xref: /openbsd-src/usr.sbin/syslogc/syslogc.c (revision 5b27f6176eca0ef8066a6d4eb65362ceed3f3ed7)
1 /* $OpenBSD: syslogc.c,v 1.6 2004/06/25 19:11:38 djm 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 <errno.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <unistd.h>
29 
30 #define DEFAULT_CTLSOCK		"/var/run/syslogd.sock"
31 
32 #define MAX_MEMBUF_NAME	64	/* Max length of membuf log name */
33 
34 /*
35  * Client protocol NB. all numeric fields in network byte order
36  */
37 #define CTL_VERSION		0
38 
39 /* Request */
40 struct ctl_cmd {
41 	u_int32_t	version;
42 #define CMD_READ	1	/* Read out log */
43 #define CMD_READ_CLEAR	2	/* Read and clear log */
44 #define CMD_CLEAR	3	/* Clear log */
45 #define CMD_LIST	4	/* List available logs */
46 #define CMD_FLAGS	5	/* Query flags only */
47 	u_int32_t	cmd;
48 	char		logname[MAX_MEMBUF_NAME];
49 };
50 
51 /* Reply */
52 struct ctl_reply_hdr {
53 	u_int32_t	version;
54 #define CTL_HDR_FLAG_OVERFLOW	0x01
55 	u_int32_t	flags;
56 	/* Reply text follows, up to MAX_MEMBUF long */
57 };
58 
59 /* Protocol parameters - must match syslogd */
60 #define CTL_VERSION		0
61 #define CTL_HDR_LEN		8
62 
63 static void
64 usage(void)
65 {
66 	extern char *__progname;
67 
68 	fprintf(stderr, "Usage: %s [-Ccq] [-s ctlsock] logname\n", __progname);
69 	exit(1);
70 }
71 
72 int
73 main(int argc, char **argv)
74 {
75 	const char *ctlsock_path;
76 	char buf[8192];
77 	struct sockaddr_un ctl;
78 	socklen_t ctllen;
79 	int ctlsock, ch, oflag, rval;
80 	FILE *ctlf;
81 	extern char *optarg;
82 	extern int optind;
83 	struct ctl_cmd cc;
84 	struct ctl_reply_hdr rr;
85 	u_int32_t header[2];
86 
87 	memset(&cc, '\0', sizeof(cc));
88 
89 	ctlsock_path = DEFAULT_CTLSOCK;
90 	rval = oflag = 0;
91 	while ((ch = getopt(argc, argv, "Cchoqs:")) != -1) {
92 		switch (ch) {
93 		case 'C':
94 			cc.cmd = CMD_CLEAR;
95 			break;
96 		case 'c':
97 			cc.cmd = CMD_READ_CLEAR;
98 			break;
99 		case 'h':
100 			usage();
101 			break;
102 		case 'o':
103 			cc.cmd = CMD_FLAGS;
104 			oflag = 1;
105 			break;
106 		case 'q':
107 			cc.cmd = CMD_LIST;
108 			break;
109 		case 's':
110 			ctlsock_path = optarg;
111 			break;
112 		default:
113 			fprintf(stderr, "Invalid commandline option.\n");
114 			usage();
115 			break;
116 		}
117 	}
118 
119 	if (cc.cmd == 0)
120 		cc.cmd = CMD_READ;
121 
122 	if ((cc.cmd != CMD_LIST && optind != argc - 1) ||
123 	    (cc.cmd == CMD_LIST && optind != argc))
124 		usage();
125 
126 	if (cc.cmd != CMD_LIST) {
127 		if (strlcpy(cc.logname, argv[optind], sizeof(cc.logname)) >=
128 		    sizeof(cc.logname))
129 			errx(1, "Specified log name is too long");
130 	}
131 
132 	memset(&ctl, '\0', sizeof(ctl));
133 	strlcpy(ctl.sun_path, ctlsock_path, sizeof(ctl.sun_path));
134 	ctl.sun_family = AF_UNIX;
135 
136 	if ((ctlsock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
137 		err(1, "socket");
138 	if (connect(ctlsock, (struct sockaddr*)&ctl, sizeof(ctl)) == -1)
139 		err(1, "connect: %s", ctl.sun_path);
140 	if ((ctlf = fdopen(ctlsock, "r+")) == NULL)
141 		err(1, "fdopen");
142 
143 	cc.version = htonl(CTL_VERSION);
144 	cc.cmd = htonl(cc.cmd);
145 	/* Send command */
146 	if (fwrite(&cc, sizeof(cc), 1, ctlf) != 1)
147 		err(1, "fwrite");
148 
149 	fflush(ctlf);
150 	setlinebuf(ctlf);
151 
152 	/* Fetch header */
153 	if (fread(&rr, sizeof(rr), 1, ctlf) != 1)
154 		err(1, "fread header");
155 
156 	if (ntohl(rr.version) != CTL_VERSION)
157 		err(1, "unsupported syslogd version");
158 
159 	/* Write out reply */
160 	while((fgets(buf, sizeof(buf), ctlf)) != NULL)
161 		fputs(buf, stdout);
162 
163 	if (oflag && (ntohl(rr.flags) & CTL_HDR_FLAG_OVERFLOW)) {
164 		printf("%s has overflowed\n", cc.logname);
165 		rval = 1;
166 	}
167 
168 	fclose(ctlf);
169 	close(ctlsock);
170 
171 	exit(rval);
172 }
173