Return to edit.c CVS log

Up to [local] / src / usr.bin / mail

Prevent edit'ing a message from corrupting the mailbox. In an mbox file
every message is terminated by an empty line, so we have to make sure it
is preserved. Otherwise the message is combined with the next one.

joint effort with deraadt and millert

/*	$OpenBSD: edit.c,v 1.20 2017/03/28 09:14:43 natano Exp $	*/
/*	$NetBSD: edit.c,v 1.5 1996/06/08 19:48:20 christos Exp $	*/

/*
 * 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 <sys/types.h>
#include <sys/wait.h>

#include "rcv.h"
#include <errno.h>
#include <fcntl.h>
#include "extern.h"

int editit(const char *, const char *);

/*
 * Mail -- a mail program
 *
 * Perform message editing functions.
 */

/*
 * Edit a message list.
 */
int
editor(void *v)
{
	int *msgvec = v;

	return(edit1(msgvec, 'e'));
}

/*
 * Invoke the visual editor on a message list.
 */
int
visual(void *v)
{
	int *msgvec = v;

	return(edit1(msgvec, 'v'));
}

/*
 * Edit a message by writing the message into a funnily-named file
 * (which should not exist) and forking an editor on it.
 * We get the editor from the stuff above.
 */
int
edit1(int *msgvec, int type)
{
	int nl = 0, c, i;
	FILE *fp;
	struct sigaction oact;
	sigset_t oset;
	struct message *mp;
	off_t size;

	/*
	 * Deal with each message to be edited . . .
	 */
	for (i = 0; msgvec[i] && i < msgCount; i++) {
		if (i > 0) {
			char buf[100];
			char *p;

			printf("Edit message %d [ynq]? ", msgvec[i]);
			if (fgets(buf, sizeof(buf), stdin) == NULL)
				break;
			for (p = buf; *p == ' ' || *p == '\t'; p++)
				;
			if (*p == 'q')
				break;
			if (*p == 'n')
				continue;
		}
		dot = mp = &message[msgvec[i] - 1];
		touch(mp);
		(void)ignoresig(SIGINT, &oact, &oset);
		fp = run_editor(setinput(mp), (off_t)mp->m_size, type, readonly);
		if (fp != NULL) {
			(void)fseek(otf, 0L, SEEK_END);
			size = ftell(otf);
			mp->m_block = blockof(size);
			mp->m_offset = offsetof(size);
			mp->m_size = fsize(fp);
			mp->m_lines = 0;
			mp->m_flag |= MODIFY;
			rewind(fp);
			while ((c = getc(fp)) != EOF) {
				if (c == '\n') {
					mp->m_lines++;
					nl++;
				} else
					nl = 0;
				if (putc(c, otf) == EOF)
					break;
			}
			for (; nl < 2; nl++) {
				mp->m_lines++;
				mp->m_size++;
				putc('\n', otf);
			}
			if (ferror(otf))
				warn("%s", tmpdir);
			(void)Fclose(fp);
		}
		(void)sigprocmask(SIG_SETMASK, &oset, NULL);
		(void)sigaction(SIGINT, &oact, NULL);
	}
	return(0);
}

/*
 * Run an editor on the file at "fpp" of "size" bytes,
 * and return a new file pointer.
 * Signals must be handled by the caller.
 * "Type" is 'e' for _PATH_EX, 'v' for _PATH_VI.
 */
FILE *
run_editor(FILE *fp, off_t size, int type, int readonly)
{
	FILE *nf = NULL;
	int t;
	time_t modtime;
	char *edit, tempname[PATHSIZE];
	struct stat statb;

	(void)snprintf(tempname, sizeof(tempname),
	    "%s/mail.ReXXXXXXXXXX", tmpdir);
	if ((t = mkstemp(tempname)) == -1 ||
	    (nf = Fdopen(t, "w")) == NULL) {
		warn("%s", tempname);
		goto out;
	}
	if (readonly && fchmod(t, 0400) == -1) {
		warn("%s", tempname);
		(void)rm(tempname);
		goto out;
	}
	if (size >= 0)
		while (--size >= 0 && (t = getc(fp)) != EOF)
			(void)putc(t, nf);
	else
		while ((t = getc(fp)) != EOF)
			(void)putc(t, nf);
	(void)fflush(nf);
	if (fstat(fileno(nf), &statb) < 0)
		modtime = 0;
	else
		modtime = statb.st_mtime;
	if (ferror(nf)) {
		(void)Fclose(nf);
		warn("%s", tempname);
		(void)rm(tempname);
		nf = NULL;
		goto out;
	}
	if (Fclose(nf) < 0) {
		warn("%s", tempname);
		(void)rm(tempname);
		nf = NULL;
		goto out;
	}
	nf = NULL;
	if (type == 'e') {
		edit = value("EDITOR");
		if (edit == NULL || edit[0] == '\0')
			edit = _PATH_EX;
	} else {
		edit = value("VISUAL");
		if (edit == NULL || edit[0] == '\0')
			edit = _PATH_VI;
	}
	if (editit(edit, tempname) == -1) {
		(void)rm(tempname);
		goto out;
	}
	/*
	 * If in read only mode or file unchanged, just remove the editor
	 * temporary and return.
	 */
	if (readonly) {
		(void)rm(tempname);
		goto out;
	}
	if (stat(tempname, &statb) < 0) {
		warn("%s", tempname);
		goto out;
	}
	if (modtime == statb.st_mtime) {
		(void)rm(tempname);
		goto out;
	}
	/*
	 * Now switch to new file.
	 */
	if ((nf = Fopen(tempname, "a+")) == NULL) {
		warn("%s", tempname);
		(void)rm(tempname);
		goto out;
	}
	(void)rm(tempname);
out:
	return(nf);
}

/*
 * Execute an editor on the specified pathname, which is interpreted
 * from the shell.  This means flags may be included.
 *
 * Returns -1 on error, or the exit value on success.
 */
int
editit(const char *ed, const char *pathname)
{
	char *argp[] = {"sh", "-c", NULL, NULL}, *p;
	sig_t sighup, sigint, sigquit, sigchld;
	pid_t pid;
	int saved_errno, st, ret = -1;

	if (ed == NULL)
		ed = getenv("VISUAL");
	if (ed == NULL || ed[0] == '\0')
		ed = getenv("EDITOR");
	if (ed == NULL || ed[0] == '\0')
		ed = _PATH_VI;
	if (asprintf(&p, "%s %s", ed, pathname) == -1)
		return (-1);
	argp[2] = p;

	sighup = signal(SIGHUP, SIG_IGN);
	sigint = signal(SIGINT, SIG_IGN);
	sigquit = signal(SIGQUIT, SIG_IGN);
	sigchld = signal(SIGCHLD, SIG_DFL);
	if ((pid = fork()) == -1)
		goto fail;
	if (pid == 0) {
		execv(_PATH_BSHELL, argp);
		_exit(127);
	}
	while (waitpid(pid, &st, 0) == -1)
		if (errno != EINTR)
			goto fail;
	if (!WIFEXITED(st))
		errno = EINTR;
	else
		ret = WEXITSTATUS(st);

 fail:
	saved_errno = errno;
	(void)signal(SIGHUP, sighup);
	(void)signal(SIGINT, sigint);
	(void)signal(SIGQUIT, sigquit);
	(void)signal(SIGCHLD, sigchld);
	free(p);
	errno = saved_errno;
	return (ret);
}