|
Tor 0.4.9.0-alpha-dev
|
Handling code for unrecoverable emergencies, at a lower level than the logging code. More...
#include "orconfig.h"#include <stdarg.h>#include <stdlib.h>#include <string.h>#include <stdio.h>#include "lib/err/torerr.h"#include "lib/err/backtrace.h"Go to the source code of this file.
Functions | |
| static int | tor_log_err_sigsafe_write (const char *s) |
| void | tor_log_err_sigsafe (const char *m,...) |
| int | tor_log_get_sigsafe_err_fds (const int **out) |
| void | tor_log_set_sigsafe_err_fds (const int *fds, int n) |
| void | tor_log_reset_sigsafe_err_fds (void) |
| void | tor_log_flush_sigsafe_err_fds (void) |
| void | tor_log_sigsafe_err_set_granularity (int ms) |
| void | tor_raw_assertion_failed_msg_ (const char *file, int line, const char *expr, const char *msg) |
| void | tor_raw_abort_ (void) |
| static int | format_number_sigsafe (unsigned long x, char *buf, int buf_len, unsigned int radix) |
| int | format_hex_number_sigsafe (unsigned long x, char *buf, int buf_len) |
| int | format_dec_number_sigsafe (unsigned long x, char *buf, int buf_len) |
Variables | |
| static int | sigsafe_log_fds [TOR_SIGSAFE_LOG_MAX_FDS] = { STDERR_FILENO } |
| static int | n_sigsafe_log_fds = 1 |
| static int | log_granularity = 1000 |
Handling code for unrecoverable emergencies, at a lower level than the logging code.
There are plenty of places that things can go wrong in Tor's backend libraries: the allocator can fail, the locking subsystem can fail, and so on. But since these subsystems are used themselves by the logging module, they can't use the logging code directly to report their errors.
As a workaround, the logging code provides this module with a set of raw fds to be used for reporting errors in the lowest-level Tor code.
Definition in file torerr.c.
| int format_dec_number_sigsafe | ( | unsigned long | x, |
| char * | buf, | ||
| int | buf_len | ||
| ) |
As format_hex_number_sigsafe, but format the number in base 10.
Definition at line 305 of file torerr.c.
Referenced by tor_log_err_sigsafe(), and tor_raw_assertion_failed_msg_().
| int format_hex_number_sigsafe | ( | unsigned long | x, |
| char * | buf, | ||
| int | buf_len | ||
| ) |
Helper function to output hex numbers from within a signal handler.
Writes the nul-terminated hexadecimal digits of x into a buffer buf of size buf_len, and return the actual number of digits written, not counting the terminal NUL.
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 does not guarantee that an int is wider than a char (an int must be at least 16 bits but it is permitted for a char to be that wide as well), we can't assume a signed int is sufficient to accommodate an unsigned char. Thus, callers will still need to add any required '-' to the final string.
For most purposes, you'd want to use tor_snprintf("%x") instead of this function; it's designed to be used in code paths where you can't call arbitrary C functions.
|
static |
| void tor_log_err_sigsafe | ( | const char * | m, |
| ... | |||
| ) |
Given a list of string arguments ending with a NULL, writes them to our logs and to stderr (if possible). This function is safe to call from within a signal handler.
Definition at line 70 of file torerr.c.
Referenced by nodump_mem(), noinherit_mem(), string_is_utf8(), and tor_raw_assertion_failed_msg_().
|
static |
Write s to each element of sigsafe_log_fds. Return 0 on success, -1 on failure.
Definition at line 53 of file torerr.c.
Referenced by tor_log_err_sigsafe(), and tor_raw_assertion_failed_msg_().
| void tor_log_flush_sigsafe_err_fds | ( | void | ) |
Flush the list of fds that get errors from inside a signal handler or other emergency condition. These fds are shared with the logging code: flushing them also flushes the log buffers.
This function is safe to call during signal handlers.
Definition at line 161 of file torerr.c.
Referenced by tor_raw_abort_().
| int tor_log_get_sigsafe_err_fds | ( | const int ** | out | ) |
Set *out to a pointer to an array of the fds to log errors to from inside a signal handler or other emergency condition. Return the number of elements in the array.
Definition at line 103 of file torerr.c.
Referenced by tor_log_flush_sigsafe_err_fds().
| void tor_log_reset_sigsafe_err_fds | ( | void | ) |
| void tor_log_set_sigsafe_err_fds | ( | const int * | fds, |
| int | n | ||
| ) |
Update the list of fds that get errors from inside a signal handler or other emergency condition. Ignore any beyond the first TOR_SIGSAFE_LOG_MAX_FDS.
These fds must remain open even after the log module has shut down. (And they should remain open even while logs are being reconfigured.) Therefore, any fds closed by the log module should be dup()ed, and the duplicate fd should be given to the err module in fds. In particular, the log module closes the file log fds, but does not close the stdio log fds.
If fds is NULL or n is 0, clears the list of error fds.
Definition at line 123 of file torerr.c.
Referenced by tor_log_reset_sigsafe_err_fds().
| void tor_log_sigsafe_err_set_granularity | ( | int | ms | ) |
Set the granularity (in ms) to use when reporting fatal errors outside the logging system.
Definition at line 182 of file torerr.c.
Referenced by set_log_time_granularity().
| void tor_raw_abort_ | ( | void | ) |
Call the abort() function to kill the current process with a fatal error. But first, flush the raw error file descriptors, so error messages are written before process termination.
Definition at line 222 of file torerr.c.
Referenced by tor_abort_().
| void tor_raw_assertion_failed_msg_ | ( | const char * | file, |
| int | line, | ||
| const char * | expr, | ||
| const char * | msg | ||
| ) |
|
static |
Log granularity in milliseconds.
Definition at line 48 of file torerr.c.
Referenced by tor_log_err_sigsafe(), and tor_log_sigsafe_err_set_granularity().
|
static |
The number of elements used in sigsafe_log_fds
Definition at line 46 of file torerr.c.
Referenced by tor_log_err_sigsafe_write(), tor_log_get_sigsafe_err_fds(), and tor_log_set_sigsafe_err_fds().
|
static |
Array of fds to log crash-style warnings to.
Definition at line 44 of file torerr.c.
Referenced by tor_log_err_sigsafe_write(), tor_log_get_sigsafe_err_fds(), and tor_log_set_sigsafe_err_fds().
1.9.4