From e8b42e513fa97af5c9978eb95ea97712f0ea5bbb Mon Sep 17 00:00:00 2001 From: Tavian Barnes Date: Fri, 28 Jun 2019 20:34:33 -0400 Subject: Merge everything into one file --- spawn.c | 226 ---------------------------------------------------------------- 1 file changed, 226 deletions(-) delete mode 100644 spawn.c (limited to 'spawn.c') diff --git a/spawn.c b/spawn.c deleted file mode 100644 index 18ddd72..0000000 --- a/spawn.c +++ /dev/null @@ -1,226 +0,0 @@ -/**************************************************************************** - * bfs * - * Copyright (C) 2018-2019 Tavian Barnes * - * * - * Permission to use, copy, modify, and/or distribute this software for any * - * purpose with or without fee is hereby granted. * - * * - * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * - * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * - * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * - * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * - * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * - * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * - * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * - ****************************************************************************/ - -#include "spawn.h" -#include "util.h" -#include -#include -#include -#include -#include -#include -#include - -/** - * Types of spawn actions. - */ -enum bfs_spawn_op { - BFS_SPAWN_CLOSE, - BFS_SPAWN_DUP2, - BFS_SPAWN_FCHDIR, -}; - -/** - * A spawn action. - */ -struct bfs_spawn_action { - struct bfs_spawn_action *next; - - enum bfs_spawn_op op; - int in_fd; - int out_fd; -}; - -int bfs_spawn_init(struct bfs_spawn *ctx) { - ctx->flags = 0; - ctx->actions = NULL; - ctx->tail = &ctx->actions; - return 0; -} - -int bfs_spawn_destroy(struct bfs_spawn *ctx) { - struct bfs_spawn_action *action = ctx->actions; - while (action) { - struct bfs_spawn_action *next = action->next; - free(action); - action = next; - } - return 0; -} - -int bfs_spawn_setflags(struct bfs_spawn *ctx, enum bfs_spawn_flags flags) { - ctx->flags = flags; - return 0; -} - -/** Add a spawn action to the chain. */ -static struct bfs_spawn_action *bfs_spawn_add(struct bfs_spawn *ctx, enum bfs_spawn_op op) { - struct bfs_spawn_action *action = malloc(sizeof(*action)); - if (action) { - action->next = NULL; - action->op = op; - action->in_fd = -1; - action->out_fd = -1; - - *ctx->tail = action; - ctx->tail = &action->next; - } - return action; -} - -int bfs_spawn_addclose(struct bfs_spawn *ctx, int fd) { - if (fd < 0) { - errno = EBADF; - return -1; - } - - struct bfs_spawn_action *action = bfs_spawn_add(ctx, BFS_SPAWN_CLOSE); - if (action) { - action->out_fd = fd; - return 0; - } else { - return -1; - } -} - -int bfs_spawn_adddup2(struct bfs_spawn *ctx, int oldfd, int newfd) { - if (oldfd < 0 || newfd < 0) { - errno = EBADF; - return -1; - } - - struct bfs_spawn_action *action = bfs_spawn_add(ctx, BFS_SPAWN_DUP2); - if (action) { - action->in_fd = oldfd; - action->out_fd = newfd; - return 0; - } else { - return -1; - } -} - -int bfs_spawn_addfchdir(struct bfs_spawn *ctx, int fd) { - if (fd < 0) { - errno = EBADF; - return -1; - } - - struct bfs_spawn_action *action = bfs_spawn_add(ctx, BFS_SPAWN_FCHDIR); - if (action) { - action->in_fd = fd; - return 0; - } else { - return -1; - } -} - -/** Facade for execvpe() which is non-standard. */ -static int bfs_execvpe(const char *exe, char **argv, char **envp) { -#if __GLIBC__ || __linux__ || __NetBSD__ || __OpenBSD__ - return execvpe(exe, argv, envp); -#else - extern char **environ; - environ = envp; - return execvp(exe, argv); -#endif -} - -/** Actually exec() the new process. */ -static void bfs_spawn_exec(const char *exe, const struct bfs_spawn *ctx, char **argv, char **envp, int pipefd[2]) { - int error; - enum bfs_spawn_flags flags = ctx ? ctx->flags : 0; - const struct bfs_spawn_action *actions = ctx ? ctx->actions : NULL; - - close(pipefd[0]); - - for (const struct bfs_spawn_action *action = actions; action; action = action->next) { - // Move the error-reporting pipe out of the way if necessary - if (action->in_fd == pipefd[1] || action->out_fd == pipefd[1]) { - int fd = dup(pipefd[1]); - if (fd < 0) { - goto fail; - } - close(pipefd[1]); - pipefd[1] = fd; - } - - switch (action->op) { - case BFS_SPAWN_CLOSE: - if (close(action->out_fd) != 0) { - goto fail; - } - break; - case BFS_SPAWN_DUP2: - if (dup2(action->in_fd, action->out_fd) < 0) { - goto fail; - } - break; - case BFS_SPAWN_FCHDIR: - if (fchdir(action->in_fd) != 0) { - goto fail; - } - break; - } - } - - if (flags & BFS_SPAWN_USEPATH) { - bfs_execvpe(exe, argv, envp); - } else { - execve(exe, argv, envp); - } - -fail: - error = errno; - while (write(pipefd[1], &error, sizeof(error)) < sizeof(error)); - close(pipefd[1]); - _Exit(127); -} - -pid_t bfs_spawn(const char *exe, const struct bfs_spawn *ctx, char **argv, char **envp) { - // Use a pipe to report errors from the child - int pipefd[2]; - if (pipe_cloexec(pipefd) != 0) { - return -1; - } - - int error; - pid_t pid = fork(); - - if (pid < 0) { - error = errno; - close(pipefd[1]); - close(pipefd[0]); - errno = error; - return -1; - } else if (pid == 0) { - // Child - bfs_spawn_exec(exe, ctx, argv, envp, pipefd); - } - - // Parent - close(pipefd[1]); - - ssize_t nbytes = read(pipefd[0], &error, sizeof(error)); - close(pipefd[0]); - if (nbytes == sizeof(error)) { - int wstatus; - waitpid(pid, &wstatus, 0); - errno = error; - return -1; - } - - return pid; -} -- cgit v1.2.3