles */ + flags |= O_APPEND; + } return write_chunks_to_file_impl(fname, chunks, flags); } @@ -2158,9 +2257,9 @@ write_bytes_to_file_impl(const char *fname, const char *str, size_t len, /** As write_str_to_file, but does not assume a NUL-terminated * string. Instead, we write <b>len</b> bytes, starting at <b>str</b>. */ -int -write_bytes_to_file(const char *fname, const char *str, size_t len, - int bin) +MOCK_IMPL(int, +write_bytes_to_file,(const char *fname, const char *str, size_t len, + int bin)) { return write_bytes_to_file_impl(fname, str, len, OPEN_FLAGS_REPLACE|(bin?O_BINARY:O_TEXT)); @@ -3022,9 +3121,10 @@ tor_listdir(const char *dirname) FindClose(handle); tor_free(pattern); #else + const char *prot_dname = sandbox_intern_string(dirname); DIR *d; struct dirent *de; - if (!(d = opendir(dirname))) + if (!(d = opendir(prot_dname))) return NULL; result = smartlist_new(); @@ -3320,14 +3420,59 @@ tor_join_win_cmdline(const char *argv[]) return joined_argv; } +/* As format_{hex,dex}_number_sigsafe, but takes a <b>radix</b> argument + * in range 2..16 inclusive. */ +static int +format_number_sigsafe(unsigned long x, char *buf, int buf_len, + unsigned int radix) +{ + unsigned long tmp; + int len; + char *cp; + + /* NOT tor_assert. This needs to be safe to run from within a signal handler, + * and from within the 'tor_assert() has failed' code. */ + if (radix < 2 || radix > 16) + return 0; + + /* Count how many digits we need. */ + tmp = x; + len = 1; + while (tmp >= radix) { + tmp /= radix; + ++len; + } + + /* Not long enough */ + if (!buf || len >= buf_len) + return 0; + + cp = buf + len; + *cp = '\0'; + do { + unsigned digit = (unsigned) (x % radix); + tor_assert(cp > buf); + --cp; + *cp = "0123456789ABCDEF"[digit]; + x /= radix; + } while (x); + + /* NOT tor_assert; see above. */ + if (cp != buf) { + abort(); + } + + return len; +} + /** - * Helper function to output hex numbers, called by - * format_helper_exit_status(). This writes the hexadecimal digits of x into - * buf, up to max_len digits, and returns the actual number of digits written. - * If there is insufficient space, it will write nothing and return 0. + * Helper function to output hex numbers from within a signal handler. + * + * Writes the nul-terminated hexadecimal digits of <b>x</b> into a buffer + * <b>buf</b> of size <b>buf_len</b>, and return the actual number of digits + * written, not counting the terminal NUL. * - * This function DOES NOT add a terminating NUL character to its output: be - * careful! + * If there is insufficient space, write nothing and return 0. * * This accepts an unsigned int because format_helper_exit_status() needs to * call it with a signed int and an unsigned char, and since the C standard @@ -3342,46 +3487,19 @@ tor_join_win_cmdline(const char *argv[]) * arbitrary C functions. */ int -format_hex_number_for_helper_exit_status(unsigned int x, char *buf, - int max_len) +format_hex_number_sigsafe(unsigned long x, char *buf, int buf_len) { - int len; - unsigned int tmp; - char *cur; - - /* Sanity check */ - if (!buf || max_len <= 0) - return 0; - - /* How many chars do we need for x? */ - if (x > 0) { - len = 0; - tmp = x; - while (tmp > 0) { - tmp >>= 4; - ++len; - } - } else { - len = 1; - } - - /* Bail if we would go past the end of the buffer */ - if (len > max_len) - return 0; - - /* Point to last one */ - cur = buf + len - 1; - - /* Convert x to hex */ - do { - *cur-- = "0123456789ABCDEF"[x & 0xf]; - x >>= 4; - } while (x != 0 && cur >= buf); + return format_number_sigsafe(x, buf, buf_len, 16); +} - /* Return len */ - return len; +/** As format_hex_number_sigsafe, but format the number in base 10. */ +int +format_dec_number_sigsafe(unsigned long x, char *buf, int buf_len) +{ + return format_number_sigsafe(x, buf, buf_len, 10); } +#ifndef _WIN32 /** Format <b>child_state</b> and <b>saved_errno</b> as a hex string placed in * <b>hex_errno</b>. Called between fork and _exit, so must be signal-handler * safe. @@ -3397,7 +3515,7 @@ format_hex_number_for_helper_exit_status(unsigned int x, char *buf, * On success return the number of characters added to hex_errno, not counting * the terminating NUL; return -1 on error. */ -int +STATIC int format_helper_exit_status(unsigned char child_state, int saved_errno, char *hex_errno) { @@ -3428,8 +3546,8 @@ format_helper_exit_status(unsigned char child_state, int saved_errno, cur = hex_errno; /* Emit child_state */ - written = format_hex_number_for_helper_exit_status(child_state, - cur, left); + written = format_hex_number_sigsafe(child_state, cur, left); + if (written <= 0) goto err; @@ -3458,8 +3576,7 @@ format_helper_exit_status(unsigned char child_state, int saved_errno, } /* Emit unsigned_errno */ - written = format_hex_number_for_helper_exit_status(unsigned_errno, - cur, left); + written = format_hex_number_sigsafe(unsigned_errno, cur, left); if (written <= 0) goto err; @@ -3490,6 +3607,7 @@ format_helper_exit_status(unsigned char child_state, int saved_errno, done: return res; } +#endif /* Maximum number of file descriptors, if we cannot get it via sysconf() */ #define DEFAULT_MAX_FD 256 @@ -3685,7 +3803,7 @@ tor_spawn_background(const char *const filename, const char **argv, TRUE, // handles are inherited /*(TODO: set CREATE_NEW CONSOLE/PROCESS_GROUP to make GetExitCodeProcess() * work?) */ - 0, // creation flags + CREATE_NO_WINDOW, // creation flags (env==NULL) ? NULL : env->windows_environment_block, NULL, // use parent's current directory &siStartInfo, // STARTUPINFO pointer @@ -3906,9 +4024,9 @@ tor_spawn_background(const char *const filename, const char **argv, * <b>process_handle</b>. * If <b>also_terminate_process</b> is true, also terminate the * process of the process handle. */ -void -tor_process_handle_destroy(process_handle_t *process_handle, - int also_terminate_process) +MOCK_IMPL(void, +tor_process_handle_destroy,(process_handle_t *process_handle, + int also_terminate_process)) { if (!process_handle) return; @@ -4417,9 +4535,9 @@ stream_status_to_string(enum stream_status stream_status) /** Return a smartlist containing lines outputted from * <b>handle</b>. Return NULL on error, and set * <b>stream_status_out</b> appropriately. */ -smartlist_t * -tor_get_lines_from_handle(HANDLE *handle, - enum stream_status *stream_status_out) +MOCK_IMPL(smartlist_t *, +tor_get_lines_from_handle, (HANDLE *handle, + enum stream_status *stream_status_out)) { int pos; char stdout_buf[600] = {0}; @@ -4507,8 +4625,9 @@ log_from_handle(HANDLE *pipe, int severity) /** Return a smartlist containing lines outputted from * <b>handle</b>. Return NULL on error, and set * <b>stream_status_out</b> appropriately. */ -smartlist_t * -tor_get_lines_from_handle(FILE *handle, enum stream_status *stream_status_out) +MOCK_IMPL(smartlist_t *, +tor_get_lines_from_handle, (FILE *handle, + enum stream_status *stream_status_out)) { enum stream_status stream_status; char stdout_buf[400]; |