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-rw-r--r--term-utils/write.c81
1 files changed, 38 insertions, 43 deletions
diff --git a/term-utils/write.c b/term-utils/write.c
index 1b476473f..be91218cf 100644
--- a/term-utils/write.c
+++ b/term-utils/write.c
@@ -64,6 +64,7 @@
#include "closestream.h"
#include "nls.h"
#include "strutils.h"
+#include "ttyutils.h"
#include "xalloc.h"
static sig_atomic_t signal_received = 0;
@@ -71,9 +72,11 @@ static sig_atomic_t signal_received = 0;
struct write_control {
uid_t src_uid;
const char *src_login;
- char *src_tty;
+ const char *src_tty_path;
+ const char *src_tty_name;
const char *dst_login;
- char dst_tty[PATH_MAX];
+ char *dst_tty_path;
+ const char *dst_tty_name;
};
static void __attribute__((__noreturn__)) usage(FILE *out)
@@ -98,24 +101,20 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
* check_tty - check that a terminal exists, and get the message bit
* and the access time
*/
-static int check_tty(char *tty, int *tty_writeable, time_t *tty_atime, int showerror)
+static int check_tty(const char *tty, int *tty_writeable, time_t *tty_atime, int showerror)
{
struct stat s;
- char path[PATH_MAX];
- if (sizeof(path) < strlen(tty) + 6)
- return 1;
- sprintf(path, "/dev/%s", tty);
- if (stat(path, &s) < 0) {
+ if (stat(tty, &s) < 0) {
if (showerror)
- warn("%s", path);
+ warn("%s", tty);
return 1;
}
if (getuid() == 0) /* root can always write */
*tty_writeable = 1;
else {
if (getegid() != s.st_gid) {
- warnx(_("effective gid does not match group of %s"), path);
+ warnx(_("effective gid does not match group of %s"), tty);
return 1;
}
*tty_writeable = s.st_mode & S_IWGRP;
@@ -139,7 +138,7 @@ static int check_utmp(const struct write_control *ctl)
while ((u = getutent())) {
if (strncmp(ctl->dst_login, u->ut_user, sizeof(u->ut_user)) == 0 &&
- strncmp(ctl->dst_tty, u->ut_line, sizeof(u->ut_line)) == 0) {
+ strncmp(ctl->dst_tty_name, u->ut_line, sizeof(u->ut_line)) == 0) {
res = 0;
break;
}
@@ -165,6 +164,7 @@ static void search_utmp(struct write_control *ctl)
struct utmp *u;
time_t best_atime = 0, tty_atime;
int num_ttys = 0, valid_ttys = 0, tty_writeable = 0, user_is_me = 0;
+ char path[UT_LINESIZE + 6];
utmpname(_PATH_UTMP);
setutent();
@@ -173,13 +173,14 @@ static void search_utmp(struct write_control *ctl)
if (strncmp(ctl->dst_login, u->ut_user, sizeof(u->ut_user)) != 0)
continue;
num_ttys++;
- if (check_tty(u->ut_line, &tty_writeable, &tty_atime, 0))
+ sprintf(path, "/dev/%s", u->ut_line);
+ if (check_tty(path, &tty_writeable, &tty_atime, 0))
/* bad term? skip */
continue;
if (ctl->src_uid && !tty_writeable)
/* skip ttys with msgs off */
continue;
- if (strcmp(u->ut_line, ctl->src_tty) == 0) {
+ if (strcmp(u->ut_line, ctl->src_tty_name) == 0) {
user_is_me = 1;
/* don't write to yourself */
continue;
@@ -190,8 +191,9 @@ static void search_utmp(struct write_control *ctl)
valid_ttys++;
if (best_atime < tty_atime) {
best_atime = tty_atime;
- xstrncpy(ctl->dst_tty, u->ut_line,
- sizeof(ctl->dst_tty));
+ free(ctl->dst_tty_path);
+ ctl->dst_tty_path = xstrdup(path);
+ ctl->dst_tty_name = ctl->dst_tty_path + 5;
}
}
@@ -201,14 +203,17 @@ static void search_utmp(struct write_control *ctl)
if (valid_ttys == 0) {
if (user_is_me) {
/* ok, so write to yourself! */
- xstrncpy(ctl->dst_tty, ctl->src_tty, sizeof(ctl->dst_tty));
+ if (!ctl->src_tty_path)
+ errx(EXIT_FAILURE, _("can't find your tty's name"));
+ ctl->dst_tty_path = xstrdup(ctl->src_tty_path);
+ ctl->dst_tty_name = ctl->dst_tty_path + 5;
return;
}
errx(EXIT_FAILURE, _("%s has messages disabled"), ctl->dst_login);
}
if (1 < valid_ttys)
warnx(_("%s is logged in more than once; writing to %s"),
- ctl->dst_login, ctl->dst_tty);
+ ctl->dst_login, ctl->dst_tty_name);
}
/*
@@ -243,7 +248,7 @@ static void do_write(const struct write_control *ctl)
struct passwd *pwd;
time_t now;
struct tm *tm;
- char path[PATH_MAX], *host, line[512];
+ char *host, line[512];
struct sigaction sigact;
/* Determine our login name(s) before the we reopen() stdout */
@@ -254,11 +259,8 @@ static void do_write(const struct write_control *ctl)
if ((login = getlogin()) == NULL)
login = pwuid;
- if (sizeof(path) < strlen(ctl->dst_tty) + 6)
- errx(EXIT_FAILURE, _("tty path %s too long"), ctl->dst_tty);
- snprintf(path, sizeof(path), "/dev/%s", ctl->dst_tty);
- if ((freopen(path, "w", stdout)) == NULL)
- err(EXIT_FAILURE, "%s", path);
+ if ((freopen(ctl->dst_tty_path, "w", stdout)) == NULL)
+ err(EXIT_FAILURE, "%s", ctl->dst_tty_path);
sigact.sa_handler = signal_handler;
sigemptyset(&sigact.sa_mask);
@@ -277,10 +279,10 @@ static void do_write(const struct write_control *ctl)
printf("\r\n\a\a\a");
if (strcmp(login, pwuid))
printf(_("Message from %s@%s (as %s) on %s at %s ..."),
- login, host, pwuid, ctl->src_tty, timestamp);
+ login, host, pwuid, ctl->src_tty_name, timestamp);
else
printf(_("Message from %s@%s on %s at %s ..."),
- login, host, ctl->src_tty, timestamp);
+ login, host, ctl->src_tty_name, timestamp);
free(host);
printf("\r\n");
@@ -329,25 +331,16 @@ int main(int argc, char **argv)
else
src_fd = -1;
- if (src_fd != -1) {
- if (!(ctl.src_tty = ttyname(src_fd)))
- errx(EXIT_FAILURE,
- _("can't find your tty's name"));
- /*
- * We may have /dev/ttyN but also /dev/pts/xx. Below,
- * check_tty() will put "/dev/" in front, so remove that
- * part.
- */
- if (!strncmp(ctl.src_tty, "/dev/", 5))
- ctl.src_tty += 5;
- if (check_tty(ctl.src_tty, &tty_writeable, NULL, 1))
+ if (src_fd != -1 &&
+ get_terminal_name(src_fd, &ctl.src_tty_path, &ctl.src_tty_name, NULL) == 0) {
+ if (check_tty(ctl.src_tty_path, &tty_writeable, NULL, 1))
exit(EXIT_FAILURE);
if (!tty_writeable)
errx(EXIT_FAILURE,
_("you have write permission turned off"));
tty_writeable = 0;
} else
- ctl.src_tty = "<no tty>";
+ ctl.src_tty_name = "<no tty>";
ctl.src_uid = getuid();
@@ -361,23 +354,25 @@ int main(int argc, char **argv)
case 3:
ctl.dst_login = argv[1];
if (!strncmp(argv[2], "/dev/", 5))
- xstrncpy(ctl.dst_tty, argv[2] + 5, sizeof(ctl.dst_tty));
+ ctl.dst_tty_path = xstrdup(argv[2]);
else
- xstrncpy(ctl.dst_tty, argv[2], sizeof(ctl.dst_tty));
+ xasprintf(&ctl.dst_tty_path, "/dev/%s", argv[2]);
+ ctl.dst_tty_name = ctl.dst_tty_path + 5;
if (check_utmp(&ctl))
errx(EXIT_FAILURE,
_("%s is not logged in on %s"),
- ctl.dst_login, ctl.dst_tty);
- if (check_tty(ctl.dst_tty, &tty_writeable, NULL, 1))
+ ctl.dst_login, ctl.dst_tty_name);
+ if (check_tty(ctl.dst_tty_path, &tty_writeable, NULL, 1))
exit(EXIT_FAILURE);
if (ctl.src_uid && !tty_writeable)
errx(EXIT_FAILURE,
_("%s has messages disabled on %s"),
- ctl.dst_login, ctl.dst_tty);
+ ctl.dst_login, ctl.dst_tty_name);
do_write(&ctl);
break;
default:
usage(stderr);
}
+ free(ctl.dst_tty_path);
return EXIT_SUCCESS;
}
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-05-23 10:17:47 +0200