1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
/*
watchquagga CLI functions.
Copyright (C) 2016 David Lamparter for NetDEF, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <zebra.h>
#include <sys/wait.h>
#include "memory.h"
#include "log.h"
#include "vty.h"
#include "command.h"
#include "watchquagga.h"
pid_t integrated_write_pid;
static int integrated_result_fd;
DEFUN (config_write_integrated,
config_write_integrated_cmd,
"write integrated",
"Write running configuration to memory, network, or terminal\n"
"Write integrated all-daemon Quagga.conf file\n")
{
pid_t child;
sigset_t oldmask, sigmask;
if (integrated_write_pid != -1) {
vty_out(vty, "%% configuration write already in progress.%s",
VTY_NEWLINE);
return CMD_WARNING;
}
fflush(stdout);
fflush(stderr);
/* need to temporarily block SIGCHLD because it could arrive between
* fork() call and setting the integrated_write_pid variable. This
* would mean the completion call gets lost and this hangs forever.
*/
sigemptyset(&oldmask);
sigemptyset(&sigmask);
sigaddset(&sigmask, SIGCHLD);
sigprocmask(SIG_BLOCK, &sigmask, &oldmask);
child = fork();
if (child == -1) {
vty_out(vty, "%% configuration write fork() failed: %s.%s",
safe_strerror(errno), VTY_NEWLINE);
sigprocmask(SIG_SETMASK, &oldmask, NULL);
return CMD_WARNING;
}
if (child != 0) {
/* note: the VTY won't write a command return value to vtysh; the
* session temporarily enters an intentional "hang" state. This is
* to make sure latency in vtysh doing the config write (several
* seconds is not rare to see) does not interfere with watchquagga's
* supervisor job.
*
* The fd is duplicated here so we don't need to hold a vty pointer
* (which could become invalid in the meantime).
*/
integrated_write_pid = child;
integrated_result_fd = dup(vty->wfd);
sigprocmask(SIG_SETMASK, &oldmask, NULL);
return CMD_SUSPEND;
}
/* redirect stdout/stderr to vty session. Note vty->wfd is marked
* CLOEXEC, but dup2 will clear that flag. */
dup2(vty->wfd, 1);
dup2(vty->wfd, 2);
/* don't allow the user to pass parameters, we're root here!
* should probably harden vtysh at some point too... */
execl(VTYSH_BIN_PATH, "vtysh", "-w", NULL);
/* unbuffered write; we just messed with stdout... */
char msg[512];
snprintf(msg, sizeof(msg), "error executing %s: %s\n",
VTYSH_BIN_PATH, safe_strerror(errno));
write(1, msg, strlen(msg));
exit(1);
}
void integrated_write_sigchld(int status)
{
uint8_t reply[4] = { 0, 0, 0, CMD_WARNING };
if (WIFEXITED(status)) {
zlog_info("configuration write completed with exit code %d",
WEXITSTATUS(status));
reply[3] = WEXITSTATUS(status);
} else if (WIFSIGNALED(status)) {
zlog_warn("configuration write terminated by signal %d",
WTERMSIG(status));
} else {
zlog_warn("configuration write terminated");
}
if (reply[3] != CMD_SUCCESS) {
/* failure might be silent in vtysh without this */
static const char msg[] = "% Configuration write failed.\n";
write(integrated_result_fd, msg, strlen(msg));
}
/* don't care about failures here, if the connection is broken the
* return value will just be lost. */
write(integrated_result_fd, reply, sizeof(reply));
close(integrated_result_fd);
integrated_write_pid = -1;
}
void watchquagga_vty_init(void)
{
integrated_write_pid = -1;
install_element(ENABLE_NODE, &config_write_integrated_cmd);
}
|
