From: Lennart Poettering Date: Fri, 22 Dec 2017 14:07:22 +0000 (+0100) Subject: process-util: move fork_agent() to process-util.[ch] X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=c99d561e23c06c521951ead4ef7c06747fea7dce;p=elogind.git process-util: move fork_agent() to process-util.[ch] It's a relatively small wrapper around safe_fork() now, hence let's move it over, and make its signature even more alike. Also, set a different process name for the polkit and askpw agents. --- diff --git a/src/basic/process-util.c b/src/basic/process-util.c index 900e42ee8..e1b2664f3 100644 --- a/src/basic/process-util.c +++ b/src/basic/process-util.c @@ -1285,6 +1285,77 @@ int safe_fork_full( return 0; } +int fork_agent(const char *name, const int except[], unsigned n_except, pid_t *ret_pid, const char *path, ...) { + bool stdout_is_tty, stderr_is_tty; + unsigned n, i; + va_list ap; + char **l; + int r; + + assert(path); + + /* Spawns a temporary TTY agent, making sure it goes away when we go away */ + + r = safe_fork_full(name, except, n_except, FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_CLOSE_ALL_FDS, ret_pid); + if (r < 0) + return r; + if (r > 0) + return 0; + + /* In the child: */ + + stdout_is_tty = isatty(STDOUT_FILENO); + stderr_is_tty = isatty(STDERR_FILENO); + + if (!stdout_is_tty || !stderr_is_tty) { + int fd; + + /* Detach from stdout/stderr. and reopen + * /dev/tty for them. This is important to + * ensure that when systemctl is started via + * popen() or a similar call that expects to + * read EOF we actually do generate EOF and + * not delay this indefinitely by because we + * keep an unused copy of stdin around. */ + fd = open("/dev/tty", O_WRONLY); + if (fd < 0) { + log_error_errno(errno, "Failed to open /dev/tty: %m"); + _exit(EXIT_FAILURE); + } + + if (!stdout_is_tty && dup2(fd, STDOUT_FILENO) < 0) { + log_error_errno(errno, "Failed to dup2 /dev/tty: %m"); + _exit(EXIT_FAILURE); + } + + if (!stderr_is_tty && dup2(fd, STDERR_FILENO) < 0) { + log_error_errno(errno, "Failed to dup2 /dev/tty: %m"); + _exit(EXIT_FAILURE); + } + + if (fd > STDERR_FILENO) + close(fd); + } + + /* Count arguments */ + va_start(ap, path); + for (n = 0; va_arg(ap, char*); n++) + ; + va_end(ap); + + /* Allocate strv */ + l = alloca(sizeof(char *) * (n + 1)); + + /* Fill in arguments */ + va_start(ap, path); + for (i = 0; i <= n; i++) + l[i] = va_arg(ap, char*); + va_end(ap); + + execv(path, l); + _exit(EXIT_FAILURE); +} + #if 0 /// UNNEEDED by elogind static const char *const ioprio_class_table[] = { [IOPRIO_CLASS_NONE] = "none", diff --git a/src/basic/process-util.h b/src/basic/process-util.h index ffd4096e5..9128d0b2c 100644 --- a/src/basic/process-util.h +++ b/src/basic/process-util.h @@ -170,3 +170,5 @@ int safe_fork_full(const char *name, const int except_fds[], size_t n_except_fds static inline int safe_fork(const char *name, ForkFlags flags, pid_t *ret_pid) { return safe_fork_full(name, NULL, 0, flags, ret_pid); } + +int fork_agent(const char *name, const int except[], unsigned n_except, pid_t *pid, const char *path, ...); diff --git a/src/basic/util.c b/src/basic/util.c index 51b2a9d14..342c4bd09 100644 --- a/src/basic/util.c +++ b/src/basic/util.c @@ -188,80 +188,6 @@ int prot_from_flags(int flags) { } #endif // 0 -int fork_agent(pid_t *pid, const int except[], unsigned n_except, const char *path, ...) { - bool stdout_is_tty, stderr_is_tty; - pid_t agent_pid; - unsigned n, i; - va_list ap; - char **l; - int r; - - assert(pid); - assert(path); - - /* Spawns a temporary TTY agent, making sure it goes away when - * we go away */ - - r = safe_fork_full("(sd-agent)", except, n_except, FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_CLOSE_ALL_FDS, &agent_pid); - if (r < 0) - return r; - if (r > 0) - return 0; - - /* In the child: */ - - stdout_is_tty = isatty(STDOUT_FILENO); - stderr_is_tty = isatty(STDERR_FILENO); - - if (!stdout_is_tty || !stderr_is_tty) { - int fd; - - /* Detach from stdout/stderr. and reopen - * /dev/tty for them. This is important to - * ensure that when systemctl is started via - * popen() or a similar call that expects to - * read EOF we actually do generate EOF and - * not delay this indefinitely by because we - * keep an unused copy of stdin around. */ - fd = open("/dev/tty", O_WRONLY); - if (fd < 0) { - log_error_errno(errno, "Failed to open /dev/tty: %m"); - _exit(EXIT_FAILURE); - } - - if (!stdout_is_tty && dup2(fd, STDOUT_FILENO) < 0) { - log_error_errno(errno, "Failed to dup2 /dev/tty: %m"); - _exit(EXIT_FAILURE); - } - - if (!stderr_is_tty && dup2(fd, STDERR_FILENO) < 0) { - log_error_errno(errno, "Failed to dup2 /dev/tty: %m"); - _exit(EXIT_FAILURE); - } - - if (fd > STDERR_FILENO) - close(fd); - } - - /* Count arguments */ - va_start(ap, path); - for (n = 0; va_arg(ap, char*); n++) - ; - va_end(ap); - - /* Allocate strv */ - l = alloca(sizeof(char *) * (n + 1)); - - /* Fill in arguments */ - va_start(ap, path); - for (i = 0; i <= n; i++) - l[i] = va_arg(ap, char*); - va_end(ap); - - execv(path, l); - _exit(EXIT_FAILURE); -} - bool in_initrd(void) { struct statfs s; diff --git a/src/basic/util.h b/src/basic/util.h index f4314c674..30448a3b8 100644 --- a/src/basic/util.h +++ b/src/basic/util.h @@ -92,8 +92,6 @@ bool kexec_loaded(void); int prot_from_flags(int flags) _const_; #endif // 0 -int fork_agent(pid_t *pid, const int except[], unsigned n_except, const char *path, ...); - bool in_initrd(void); void in_initrd_force(bool value); diff --git a/src/shared/spawn-polkit-agent.c b/src/shared/spawn-polkit-agent.c index 423069fb0..c6bd65eb7 100644 --- a/src/shared/spawn-polkit-agent.c +++ b/src/shared/spawn-polkit-agent.c @@ -38,9 +38,8 @@ static pid_t agent_pid = 0; int polkit_agent_open(void) { - int r; - int pipe_fd[2]; char notify_fd[DECIMAL_STR_MAX(int) + 1]; + int pipe_fd[2], r; if (agent_pid > 0) return 0; @@ -49,8 +48,7 @@ int polkit_agent_open(void) { if (geteuid() == 0) return 0; - /* We check STDIN here, not STDOUT, since this is about input, - * not output */ + /* We check STDIN here, not STDOUT, since this is about input, not output */ if (!isatty(STDIN_FILENO)) return 0; @@ -59,8 +57,9 @@ int polkit_agent_open(void) { xsprintf(notify_fd, "%i", pipe_fd[1]); - r = fork_agent(&agent_pid, + r = fork_agent("(polkit-agent)", &pipe_fd[1], 1, + &agent_pid, POLKIT_AGENT_BINARY_PATH, POLKIT_AGENT_BINARY_PATH, "--notify-fd", notify_fd, "--fallback", NULL);