/usr/src/usr.bin/calendar/io.c

Bug Summary

File:	src/usr.bin/calendar/io.c
Warning:	line 409, column 9 This function call is prohibited after a successful vfork

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name io.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/usr.bin/calendar/obj -resource-dir /usr/local/lib/clang/13.0.0 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/usr.bin/calendar/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c /usr/src/usr.bin/calendar/io.c

1/*	$OpenBSD: io.c,v 1.51 2021/12/07 14:00:33 robert Exp $	*/

3/*
* Copyright (c) 1989, 1993, 1994
*	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.
*/

32#include <sys/stat.h>
33#include <sys/time.h>
34#include <sys/types.h>
35#include <sys/uio.h>
36#include <sys/wait.h>

38#include <ctype.h>
39#include <err.h>
40#include <errno(*__errno()).h>
41#include <fcntl.h>
42#include <locale.h>
43#include <pwd.h>
44#include <stdio.h>
45#include <stdlib.h>
46#include <string.h>
47#include <unistd.h>
48#include <limits.h>

50#include "pathnames.h"
51#include "calendar.h"


54struct iovec header[] = {
{ "From: ", 6 },
{ NULL((void *)0), 0 },
{ " (Reminder Service)\nTo: ", 24 },
{ NULL((void *)0), 0 },
{ "\nSubject: ", 10 },
{ NULL((void *)0), 0 },
{ "'s Calendar\nPrecedence: bulk\n",  29 },
{ "Auto-Submitted: auto-generated\n\n", 32 },
63};


66void
67cal(void)
68{
int ch, l, i, bodun = 0, bodun_maybe = 0, var, printing;
struct event *events, *cur_evt, *ev1, *tmp;
char buf[2048 + 1], *prefix = NULL((void *)0), *p;
struct match *m;
FILE *fp;

events = NULL((void *)0);
cur_evt = NULL((void *)0);
if ((fp = opencal()) == NULL((void *)0))
1
Assuming the condition is false→
2
←
Taking false branch→
return;
for (printing = 0; fgets(buf, sizeof(buf), stdin(&__sF[0])) != NULL((void *)0);) {
3
←
Assuming the condition is false→
4
←
Loop condition is false. Execution continues on line 199→
if ((p = strchr(buf, '\n')) != NULL((void *)0))
	*p = '\0';
else
	while ((ch = getchar()(!__isthreaded ? (--((&__sF[0]))->_r < 0 ? __srget(
(&__sF[0])) : (int)(*((&__sF[0]))->_p++)) : (getc)
((&__sF[0])))) != '\n' && ch != EOF(-1));
for (l = strlen(buf); l > 0 && isspace(buf[l - 1]); l--)
	;
buf[l] = '\0';
if (buf[0] == '\0')
	continue;
if (strncmp(buf, "LANG=", 5) == 0) {
	(void) setlocale(LC_ALL0, buf + 5);
	setnnames();
	if (!strcmp(buf + 5, "ru_RU.UTF-8") ||
	    !strcmp(buf + 5, "uk_UA.UTF-8") ||
	    !strcmp(buf + 5, "by_BY.UTF-8")) {
		bodun_maybe++;
		bodun = 0;
		free(prefix);
		prefix = NULL((void *)0);
	} else
		bodun_maybe = 0;
	continue;
} else if (strncmp(buf, "CALENDAR=", 9) == 0) {
	char *ep;

	if (buf[9] == '\0')
		calendar = 0;
	else if (!strcasecmp(buf + 9, "julian")) {
		calendar = JULIAN;
		errno(*__errno()) = 0;
		julian = strtoul(buf + 14, &ep, 10);
		if (buf[0] == '\0' || *ep != '\0')
			julian = 13;
		if ((errno(*__errno()) == ERANGE34 && julian == ULONG_MAX(9223372036854775807L *2UL+1UL)) ||
		    julian > 14)
			errx(1, "Julian calendar offset is too large");
	} else if (!strcasecmp(buf + 9, "gregorian"))
		calendar = GREGORIAN;
	else if (!strcasecmp(buf + 9, "lunar"))
		calendar = LUNAR;
} else if (bodun_maybe && strncmp(buf, "BODUN=", 6) == 0) {
	bodun++;
	free(prefix);
	if ((prefix = strdup(buf + 6)) == NULL((void *)0))
		err(1, NULL((void *)0));
	continue;
}
/* User defined names for special events */
if ((p = strchr(buf, '='))) {
	for (i = 0; i < NUMEV3; i++) {
		if (strncasecmp(buf, spev[i].name,
		    spev[i].nlen) == 0 &&
		    (p - buf == spev[i].nlen) &&
		    buf[spev[i].nlen + 1]) {
			p++;
			free(spev[i].uname);
			if ((spev[i].uname = strdup(p)) == NULL((void *)0))
				err(1, NULL((void *)0));
			spev[i].ulen = strlen(p);
			i = NUMEV3 + 1;
		}
	}
	if (i > NUMEV3)
		continue;
}
if (buf[0] != '\t') {
	printing = (m = isnow(buf, bodun)) ? 1 : 0;
	if ((p = strchr(buf, '\t')) == NULL((void *)0)) {
		printing = 0;
		continue;
	}
	/* Need the following to catch hardwired "variable"
	 * dates */
	if (p > buf && p[-1] == '*')
		var = 1;
	else
		var = 0;
	if (printing) {
		struct match *foo;

		ev1 = NULL((void *)0);
		while (m) {
			cur_evt = malloc(sizeof(struct event));
			if (cur_evt == NULL((void *)0))
				err(1, NULL((void *)0));

			cur_evt->when = m->when;
			snprintf(cur_evt->print_date,
			    sizeof(cur_evt->print_date), "%s%c",
			    m->print_date, (var + m->var) ? '*' : ' ');
			if (ev1) {
				cur_evt->desc = ev1->desc;
				cur_evt->ldesc = NULL((void *)0);
			} else {
				if (m->bodun && prefix) {
					if (asprintf(&cur_evt->ldesc,
					    "\t%s %s", prefix,
					    p + 1) == -1)
						err(1, NULL((void *)0));
				} else if ((cur_evt->ldesc =
				    strdup(p)) == NULL((void *)0))
					err(1, NULL((void *)0));
				cur_evt->desc = &(cur_evt->ldesc);
				ev1 = cur_evt;
			}
			insert(&events, cur_evt);
			foo = m;
			m = m->next;
			free(foo);
		}
	}
} else if (printing) {
	if (asprintf(&p, "%s\n%s", ev1->ldesc,
	    buf) == -1)
		err(1, NULL((void *)0));
	free(ev1->ldesc);
	ev1->ldesc = p;
}
}
tmp = events;
while (tmp) {
5
←
Loop condition is false. Execution continues on line 204→
(void)fprintf(fp, "%s%s\n", tmp->print_date, *(tmp->desc));
tmp = tmp->next;
}
tmp = events;
while (tmp) {
6
←
Loop condition is false. Execution continues on line 211→
events = tmp;
free(tmp->ldesc);
tmp = tmp->next;
free(events);
}
closecal(fp);
7
←
Calling 'closecal'→
212}

214int
215getfield(char *p, char **endp, int *flags)
216{
int val, var, i;
char *start, savech;

for (; !isdigit((unsigned char)*p) && !isalpha((unsigned char)*p) &&
   *p != '*' && *p != '\t'; ++p)
;
if (*p == '*') {			/* `*' is every month */
*flags |= F_ISMONTH0x01;
*endp = p+1;
return (-1);	/* means 'every month' */
}
if (isdigit((unsigned char)*p)) {
val = strtol(p, &p, 10);	/* if 0, it's failure */
for (; !isdigit((unsigned char)*p) &&
    !isalpha((unsigned char)*p) && *p != '*'; ++p)
	;
*endp = p;
return (val);
}
for (start = p; isalpha((unsigned char)*++p);)
;

/* Sunday-1 */
if (*p == '+' || *p == '-')
for(; isdigit((unsigned char)*++p); )
	;

savech = *p;
*p = '\0';

/* Month */
if ((val = getmonth(start)) != 0)
*flags |= F_ISMONTH0x01;

/* Day */
else if ((val = getday(start)) != 0) {
*flags |= F_ISDAY0x02;

/* variable weekday */
if ((var = getdayvar(start)) != 0) {
	if (var <= 5 && var >= -4)
		val += var * 10;
259#ifdef DEBUG
	printf("var: %d\n", var);
261#endif
}
}

/* Try specials (Easter, Paskha, ...) */
else {
for (i = 0; i < NUMEV3; i++) {
	if (strncasecmp(start, spev[i].name, spev[i].nlen) == 0) {
		start += spev[i].nlen;
		val = i + 1;
		i = NUMEV3 + 1;
	} else if (spev[i].uname != NULL((void *)0) &&
	    strncasecmp(start, spev[i].uname, spev[i].ulen) == 0) {
		start += spev[i].ulen;
		val = i + 1;
		i = NUMEV3 + 1;
	}
}
if (i > NUMEV3) {
	const char *errstr;

	switch (*start) {
	case '-':
	case '+':
		var = strtonum(start + 1, 0, 365, &errstr);
		if (errstr)
			return (0); /* Someone is just being silly */
		if (*start == '-')
			var = -var;
		val += (NUMEV3 + 1) * var;
		/* We add one to the matching event and multiply by
		 * (NUMEV + 1) so as not to return 0 if there's a match.
		 * val will overflow if there is an obscenely large
		 * number of special events. */
		break;
	}
	*flags |= F_SPECIAL0x08;
}
if (!(*flags & F_SPECIAL0x08)) {
	/* undefined rest */
	*p = savech;
	return (0);
}
}
for (*p = savech; !isdigit((unsigned char)*p) &&
   !isalpha((unsigned char)*p) && *p != '*' && *p != '\t'; ++p)
;
*endp = p;
return (val);
310}


313FILE *
314opencal(void)
315{
int pdes[2], fdin;
struct stat st;

/* open up calendar file as stdin */
if ((fdin = open(calendarFile, O_RDONLY0x0000)) == -1 ||
   fstat(fdin, &st) == -1 || !S_ISREG(st.st_mode)((st.st_mode & 0170000) == 0100000)) {
if (!doall) {
	char *home = getenv("HOME");
	if (home == NULL((void *)0) || *home == '\0')
		errx(1, "cannot get home directory");
	if (!(chdir(home) == 0 &&
	    chdir(calendarHome) == 0 &&
	    (fdin = open(calendarFile, O_RDONLY0x0000)) != -1))
		errx(1, "no calendar file: \"%s\" or \"~/%s/%s\"",
		    calendarFile, calendarHome, calendarFile);
}
}

if (pipe(pdes) == -1) {
close(fdin);
return (NULL((void *)0));
}
switch (vfork()) {
case -1:			/* error */
(void)close(pdes[0]);
(void)close(pdes[1]);
close(fdin);
return (NULL((void *)0));
case 0:
dup2(fdin, STDIN_FILENO0);
/* child -- set stdout to pipe input */
if (pdes[1] != STDOUT_FILENO1) {
	(void)dup2(pdes[1], STDOUT_FILENO1);
	(void)close(pdes[1]);
}
(void)close(pdes[0]);
/*
 * Set stderr to /dev/null.  Necessary so that cron does not
 * wait for cpp to finish if it's running calendar -a.
 */
if (doall) {
	int fderr;
	fderr = open(_PATH_DEVNULL"/dev/null", O_WRONLY0x0001);
	if (fderr == -1)
		_exit(0);
	(void)dup2(fderr, STDERR_FILENO2);
	(void)close(fderr);
}
execl(_PATH_CPP"/usr/libexec/cpp", "cpp", "-traditional", "-undef", "-U__GNUC__",
    "-P", "-I.", "-w", _PATH_INCLUDE"-I/usr/share/calendar", (char *)NULL((void *)0));
warn(_PATH_CPP"/usr/libexec/cpp");
_exit(1);
}
/* parent -- set stdin to pipe output */
(void)dup2(pdes[0], STDIN_FILENO0);
(void)close(pdes[0]);
(void)close(pdes[1]);

/* not reading all calendar files, just set output to stdout */
if (!doall)
return (stdout(&__sF[1]));

/* set output to a temporary file, so if no output don't send mail */
return(tmpfile());
380}

382void
383closecal(FILE *fp)
384{
struct stat sbuf;
int nread, pdes[2], status;
char buf[1024];
pid_t pid = -1;

if (!doall7.1
'doall' is not equal to 0
)
8
←
Taking false branch→
return;

(void)rewind(fp);
if (fstat(fileno(fp)(!__isthreaded ? ((fp)->_file) : (fileno)(fp)), &sbuf) || !sbuf.st_size)
9
←
Assuming '__isthreaded' is 0→
10
←
'?' condition is true→
11
←
Assuming the condition is false→
12
←
Assuming field 'st_size' is not equal to 0→
13
←
Taking false branch→
goto done;
if (pipe(pdes) == -1)
14
←
Assuming the condition is false→
15
←
Taking false branch→
goto done;
switch ((pid = vfork())) {
16
←
Control jumps to 'case 0:'  at line 403→
case -1:			/* error */
(void)close(pdes[0]);
(void)close(pdes[1]);
goto done;
case 0:
/* child -- set stdin to pipe output */
if (pdes[0] != STDIN_FILENO0) {
17
←
Assuming the condition is false→
18
←
Taking false branch→
	(void)dup2(pdes[0], STDIN_FILENO0);
	(void)close(pdes[0]);
}
(void)close(pdes[1]);
19
←
This function call is prohibited after a successful vfork
execl(_PATH_SENDMAIL"/usr/sbin/sendmail", "sendmail", "-i", "-t", "-F",
    "\"Reminder Service\"", (char *)NULL((void *)0));
warn(_PATH_SENDMAIL"/usr/sbin/sendmail");
_exit(1);
}
/* parent -- write to pipe input */
(void)close(pdes[0]);

header[1].iov_base = header[3].iov_base = pw->pw_name;
header[1].iov_len = header[3].iov_len = strlen(pw->pw_name);
writev(pdes[1], header, 8);
while ((nread = read(fileno(fp)(!__isthreaded ? ((fp)->_file) : (fileno)(fp)), buf, sizeof(buf))) > 0)
(void)write(pdes[1], buf, nread);
(void)close(pdes[1]);
424done:	(void)fclose(fp);
if (pid != -1) {
while (waitpid(pid, &status, 0) == -1) {
	if (errno(*__errno()) != EINTR4)
		break;
}
}
431}


434void
435insert(struct event **head, struct event *cur_evt)
436{
struct event *tmp, *tmp2;

if (*head) {
/* Insert this one in order */
tmp = *head;
tmp2 = NULL((void *)0);
while (tmp->next &&
    tmp->when <= cur_evt->when) {
	tmp2 = tmp;
	tmp = tmp->next;
}
if (tmp->when > cur_evt->when) {
	cur_evt->next = tmp;
	if (tmp2)
		tmp2->next = cur_evt;
	else
		*head = cur_evt;
} else {
	cur_evt->next = tmp->next;
	tmp->next = cur_evt;
}
} else {
*head = cur_evt;
cur_evt->next = NULL((void *)0);
}
462}