diff options
Diffstat (limited to 'src/common')
| -rw-r--r-- | src/common/util.c | 70 | ||||
| -rw-r--r-- | src/common/util.h | 2 |
2 files changed, 42 insertions, 30 deletions
diff --git a/src/common/util.c b/src/common/util.c index 8b9979cc4..c18458355 100644 --- a/src/common/util.c +++ b/src/common/util.c @@ -3034,20 +3034,24 @@ format_helper_exit_status(unsigned char child_state, int saved_errno, #define SPAWN_ERROR_MESSAGE "ERR: Failed to spawn background process - code " -/** Start a program in the background. If <b>filename</b> contains a '/', - * then it will be treated as an absolute or relative path. Otherwise the - * system path will be searched for <b>filename</b>. The strings in - * <b>argv</b> will be passed as the command line arguments of the child - * program (following convention, argv[0] should normally be the filename of - * the executable). The last element of argv must be NULL. If the child - * program is launched, the PID will be returned and <b>stdout_read</b> and - * <b>stdout_err</b> will be set to file descriptors from which the stdout - * and stderr, respectively, output of the child program can be read, and the - * stdin of the child process shall be set to /dev/null. Otherwise returns - * -1. Some parts of this code are based on the POSIX subprocess module from +/** Start a program in the background. If <b>filename</b> contains a '/', then + * it will be treated as an absolute or relative path. Otherwise, on + * non-Windows systems, the system path will be searched for <b>filename</b>. + * On Windows, only the current directory will be searched. Here, to search the + * system path (as well as the application directory, current working + * directory, and system directories), set filename to NULL. + * + * The strings in <b>argv</b> will be passed as the command line arguments of + * the child program (following convention, argv[0] should normally be the + * filename of the executable, and this must be the case if <b>filename</b> is + * NULL). The last element of argv must be NULL. If the child program is + * launched, a handle to it will be returned. + * + * Some parts of this code are based on the POSIX subprocess module from * Python, and example code from * http://msdn.microsoft.com/en-us/library/ms682499%28v=vs.85%29.aspx. */ + process_handle_t tor_spawn_background(const char *const filename, const char **argv) { @@ -3122,8 +3126,8 @@ tor_spawn_background(const char *const filename, const char **argv) /* Create the child process */ - retval = CreateProcess(filename, // module name - joined_argv, // command line + retval = CreateProcess(filename, // module name + joined_argv, // command line NULL, // process security attributes NULL, // primary thread security attributes TRUE, // handles are inherited @@ -3270,7 +3274,7 @@ tor_spawn_background(const char *const filename, const char **argv) /* Write the error message. GCC requires that we check the return value, but there is nothing we can do if it fails */ - // TODO: Don't use STDOUT, use a pipe set up just for this purpose + /* TODO: Don't use STDOUT, use a pipe set up just for this purpose */ nbytes = write(STDOUT_FILENO, error_message, error_message_length); nbytes = write(STDOUT_FILENO, hex_errno, sizeof(hex_errno)); @@ -3291,7 +3295,9 @@ tor_spawn_background(const char *const filename, const char **argv) return process_handle; } - // TODO: If the child process forked but failed to exec, waitpid it + process_handle.pid = pid; + + /* TODO: If the child process forked but failed to exec, waitpid it */ /* Return read end of the pipes to caller, and close write end */ process_handle.stdout_pipe = stdout_pipe[0]; @@ -3301,8 +3307,6 @@ tor_spawn_background(const char *const filename, const char **argv) log_warn(LD_GENERAL, "Failed to close write end of stdout pipe in parent process: %s", strerror(errno)); - /* Do not return -1, because the child is running, so the parent - needs to know about the pid in order to reap it later */ } process_handle.stderr_pipe = stderr_pipe[0]; @@ -3312,12 +3316,9 @@ tor_spawn_background(const char *const filename, const char **argv) log_warn(LD_GENERAL, "Failed to close write end of stderr pipe in parent process: %s", strerror(errno)); - /* Do not return -1, because the child is running, so the parent - needs to know about the pid in order to reap it later */ } process_handle.status = 1; - process_handle.pid = pid; /* Set stdout/stderr pipes to be non-blocking */ fcntl(process_handle.stdout_pipe, F_SETFL, O_NONBLOCK); fcntl(process_handle.stderr_pipe, F_SETFL, O_NONBLOCK); @@ -3403,7 +3404,12 @@ tor_get_exit_code(const process_handle_t process_handle, } #ifdef MS_WINDOWS -/* Windows equivalent of read_all */ +/** Read from a handle <b>h</b> into <b>buf</b>, up to <b>count</b> bytes. If + * <b>hProcess</b> is NULL, the function will return immediately if there is + * nothing more to read. Otherwise <b>hProcess</b> should be set to the handle + * to the process owning the <b>h</b>. In this case, the function will exit + * only once the process has exited, or <b>count</b> bytes are read. Returns + * the number of bytes read, or -1 on error. */ ssize_t tor_read_all_handle(HANDLE h, char *buf, size_t count, HANDLE hProcess) { @@ -3416,6 +3422,7 @@ tor_read_all_handle(HANDLE h, char *buf, size_t count, HANDLE hProcess) return -1; while (numread != count) { + /* Check if there is anything to read */ retval = PeekNamedPipe(h, NULL, 0, NULL, &byte_count, NULL); if (!retval) { log_warn(LD_GENERAL, @@ -3459,6 +3466,7 @@ tor_read_all_handle(HANDLE h, char *buf, size_t count, HANDLE hProcess) } #endif +/* Read from stdout of a process until the process exits. */ ssize_t tor_read_all_from_process_stdout(const process_handle_t process_handle, char *buf, size_t count) @@ -3471,6 +3479,7 @@ tor_read_all_from_process_stdout(const process_handle_t process_handle, #endif } +/* Read from stdout of a process until the process exits. */ ssize_t tor_read_all_from_process_stderr(const process_handle_t process_handle, char *buf, size_t count) @@ -3496,38 +3505,41 @@ log_from_handle(HANDLE *pipe, int severity) pos = tor_read_all_handle(pipe, buf, sizeof(buf) - 1, NULL); if (pos < 0) { - // Error + /* Error */ log_warn(LD_GENERAL, "Failed to read data from subprocess"); return -1; } if (0 == pos) { - // There's nothing to read (process is busy or has exited) + /* There's nothing to read (process is busy or has exited) */ log_debug(LD_GENERAL, "Subprocess had nothing to say"); return 0; } - // End with a null even if there isn't a \r\n at the end - // TODO: What if this is a partial line? + /* End with a null even if there isn't a \r\n at the end */ + /* TODO: What if this is a partial line? */ buf[pos] = '\0'; log_debug(LD_GENERAL, "Subprocess had %d bytes to say", pos); + /* Split buf into lines and log each one */ next = 0; // Start of the next line while (next < pos) { start = next; // Look for the end of this line for (cur=start; cur<pos; cur++) { + /* On Windows \r means end of line */ if ('\r' == buf[cur]) { buf[cur] = '\0'; next = cur + 1; - if ((cur + 1) < pos && buf[cur+1] < pos) { + /* If \n follows, remove it too */ + if ((cur + 1) < pos && '\n' == buf[cur+1]) { buf[cur + 1] = '\0'; next = cur + 2; } - // Line starts at start and ends with a null (was \r\n) + /* Line starts at start and ends with a null (was \r\n) */ break; } - // Line starts at start and ends at the end of a string - // but we already added a null in earlier + /* Line starts at start and ends at the end of a string + but we already added a null in earlier */ } log_fn(severity, LD_GENERAL, "Port forwarding helper says: %s", buf+start); } diff --git a/src/common/util.h b/src/common/util.h index b4ae3f858..2602628ab 100644 --- a/src/common/util.h +++ b/src/common/util.h @@ -366,7 +366,7 @@ typedef struct process_handle_s { int stderr_pipe; FILE *stdout_handle; FILE *stderr_handle; - int pid; + pid_t pid; #endif // MS_WINDOWS } process_handle_t; |