1 /* $OpenBSD: syslogc.c,v 1.18 2015/10/13 16:30:55 deraadt 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 <stdint.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 2 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 #define CMD_READ_CONT 6 /* Read out log continuously */ 48 u_int32_t cmd; 49 u_int32_t lines; 50 char logname[MAX_MEMBUF_NAME]; 51 }; 52 53 /* Reply */ 54 struct ctl_reply_hdr { 55 u_int32_t version; 56 #define CTL_HDR_FLAG_OVERFLOW 0x01 57 u_int32_t flags; 58 /* Reply text follows, up to MAX_MEMBUF long */ 59 }; 60 61 static void 62 usage(void) 63 { 64 extern char *__progname; 65 66 fprintf(stderr, 67 "usage: %s [-Ccfo] [-n lines] [-s reporting_socket] logname\n" 68 " %s -q\n", __progname, __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 int ctlsock, ch, oflag, rval; 79 FILE *ctlf; 80 extern char *optarg; 81 extern int optind; 82 struct ctl_cmd cc; 83 struct ctl_reply_hdr rr; 84 const char *errstr; 85 86 memset(&cc, '\0', sizeof(cc)); 87 88 ctlsock_path = DEFAULT_CTLSOCK; 89 rval = oflag = 0; 90 while ((ch = getopt(argc, argv, "Ccfhon:qs:")) != -1) { 91 switch (ch) { 92 case 'C': 93 cc.cmd = CMD_CLEAR; 94 break; 95 case 'c': 96 cc.cmd = CMD_READ_CLEAR; 97 break; 98 case 'h': 99 usage(); 100 break; 101 case 'f': 102 cc.cmd = CMD_READ_CONT; 103 break; 104 case 'n': 105 cc.lines = strtonum(optarg, 1, UINT32_MAX, &errstr); 106 if (errstr) 107 errx(1, "number of lines is %s: %s", 108 errstr, optarg); 109 break; 110 case 'o': 111 cc.cmd = CMD_FLAGS; 112 oflag = 1; 113 break; 114 case 'q': 115 cc.cmd = CMD_LIST; 116 break; 117 case 's': 118 ctlsock_path = optarg; 119 break; 120 default: 121 usage(); 122 break; 123 } 124 } 125 126 if (cc.cmd == 0) 127 cc.cmd = CMD_READ; 128 129 if ((cc.cmd != CMD_LIST && optind != argc - 1) || 130 (cc.cmd == CMD_LIST && optind != argc)) 131 usage(); 132 133 if (cc.cmd != CMD_LIST) { 134 if (strlcpy(cc.logname, argv[optind], sizeof(cc.logname)) >= 135 sizeof(cc.logname)) 136 errx(1, "Specified log name is too long"); 137 } 138 139 memset(&ctl, '\0', sizeof(ctl)); 140 strlcpy(ctl.sun_path, ctlsock_path, sizeof(ctl.sun_path)); 141 ctl.sun_family = AF_UNIX; 142 143 if ((ctlsock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 144 err(1, "socket"); 145 if (connect(ctlsock, (struct sockaddr *)&ctl, sizeof(ctl)) == -1) 146 err(1, "connect: %s", ctl.sun_path); 147 if ((ctlf = fdopen(ctlsock, "r+")) == NULL) 148 err(1, "fdopen"); 149 150 if (pledge("stdio", NULL) == -1) 151 err(1, "stdio"); 152 153 cc.version = htonl(CTL_VERSION); 154 cc.cmd = htonl(cc.cmd); 155 /* Send command */ 156 if (fwrite(&cc, sizeof(cc), 1, ctlf) != 1) 157 err(1, "fwrite"); 158 159 fflush(ctlf); 160 setvbuf(ctlf, NULL, _IOLBF, 0); 161 setvbuf(stdout, NULL, _IOLBF, 0); 162 163 /* Fetch header */ 164 if (fread(&rr, sizeof(rr), 1, ctlf) != 1) 165 err(1, "fread header"); 166 167 if (ntohl(rr.version) != CTL_VERSION) 168 errx(1, "unsupported syslogd version"); 169 170 /* Write out reply */ 171 while ((fgets(buf, sizeof(buf), ctlf)) != NULL) { 172 if (!strcmp(buf, "<ENOBUFS>\n")) 173 fprintf(stderr, "syslogc [%s]: Lines were dropped!\n", 174 cc.logname); 175 else 176 fputs(buf, stdout); 177 } 178 179 if (oflag && (ntohl(rr.flags) & CTL_HDR_FLAG_OVERFLOW)) { 180 printf("%s has overflowed\n", cc.logname); 181 rval = 1; 182 } 183 184 fclose(ctlf); 185 close(ctlsock); 186 187 exit(rval); 188 } 189