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/* $OpenBSD: syslogc.c,v 1.18 2015/10/13 16:30:55 deraadt Exp $ */
/*
* Copyright (c) 2004 Damien Miller
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <err.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#define DEFAULT_CTLSOCK "/var/run/syslogd.sock"
#define MAX_MEMBUF_NAME 64 /* Max length of membuf log name */
/*
* Client protocol NB. all numeric fields in network byte order
*/
#define CTL_VERSION 2
/* Request */
struct ctl_cmd {
u_int32_t version;
#define CMD_READ 1 /* Read out log */
#define CMD_READ_CLEAR 2 /* Read and clear log */
#define CMD_CLEAR 3 /* Clear log */
#define CMD_LIST 4 /* List available logs */
#define CMD_FLAGS 5 /* Query flags only */
#define CMD_READ_CONT 6 /* Read out log continuously */
u_int32_t cmd;
u_int32_t lines;
char logname[MAX_MEMBUF_NAME];
};
/* Reply */
struct ctl_reply_hdr {
u_int32_t version;
#define CTL_HDR_FLAG_OVERFLOW 0x01
u_int32_t flags;
/* Reply text follows, up to MAX_MEMBUF long */
};
static void
usage(void)
{
extern char *__progname;
fprintf(stderr,
"usage: %s [-Ccfo] [-n lines] [-s reporting_socket] logname\n"
" %s -q\n", __progname, __progname);
exit(1);
}
int
main(int argc, char **argv)
{
const char *ctlsock_path;
char buf[8192];
struct sockaddr_un ctl;
int ctlsock, ch, oflag, rval;
FILE *ctlf;
extern char *optarg;
extern int optind;
struct ctl_cmd cc;
struct ctl_reply_hdr rr;
const char *errstr;
memset(&cc, '\0', sizeof(cc));
ctlsock_path = DEFAULT_CTLSOCK;
rval = oflag = 0;
while ((ch = getopt(argc, argv, "Ccfhon:qs:")) != -1) {
switch (ch) {
case 'C':
cc.cmd = CMD_CLEAR;
break;
case 'c':
cc.cmd = CMD_READ_CLEAR;
break;
case 'h':
usage();
break;
case 'f':
cc.cmd = CMD_READ_CONT;
break;
case 'n':
cc.lines = strtonum(optarg, 1, UINT32_MAX, &errstr);
if (errstr)
errx(1, "number of lines is %s: %s",
errstr, optarg);
break;
case 'o':
cc.cmd = CMD_FLAGS;
oflag = 1;
break;
case 'q':
cc.cmd = CMD_LIST;
break;
case 's':
ctlsock_path = optarg;
break;
default:
usage();
break;
}
}
if (cc.cmd == 0)
cc.cmd = CMD_READ;
if ((cc.cmd != CMD_LIST && optind != argc - 1) ||
(cc.cmd == CMD_LIST && optind != argc))
usage();
if (cc.cmd != CMD_LIST) {
if (strlcpy(cc.logname, argv[optind], sizeof(cc.logname)) >=
sizeof(cc.logname))
errx(1, "Specified log name is too long");
}
memset(&ctl, '\0', sizeof(ctl));
strlcpy(ctl.sun_path, ctlsock_path, sizeof(ctl.sun_path));
ctl.sun_family = AF_UNIX;
if ((ctlsock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
err(1, "socket");
if (connect(ctlsock, (struct sockaddr *)&ctl, sizeof(ctl)) == -1)
err(1, "connect: %s", ctl.sun_path);
if ((ctlf = fdopen(ctlsock, "r+")) == NULL)
err(1, "fdopen");
if (pledge("stdio", NULL) == -1)
err(1, "stdio");
cc.version = htonl(CTL_VERSION);
cc.cmd = htonl(cc.cmd);
/* Send command */
if (fwrite(&cc, sizeof(cc), 1, ctlf) != 1)
err(1, "fwrite");
fflush(ctlf);
setvbuf(ctlf, NULL, _IOLBF, 0);
setvbuf(stdout, NULL, _IOLBF, 0);
/* Fetch header */
if (fread(&rr, sizeof(rr), 1, ctlf) != 1)
err(1, "fread header");
if (ntohl(rr.version) != CTL_VERSION)
errx(1, "unsupported syslogd version");
/* Write out reply */
while ((fgets(buf, sizeof(buf), ctlf)) != NULL) {
if (!strcmp(buf, "<ENOBUFS>\n"))
fprintf(stderr, "syslogc [%s]: Lines were dropped!\n",
cc.logname);
else
fputs(buf, stdout);
}
if (oflag && (ntohl(rr.flags) & CTL_HDR_FLAG_OVERFLOW)) {
printf("%s has overflowed\n", cc.logname);
rval = 1;
}
fclose(ctlf);
close(ctlsock);
exit(rval);
}
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