--- /dev/null
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/wait.h>
+
+#include <process/process.h>
+#include <talloc/talloc.h>
+#include <waiter/waiter.h>
+#include <log/log.h>
+
+struct procset {
+ struct waitset *waitset;
+ struct list async_list;
+ int sigchld_pipe[2];
+ struct waiter *sigchld_waiter;
+};
+
+/* Internal data type for process handling
+ *
+ * Allocation: these structures may have multiple references:
+ * - from the original ctx pointer
+ * - due to inclusion in async_list
+ * - due to a currently-registered waiter
+ *
+ */
+struct process_info {
+#ifdef DEBUG
+ /* prevent talloc_free(process) from working */
+ int __pad;
+#endif
+ struct process process;
+ struct list_item async_list;
+ int stdout_buf_len;
+ struct waiter *stdout_waiter;
+ int stdout_pipe[2];
+ void *orig_ctx;
+};
+
+static struct procset *procset;
+
+static struct process_info *get_info(struct process *process)
+{
+ return container_of(process, struct process_info, process);
+}
+
+/* Read as much as possible into the currently-allocated stdout buffer, and
+ * possibly realloc it for the next read */
+static int process_read_stdout_once(struct process_info *procinfo)
+{
+ struct process *process = &procinfo->process;
+ int rc, fd, max_len;
+
+ assert(process->keep_stdout);
+
+ fd = procinfo->stdout_pipe[0];
+
+ max_len = procinfo->stdout_buf_len - process->stdout_len - 1;
+
+ rc = read(fd, process->stdout_buf + process->stdout_len, max_len);
+ if (rc <= 0)
+ return rc;
+
+ process->stdout_len += rc;
+ if (process->stdout_len == procinfo->stdout_buf_len - 1) {
+ procinfo->stdout_buf_len *= 2;
+ process->stdout_buf = talloc_realloc(procinfo,
+ process->stdout_buf, char,
+ procinfo->stdout_buf_len);
+ }
+
+ return rc;
+}
+
+static int process_setup_stdout_pipe(struct process_info *procinfo)
+{
+ int rc;
+
+ if (!procinfo->process.keep_stdout)
+ return 0;
+
+ procinfo->stdout_buf_len = 4096;
+ procinfo->process.stdout_len = 0;
+ procinfo->process.stdout_buf = talloc_array(procinfo, char,
+ procinfo->stdout_buf_len);
+
+ rc = pipe(procinfo->stdout_pipe);
+ if (rc) {
+ pb_log("pipe failed");
+ return rc;
+ }
+ return 0;
+}
+
+static void process_setup_stdout_parent(struct process_info *procinfo)
+{
+ if (!procinfo->process.keep_stdout)
+ return;
+
+ close(procinfo->stdout_pipe[1]);
+}
+
+static void process_setup_stdout_child(struct process_info *procinfo)
+{
+ int log = fileno(pb_log_get_stream());
+
+ if (procinfo->process.keep_stdout)
+ dup2(procinfo->stdout_pipe[1], STDOUT_FILENO);
+ else
+ dup2(log, STDOUT_FILENO);
+
+ dup2(log, STDERR_FILENO);
+}
+
+static void process_finish_stdout(struct process_info *procinfo)
+{
+ close(procinfo->stdout_pipe[0]);
+ procinfo->process.stdout_buf[procinfo->process.stdout_len] = '\0';
+}
+
+static int process_read_stdout(struct process_info *procinfo)
+{
+ int rc;
+
+ if (!procinfo->process.keep_stdout)
+ return 0;
+
+ do {
+ rc = process_read_stdout_once(procinfo);
+ } while (rc > 0);
+
+ process_finish_stdout(procinfo);
+
+ return rc < 0 ? rc : 0;
+}
+
+static int process_stdout_cb(void *arg)
+{
+ struct process_info *procinfo = arg;
+ int rc;
+
+ rc = process_read_stdout_once(procinfo);
+
+ /* if we're going to signal to the waitset that we're done (ie, non-zero
+ * return value), then the waiters will remove us, so we drop the
+ * reference */
+ if (rc < 0) {
+ talloc_unlink(procset, procinfo);
+ procinfo->stdout_waiter = NULL;
+ rc = -1;
+ } else {
+ rc = 0;
+ }
+
+ return rc;
+}
+
+static void sigchld_sigaction(int signo, siginfo_t *info,
+ void *arg __attribute__((unused)))
+{
+ pid_t pid;
+ int rc;
+
+ if (signo != SIGCHLD)
+ return;
+
+ pid = info->si_pid;
+
+ rc = write(procset->sigchld_pipe[1], &pid, sizeof(pid));
+ if (rc != sizeof(pid))
+ pb_log("%s: write failed: %s\n", __func__, strerror(errno));
+}
+
+static int sigchld_pipe_event(void *arg)
+{
+ struct process_info *procinfo;
+ struct procset *procset = arg;
+ struct process *process;
+ int pid, rc;
+
+ rc = read(procset->sigchld_pipe[0], &pid, sizeof(pid));
+ if (rc != sizeof(pid))
+ return 0;
+
+ process = NULL;
+ list_for_each_entry(&procset->async_list, procinfo, async_list) {
+ if (procinfo->process.pid == pid) {
+ process = &procinfo->process;
+ break;
+ }
+ }
+
+ /* We'll receive SIGCHLD for synchronous processes too; just ignore */
+ if (!process)
+ return 0;
+
+ rc = waitpid(process->pid, &process->exit_status, WNOHANG);
+
+ /* if the process is still running, ignore the event. We leave
+ * the process in async_list so we can manage the final signal */
+ if (rc == 0)
+ return 0;
+
+ /* ensure we have all of the child's stdout */
+ process_read_stdout(procinfo);
+
+ if (process->exit_cb)
+ process->exit_cb(process);
+
+ list_remove(&procinfo->async_list);
+ talloc_unlink(procset, procinfo);
+
+ return 0;
+}
+
+static int process_fini(void *p)
+{
+ struct procset *procset = p;
+ struct sigaction sa;
+
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_handler = SIG_DFL;
+
+ sigaction(SIGCHLD, &sa, NULL);
+
+ waiter_remove(procset->sigchld_waiter);
+
+ close(procset->sigchld_pipe[0]);
+ close(procset->sigchld_pipe[1]);
+ return 0;
+}
+
+struct procset *process_init(void *ctx, struct waitset *set)
+{
+ struct sigaction sa;
+ int rc;
+
+ procset = talloc(ctx, struct procset);
+ procset->waitset = set;
+ list_init(&procset->async_list);
+
+ rc = pipe(procset->sigchld_pipe);
+ if (rc) {
+ pb_log("%s: pipe() failed: %s\n", __func__, strerror(errno));
+ goto err_free;
+ }
+
+ procset->sigchld_waiter = waiter_register_io(set,
+ procset->sigchld_pipe[0], WAIT_IN,
+ sigchld_pipe_event, procset);
+ if (!procset->sigchld_waiter)
+ goto err_close;
+
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_sigaction = sigchld_sigaction;
+ sa.sa_flags = SA_SIGINFO | SA_NOCLDSTOP;
+
+ rc = sigaction(SIGCHLD, &sa, NULL);
+ if (rc) {
+ pb_log("%s: sigaction() failed: %s\n", __func__,
+ strerror(errno));
+ goto err_remove;
+ }
+
+ talloc_set_destructor(procset, process_fini);
+
+ return procset;
+
+err_remove:
+ waiter_remove(procset->sigchld_waiter);
+err_close:
+ close(procset->sigchld_pipe[0]);
+ close(procset->sigchld_pipe[1]);
+err_free:
+ talloc_free(procset);
+ return NULL;
+}
+
+struct process *process_create(void *ctx)
+{
+ struct process_info *info = talloc_zero(ctx, struct process_info);
+ info->orig_ctx = ctx;
+ return &info->process;
+}
+
+void process_release(struct process *process)
+{
+ struct process_info *info = get_info(process);
+ talloc_unlink(info->orig_ctx, info);
+}
+
+static int process_run_common(struct process_info *procinfo)
+{
+ struct process *process = &procinfo->process;
+ const char *arg;
+ char *logmsg;
+ pid_t pid;
+ int rc, i;
+
+ logmsg = talloc_asprintf(procinfo, " exe: %s\n argv:", process->path);
+ for (i = 0, arg = process->argv[i]; arg; i++, arg = process->argv[i])
+ logmsg = talloc_asprintf_append(logmsg, " '%s'", arg);
+
+ pb_log("Running command:\n%s\n", logmsg);
+
+ rc = process_setup_stdout_pipe(procinfo);
+ if (rc)
+ return rc;
+
+ pid = fork();
+ if (pid < 0) {
+ pb_log("%s: fork failed: %s\n", __func__, strerror(errno));
+ return pid;
+ }
+
+ if (pid == 0) {
+ process_setup_stdout_child(procinfo);
+ execvp(process->path, (char * const *)process->argv);
+ exit(EXIT_FAILURE);
+ }
+
+ process_setup_stdout_parent(procinfo);
+ process->pid = pid;
+
+ return 0;
+}
+
+int process_run_sync(struct process *process)
+{
+ struct process_info *procinfo = get_info(process);
+ int rc;
+
+ rc = process_run_common(procinfo);
+ if (rc)
+ return rc;
+
+ process_read_stdout(procinfo);
+
+ rc = waitpid(process->pid, &process->exit_status, 0);
+ if (rc == -1) {
+ pb_log("%s: waitpid failed: %s\n", __func__, strerror(errno));
+ return rc;
+ }
+
+ return 0;
+}
+
+int process_run_async(struct process *process)
+{
+ struct process_info *procinfo = get_info(process);
+ int rc;
+
+ rc = process_run_common(procinfo);
+ if (rc)
+ return rc;
+
+ if (process->keep_stdout) {
+ procinfo->stdout_waiter = waiter_register_io(procset->waitset,
+ procinfo->stdout_pipe[0],
+ WAIT_IN, process_stdout_cb,
+ procinfo);
+ talloc_reference(procset, procinfo);
+ }
+
+ list_add(&procset->async_list, &procinfo->async_list);
+ talloc_reference(procset, procinfo);
+
+ return 0;
+}
+
+void process_stop_async(struct process *process)
+{
+ kill(process->pid, SIGTERM);
+}
+
+int process_run_simple_argv(void *ctx, const char *argv[])
+{
+ struct process *process;
+ int rc;
+
+ process = process_create(ctx);
+
+ process->path = argv[0];
+ process->argv = argv;
+
+ rc = process_run_sync(process);
+
+ if (!rc)
+ rc = process->exit_status;
+
+ process_release(process);
+
+ return rc;
+}
+
+int process_run_simple(void *ctx, const char *name, ...)
+{
+ int rc, i, n_argv = 1;
+ const char **argv;
+ va_list ap;
+
+ va_start(ap, name);
+ while (va_arg(ap, char *))
+ n_argv++;
+ va_end(ap);
+
+ argv = talloc_array(ctx, const char *, n_argv + 1);
+ argv[0] = name;
+
+ va_start(ap, name);
+ for (i = 1; i < n_argv; i++)
+ argv[i] = va_arg(ap, const char *);
+ va_end(ap);
+
+ argv[i] = NULL;
+
+ rc = process_run_simple_argv(ctx, argv);
+
+ talloc_free(argv);
+
+ return rc;
+}
--- /dev/null
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#ifndef PROCESS_H
+#define PROCESS_H
+
+#include <stdbool.h>
+#include <sys/types.h>
+
+#include <list/list.h>
+#include <waiter/waiter.h>
+
+struct process;
+struct procset;
+
+typedef void (*process_exit_cb)(struct process *);
+
+struct process {
+ /* caller-provided configuration */
+ const char *path;
+ const char **argv;
+ bool keep_stdout;
+ process_exit_cb exit_cb;
+ void *data;
+
+ /* runtime data */
+ pid_t pid;
+ int stdout_len;
+ char *stdout_buf;
+
+ /* post-execution information */
+ int exit_status;
+};
+
+/* Process management system init. process_init must be called before
+ * process_create. The pointer returned can be talloc_free()-ed, or can be
+ * automatically freed through destruction of the ctx talloc tree.
+ */
+struct procset *process_init(void *ctx, struct waitset *set);
+
+struct process *process_create(void *ctx);
+
+/* process_release: release our reference to the process, but potentially
+ * leave it running. When the process exits, associated resources will
+ * be deallocated.
+ */
+void process_release(struct process *process);
+
+/* Synchronous interface. These functions will all block while waiting for
+ * the process to exit.
+ */
+int process_run_sync(struct process *process);
+int process_run_simple_argv(void *ctx, const char *argv[]);
+int process_run_simple(void *ctx, const char *name, ...)
+ __attribute__((sentinel(0)));
+
+/* Asynchronous interface. When a process is run with process_run_async, the
+ * function returns without wait()ing for the child process to exit. If the
+ * process' exit_cb member is set, that callback will be invoked when the
+ * process exits.
+ */
+int process_run_async(struct process *process);
+
+void process_stop_async(struct process *process);
+#endif /* PROCESS_H */
projects / petitboot / commitdiff