1 files changed, 406 insertions, 0 deletions
diff --git a/usr.bin/mail/popen.c b/usr.bin/mail/popen.c
new file mode 100644
index 000000000000..69326bdb260c
--- /dev/null
+++ b/usr.bin/mail/popen.c
@@ -0,0 +1,406 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1980, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "rcv.h"
+#include <sys/wait.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdarg.h>
+#include "extern.h"
+
+#define READ 0
+#define WRITE 1
+
+struct fp {
+	FILE	*fp;
+	int	pipe;
+	pid_t	pid;
+	struct	fp *link;
+};
+static struct fp *fp_head;
+
+struct child {
+	pid_t	pid;
+	char	done;
+	char	free;
+	int	status;
+	struct	child *link;
+};
+static struct child *child, *child_freelist = NULL;
+
+static void delchild(struct child *);
+static pid_t file_pid(FILE *);
+static pid_t start_commandv(char *, sigset_t *, int, int, va_list);
+
+FILE *
+Fopen(const char *path, const char *mode)
+{
+	FILE *fp;
+
+	if ((fp = fopen(path, mode)) != NULL) {
+		register_file(fp, 0, 0);
+		(void)fcntl(fileno(fp), F_SETFD, 1);
+	}
+	return (fp);
+}
+
+FILE *
+Fdopen(int fd, const char *mode)
+{
+	FILE *fp;
+
+	if ((fp = fdopen(fd, mode)) != NULL) {
+		register_file(fp, 0, 0);
+		(void)fcntl(fileno(fp), F_SETFD, 1);
+	}
+	return (fp);
+}
+
+int
+Fclose(FILE *fp)
+{
+
+	unregister_file(fp);
+	return (fclose(fp));
+}
+
+FILE *
+Popen(char *cmd, const char *mode)
+{
+	int p[2];
+	int myside, hisside, fd0, fd1;
+	pid_t pid;
+	sigset_t nset;
+	FILE *fp;
+
+	if (pipe(p) < 0)
+		return (NULL);
+	(void)fcntl(p[READ], F_SETFD, 1);
+	(void)fcntl(p[WRITE], F_SETFD, 1);
+	if (*mode == 'r') {
+		myside = p[READ];
+		hisside = fd0 = fd1 = p[WRITE];
+	} else {
+		myside = p[WRITE];
+		hisside = fd0 = p[READ];
+		fd1 = -1;
+	}
+	(void)sigemptyset(&nset);
+	pid = start_command(value("SHELL"), &nset, fd0, fd1, "-c", cmd, NULL);
+	if (pid < 0) {
+		(void)close(p[READ]);
+		(void)close(p[WRITE]);
+		return (NULL);
+	}
+	(void)close(hisside);
+	if ((fp = fdopen(myside, mode)) != NULL)
+		register_file(fp, 1, pid);
+	return (fp);
+}
+
+int
+Pclose(FILE *ptr)
+{
+	int i;
+	sigset_t nset, oset;
+
+	i = file_pid(ptr);
+	unregister_file(ptr);
+	(void)fclose(ptr);
+	(void)sigemptyset(&nset);
+	(void)sigaddset(&nset, SIGINT);
+	(void)sigaddset(&nset, SIGHUP);
+	(void)sigprocmask(SIG_BLOCK, &nset, &oset);
+	i = wait_child(i);
+	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
+	return (i);
+}
+
+void
+close_all_files(void)
+{
+
+	while (fp_head != NULL)
+		if (fp_head->pipe)
+			(void)Pclose(fp_head->fp);
+		else
+			(void)Fclose(fp_head->fp);
+}
+
+void
+register_file(FILE *fp, int pipe, pid_t pid)
+{
+	struct fp *fpp;
+
+	if ((fpp = malloc(sizeof(*fpp))) == NULL)
+		err(1, "Out of memory");
+	fpp->fp = fp;
+	fpp->pipe = pipe;
+	fpp->pid = pid;
+	fpp->link = fp_head;
+	fp_head = fpp;
+}
+
+void
+unregister_file(FILE *fp)
+{
+	struct fp **pp, *p;
+
+	for (pp = &fp_head; (p = *pp) != NULL; pp = &p->link)
+		if (p->fp == fp) {
+			*pp = p->link;
+			(void)free(p);
+			return;
+		}
+	errx(1, "Invalid file pointer");
+	/*NOTREACHED*/
+}
+
+pid_t
+file_pid(FILE *fp)
+{
+	struct fp *p;
+
+	for (p = fp_head; p != NULL; p = p->link)
+		if (p->fp == fp)
+			return (p->pid);
+	errx(1, "Invalid file pointer");
+	/*NOTREACHED*/
+}
+
+/*
+ * Run a command without a shell, with optional arguments and splicing
+ * of stdin (-1 means none) and stdout.  The command name can be a sequence
+ * of words.
+ * Signals must be handled by the caller.
+ * "nset" contains the signals to ignore in the new process.
+ * SIGINT is enabled unless it's in "nset".
+ */
+static pid_t
+start_commandv(char *cmd, sigset_t *nset, int infd, int outfd, va_list args)
+{
+	pid_t pid;
+
+	if ((pid = fork()) < 0) {
+		warn("fork");
+		return (-1);
+	}
+	if (pid == 0) {
+		char *argv[100];
+		int i = getrawlist(cmd, argv, sizeof(argv) / sizeof(*argv));
+
+		while ((argv[i++] = va_arg(args, char *)))
+			;
+		argv[i] = NULL;
+		prepare_child(nset, infd, outfd);
+		execvp(argv[0], argv);
+		warn("%s", argv[0]);
+		_exit(1);
+	}
+	return (pid);
+}
+
+int
+run_command(char *cmd, sigset_t *nset, int infd, int outfd, ...)
+{
+	pid_t pid;
+	va_list args;
+
+	va_start(args, outfd);
+	pid = start_commandv(cmd, nset, infd, outfd, args);
+	va_end(args);
+	if (pid < 0)
+		return -1;
+	return wait_command(pid);
+}
+
+int
+start_command(char *cmd, sigset_t *nset, int infd, int outfd, ...)
+{
+	va_list args;
+	int r;
+
+	va_start(args, outfd);
+	r = start_commandv(cmd, nset, infd, outfd, args);
+	va_end(args);
+	return r;
+}
+
+void
+prepare_child(sigset_t *nset, int infd, int outfd)
+{
+	int i;
+	sigset_t eset;
+
+	/*
+	 * All file descriptors other than 0, 1, and 2 are supposed to be
+	 * close-on-exec.
+	 */
+	if (infd >= 0)
+		dup2(infd, 0);
+	if (outfd >= 0)
+		dup2(outfd, 1);
+	for (i = 1; i < NSIG; i++)
+		if (nset != NULL && sigismember(nset, i))
+			(void)signal(i, SIG_IGN);
+	if (nset == NULL || !sigismember(nset, SIGINT))
+		(void)signal(SIGINT, SIG_DFL);
+	(void)sigemptyset(&eset);
+	(void)sigprocmask(SIG_SETMASK, &eset, NULL);
+}
+
+int
+wait_command(pid_t pid)
+{
+
+	if (wait_child(pid) < 0) {
+		printf("Fatal error in process.\n");
+		return (-1);
+	}
+	return (0);
+}
+
+static struct child *
+findchild(pid_t pid, int dont_alloc)
+{
+	struct child **cpp;
+
+	for (cpp = &child; *cpp != NULL && (*cpp)->pid != pid;
+	    cpp = &(*cpp)->link)
+			;
+	if (*cpp == NULL) {
+		if (dont_alloc)
+			return(NULL);
+		if (child_freelist) {
+			*cpp = child_freelist;
+			child_freelist = (*cpp)->link;
+		} else {
+			*cpp = malloc(sizeof(struct child));
+			if (*cpp == NULL)
+				err(1, "malloc");
+		}
+		(*cpp)->pid = pid;
+		(*cpp)->done = (*cpp)->free = 0;
+		(*cpp)->link = NULL;
+	}
+	return (*cpp);
+}
+
+static void
+delchild(struct child *cp)
+{
+	struct child **cpp;
+
+	for (cpp = &child; *cpp != cp; cpp = &(*cpp)->link)
+		;
+	*cpp = cp->link;
+	cp->link = child_freelist;
+	child_freelist = cp;
+}
+
+/*ARGSUSED*/
+void
+sigchild(int signo __unused)
+{
+	pid_t pid;
+	int status;
+	struct child *cp;
+	int save_errno;
+
+	save_errno = errno;
+	while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
+		cp = findchild(pid, 1);
+		if (cp == NULL)
+			continue;
+		if (cp->free)
+			delchild(cp);
+		else {
+			cp->done = 1;
+			cp->status = status;
+		}
+	}
+	errno = save_errno;
+}
+
+int wait_status;
+
+/*
+ * Wait for a specific child to die.
+ */
+int
+wait_child(pid_t pid)
+{
+	struct child *cp;
+	sigset_t nset, oset;
+	pid_t rv = 0;
+
+	(void)sigemptyset(&nset);
+	(void)sigaddset(&nset, SIGCHLD);
+	(void)sigprocmask(SIG_BLOCK, &nset, &oset);
+	/*
+	 * If we have not already waited on the pid (via sigchild)
+	 * wait on it now.  Otherwise, use the wait status stashed
+	 * by sigchild.
+	 */
+	cp = findchild(pid, 1);
+	if (cp == NULL || !cp->done)
+		rv = waitpid(pid, &wait_status, 0);
+	else
+		wait_status = cp->status;
+	if (cp != NULL)
+		delchild(cp);
+	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
+	if (rv == -1 || (WIFEXITED(wait_status) && WEXITSTATUS(wait_status)))
+		return -1;
+	else
+		return 0;
+}
+
+/*
+ * Mark a child as don't care.
+ */
+void
+free_child(pid_t pid)
+{
+	struct child *cp;
+	sigset_t nset, oset;
+
+	(void)sigemptyset(&nset);
+	(void)sigaddset(&nset, SIGCHLD);
+	(void)sigprocmask(SIG_BLOCK, &nset, &oset);
+	if ((cp = findchild(pid, 0)) != NULL) {
+		if (cp->done)
+			delchild(cp);
+		else
+			cp->free = 1;
+	}
+	(void)sigprocmask(SIG_SETMASK, &oset, NULL);
+}