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Merge pull request #29127 from YHNdnzj/wall-followup

shared/wall: several cleanups
This commit is contained in:
Luca Boccassi
2023-09-09 01:30:51 +01:00
committed by GitHub
4 changed files with 94 additions and 55 deletions

4
TODO
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@ -2466,3 +2466,7 @@ Features:
- some servers don't do rapid commit without a filled in IA_NA, verify
this behavior
- RouteTable= ?
* shared/wall: Once more programs are taught to prefer sd-login over utmp,
switch the default wall implementation to wall_logind
(https://github.com/systemd/systemd/pull/29051#issuecomment-1704917074)

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@ -1,8 +1,6 @@
/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
@ -13,14 +11,11 @@
#include "alloc-util.h"
#include "errno-util.h"
#include "fd-util.h"
#include "hostname-util.h"
#include "io-util.h"
#include "macro.h"
#include "memory-util.h"
#include "path-util.h"
#include "string-util.h"
#include "terminal-util.h"
#include "time-util.h"
#include "user-util.h"
#include "utmp-wtmp.h"

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@ -17,6 +17,8 @@
#include "utmp-wtmp.h"
#include "wall.h"
#if ENABLE_UTMP || ENABLE_LOGIND
#define TIMEOUT_USEC (50 * USEC_PER_MSEC)
static int write_to_terminal(const char *tty, const char *message) {
@ -34,97 +36,107 @@ static int write_to_terminal(const char *tty, const char *message) {
return loop_write_full(fd, message, SIZE_MAX, TIMEOUT_USEC);
}
#if ENABLE_UTMP
static int do_wall(
static int wall_utmp(
const char *message,
const char *username,
const char *origin_tty,
bool (*match_tty)(const char *tty, bool is_local, void *userdata),
void *userdata) {
#if ENABLE_UTMP
_unused_ _cleanup_(utxent_cleanup) bool utmpx = false;
struct utmpx *u;
int r;
int r = 0;
assert(message);
/* libc's setutxent() unfortunately doesn't inform us about success, i.e. whether /var/run/utmp
* exists. Hence we have to check manually first. */
if (access(_PATH_UTMPX, F_OK) < 0) {
if (errno == ENOENT)
return -ENOPROTOOPT;
return -errno;
}
utmpx = utxent_start();
r = 0;
while ((u = getutxent())) {
_cleanup_free_ char *buf = NULL;
const char *path;
int q;
_cleanup_free_ char *p = NULL;
const char *tty_path;
bool is_local;
if (u->ut_type != USER_PROCESS || u->ut_user[0] == 0)
if (u->ut_type != USER_PROCESS || isempty(u->ut_user))
continue;
/* This access is fine, because strlen("/dev/") < 32 (UT_LINESIZE) */
if (path_startswith(u->ut_line, "/dev/"))
path = u->ut_line;
tty_path = u->ut_line;
else {
if (asprintf(&buf, "/dev/%.*s", (int) sizeof(u->ut_line), u->ut_line) < 0)
if (asprintf(&p, "/dev/%.*s", (int) sizeof(u->ut_line), u->ut_line) < 0)
return -ENOMEM;
path = buf;
tty_path = p;
}
/* It seems that the address field is always set for remote logins.
* For local logins and other local entries, we get [0,0,0,0]. */
bool is_local = memeqzero(u->ut_addr_v6, sizeof(u->ut_addr_v6));
/* It seems that the address field is always set for remote logins. For local logins and
* other local entries, we get [0,0,0,0]. */
is_local = eqzero(u->ut_addr_v6);
if (!match_tty || match_tty(path, is_local, userdata)) {
q = write_to_terminal(path, message);
if (q < 0)
r = q;
}
if (!match_tty || match_tty(tty_path, is_local, userdata))
RET_GATHER(r, write_to_terminal(tty_path, message));
}
return r;
}
#else
return -ENOPROTOOPT;
#endif
}
static int do_wall(
static int wall_logind(
const char *message,
const char *username,
const char *origin_tty,
bool (*match_tty)(const char *tty, bool is_local, void *userdata),
void *userdata) {
int r;
#if ENABLE_LOGIND
_cleanup_strv_free_ char **sessions = NULL;
int r;
assert(message);
r = sd_get_sessions(&sessions);
if (r < 0)
if (r <= 0)
return r;
r = 0;
STRV_FOREACH(s, sessions) {
_cleanup_free_ char *path = NULL, *tty = NULL, *rhost = NULL;
_cleanup_free_ char *tty_path = NULL, *tty = NULL, *rhost = NULL;
bool is_local;
int q;
q = sd_session_get_tty(*s, &tty);
if (q < 0) {
if (q != -ENXIO && q != -ENODATA)
r = q;
if (IN_SET(q, -ENXIO, -ENODATA))
continue;
}
if (q < 0)
return RET_GATHER(r, q);
path = strjoin("/dev/", tty);
if (!path)
tty_path = strjoin("/dev/", tty);
if (!tty_path)
return -ENOMEM;
(void) sd_session_get_remote_host(*s, &rhost);
bool is_local = !rhost;
is_local = !rhost;
if (!match_tty || match_tty(path, is_local, userdata)) {
q = write_to_terminal(path, message);
if (q < 0)
r = q;
}
if (!match_tty || match_tty(tty_path, is_local, userdata))
RET_GATHER(r, write_to_terminal(tty_path, message));
}
return r;
}
return r;
#else
return -ENOPROTOOPT;
#endif
}
int wall(
const char *message,
@ -133,15 +145,21 @@ int wall(
bool (*match_tty)(const char *tty, bool is_local, void *userdata),
void *userdata) {
_cleanup_free_ char *text = NULL, *hn = NULL, *un = NULL, *stdin_tty = NULL;
_cleanup_free_ char *text = NULL, *hostname = NULL, *username_alloc = NULL, *stdin_tty = NULL;
int r;
hn = gethostname_malloc();
if (!hn)
assert(message);
hostname = gethostname_malloc();
if (!hostname)
return -ENOMEM;
if (!username) {
un = getlogname_malloc();
if (!un)
username_alloc = getlogname_malloc();
if (!username_alloc)
return -ENOMEM;
username = username_alloc;
}
if (!origin_tty) {
@ -153,11 +171,17 @@ int wall(
"\r\n"
"Broadcast message from %s@%s%s%s (%s):\r\n\r\n"
"%s\r\n\r\n",
un ?: username, hn,
username, hostname,
origin_tty ? " on " : "", strempty(origin_tty),
FORMAT_TIMESTAMP(now(CLOCK_REALTIME)),
message) < 0)
return -ENOMEM;
return do_wall(text, username, origin_tty, match_tty, userdata);
r = wall_utmp(text, match_tty, userdata);
if (r == -ENOPROTOOPT)
r = wall_logind(text, match_tty, userdata);
return r == -ENOPROTOOPT ? 0 : r;
}
#endif

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@ -3,9 +3,25 @@
#include <stdbool.h>
#if ENABLE_UTMP || ENABLE_LOGIND
int wall(
const char *message,
const char *username,
const char *origin_tty,
bool (*match_tty)(const char *tty, bool is_local, void *userdata),
void *userdata);
#else
static inline int wall(
const char *message,
const char *username,
const char *origin_tty,
bool (*match_tty)(const char *tty, bool is_local, void *userdata),
void *userdata) {
return 0;
}
#endif