/* $OpenBSD: dmesg.c,v 1.28 2017/08/26 08:53:20 tom Exp $ */ /* $NetBSD: dmesg.c,v 1.8 1995/03/18 14:54:49 cgd Exp $ */ /*- * Copyright (c) 1991, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef NOKVM struct nlist nl[] = { #define X_MSGBUF 0 { "_msgbufp" }, { NULL }, }; #endif void usage(void); #define KREAD(addr, var) \ kvm_read(kd, addr, &var, sizeof(var)) != sizeof(var) int main(int argc, char *argv[]) { int ch, newl, skip, i; char *p; struct msgbuf cur; char *memf, *nlistf, *bufdata = NULL; int startupmsgs = 0; char buf[5]; memf = nlistf = NULL; while ((ch = getopt(argc, argv, "sM:N:")) != -1) switch(ch) { case 's': startupmsgs = 1; break; case 'M': memf = optarg; break; case 'N': nlistf = optarg; break; case '?': default: usage(); } argc -= optind; argv += optind; if (memf == NULL && nlistf == NULL) { int mib[2], msgbufsize; size_t len; mib[0] = CTL_KERN; mib[1] = startupmsgs ? KERN_CONSBUFSIZE : KERN_MSGBUFSIZE; len = sizeof(msgbufsize); if (sysctl(mib, 2, &msgbufsize, &len, NULL, 0)) err(1, "sysctl: %s", startupmsgs ? "KERN_CONSBUFSIZE" : "KERN_MSGBUFSIZE"); msgbufsize += sizeof(struct msgbuf) - 1; bufdata = calloc(1, msgbufsize); if (bufdata == NULL) errx(1, "couldn't allocate space for buffer data"); mib[1] = startupmsgs ? KERN_CONSBUF : KERN_MSGBUF; len = msgbufsize; if (sysctl(mib, 2, bufdata, &len, NULL, 0)) err(1, "sysctl: %s", startupmsgs ? "KERN_CONSBUF" : "KERN_MSGBUF"); if (pledge("stdio", NULL) == -1) err(1, "pledge"); memcpy(&cur, bufdata, sizeof(cur)); bufdata = ((struct msgbuf *)bufdata)->msg_bufc; } else { #ifndef NOKVM struct msgbuf *bufp; kvm_t *kd; /* Read in kernel message buffer, do sanity checks. */ if ((kd = kvm_open(nlistf, memf, NULL, O_RDONLY, "dmesg")) == NULL) return (1); if (pledge("stdio", NULL) == -1) err(1, "pledge"); if (kvm_nlist(kd, nl) == -1) errx(1, "kvm_nlist: %s", kvm_geterr(kd)); if (nl[X_MSGBUF].n_type == 0) errx(1, "%s: msgbufp not found", nlistf ? nlistf : "namelist"); if (KREAD(nl[X_MSGBUF].n_value, bufp)) errx(1, "kvm_read: %s: (0x%lx)", kvm_geterr(kd), nl[X_MSGBUF].n_value); if (KREAD((long)bufp, cur)) errx(1, "kvm_read: %s (%0lx)", kvm_geterr(kd), (unsigned long)bufp); if (cur.msg_magic != MSG_MAGIC) errx(1, "magic number incorrect"); bufdata = malloc(cur.msg_bufs); if (bufdata == NULL) errx(1, "couldn't allocate space for buffer data"); if (kvm_read(kd, (long)&bufp->msg_bufc, bufdata, cur.msg_bufs) != cur.msg_bufs) errx(1, "kvm_read: %s", kvm_geterr(kd)); kvm_close(kd); #endif } if (cur.msg_bufx >= cur.msg_bufs) cur.msg_bufx = 0; /* * The message buffer is circular; start at the read pointer, and * go to the write pointer - 1. */ for (newl = skip = i = 0, p = bufdata + cur.msg_bufx; i < cur.msg_bufs; i++, p++) { if (p == bufdata + cur.msg_bufs) p = bufdata; ch = *p; /* Skip "\n<.*>" syslog sequences. */ if (skip) { if (ch == '>') newl = skip = 0; continue; } if (newl && ch == '<') { skip = 1; continue; } if (ch == '\0') continue; newl = ch == '\n'; vis(buf, ch, 0, 0); if (buf[1] == 0) putchar(buf[0]); else printf("%s", buf); } if (!newl) putchar('\n'); return (0); } void usage(void) { extern char *__progname; fprintf(stderr, "usage: %s [-s] [-M core] [-N system]\n", __progname); exit(1); }