xref: /openbsd-src/usr.sbin/syslogc/syslogc.c (revision 8df5ec29b483c6a8e9f77118680e0b2e87e056e7)
1 /* $OpenBSD: syslogc.c,v 1.11 2005/09/28 08:49:28 stevesk Exp $ */
2 
3 /*
4  * Copyright (c) 2004 Damien Miller
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/socket.h>
21 #include <sys/un.h>
22 
23 #include <err.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <unistd.h>
28 
29 #define DEFAULT_CTLSOCK		"/var/run/syslogd.sock"
30 
31 #define MAX_MEMBUF_NAME	64	/* Max length of membuf log name */
32 
33 /*
34  * Client protocol NB. all numeric fields in network byte order
35  */
36 #define CTL_VERSION		0
37 
38 /* Request */
39 struct ctl_cmd {
40 	u_int32_t	version;
41 #define CMD_READ	1	/* Read out log */
42 #define CMD_READ_CLEAR	2	/* Read and clear log */
43 #define CMD_CLEAR	3	/* Clear log */
44 #define CMD_LIST	4	/* List available logs */
45 #define CMD_FLAGS	5	/* Query flags only */
46 	u_int32_t	cmd;
47 	char		logname[MAX_MEMBUF_NAME];
48 };
49 
50 /* Reply */
51 struct ctl_reply_hdr {
52 	u_int32_t	version;
53 #define CTL_HDR_FLAG_OVERFLOW	0x01
54 	u_int32_t	flags;
55 	/* Reply text follows, up to MAX_MEMBUF long */
56 };
57 
58 static void
59 usage(void)
60 {
61 	extern char *__progname;
62 
63 	fprintf(stderr, "Usage: %s [-Ccoq] [-s ctlsock] logname\n", __progname);
64 	exit(1);
65 }
66 
67 int
68 main(int argc, char **argv)
69 {
70 	const char *ctlsock_path;
71 	char buf[8192];
72 	struct sockaddr_un ctl;
73 	int ctlsock, ch, oflag, rval;
74 	FILE *ctlf;
75 	extern char *optarg;
76 	extern int optind;
77 	struct ctl_cmd cc;
78 	struct ctl_reply_hdr rr;
79 
80 	memset(&cc, '\0', sizeof(cc));
81 
82 	ctlsock_path = DEFAULT_CTLSOCK;
83 	rval = oflag = 0;
84 	while ((ch = getopt(argc, argv, "Cchoqs:")) != -1) {
85 		switch (ch) {
86 		case 'C':
87 			cc.cmd = CMD_CLEAR;
88 			break;
89 		case 'c':
90 			cc.cmd = CMD_READ_CLEAR;
91 			break;
92 		case 'h':
93 			usage();
94 			break;
95 		case 'o':
96 			cc.cmd = CMD_FLAGS;
97 			oflag = 1;
98 			break;
99 		case 'q':
100 			cc.cmd = CMD_LIST;
101 			break;
102 		case 's':
103 			ctlsock_path = optarg;
104 			break;
105 		default:
106 			usage();
107 			break;
108 		}
109 	}
110 
111 	if (cc.cmd == 0)
112 		cc.cmd = CMD_READ;
113 
114 	if ((cc.cmd != CMD_LIST && optind != argc - 1) ||
115 	    (cc.cmd == CMD_LIST && optind != argc))
116 		usage();
117 
118 	if (cc.cmd != CMD_LIST) {
119 		if (strlcpy(cc.logname, argv[optind], sizeof(cc.logname)) >=
120 		    sizeof(cc.logname))
121 			errx(1, "Specified log name is too long");
122 	}
123 
124 	memset(&ctl, '\0', sizeof(ctl));
125 	strlcpy(ctl.sun_path, ctlsock_path, sizeof(ctl.sun_path));
126 	ctl.sun_family = AF_UNIX;
127 
128 	if ((ctlsock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
129 		err(1, "socket");
130 	if (connect(ctlsock, (struct sockaddr *)&ctl, sizeof(ctl)) == -1)
131 		err(1, "connect: %s", ctl.sun_path);
132 	if ((ctlf = fdopen(ctlsock, "r+")) == NULL)
133 		err(1, "fdopen");
134 
135 	cc.version = htonl(CTL_VERSION);
136 	cc.cmd = htonl(cc.cmd);
137 	/* Send command */
138 	if (fwrite(&cc, sizeof(cc), 1, ctlf) != 1)
139 		err(1, "fwrite");
140 
141 	fflush(ctlf);
142 	setlinebuf(ctlf);
143 
144 	/* Fetch header */
145 	if (fread(&rr, sizeof(rr), 1, ctlf) != 1)
146 		err(1, "fread header");
147 
148 	if (ntohl(rr.version) != CTL_VERSION)
149 		errx(1, "unsupported syslogd version");
150 
151 	/* Write out reply */
152 	while ((fgets(buf, sizeof(buf), ctlf)) != NULL)
153 		fputs(buf, stdout);
154 
155 	if (oflag && (ntohl(rr.flags) & CTL_HDR_FLAG_OVERFLOW)) {
156 		printf("%s has overflowed\n", cc.logname);
157 		rval = 1;
158 	}
159 
160 	fclose(ctlf);
161 	close(ctlsock);
162 
163 	exit(rval);
164 }
165