system_cmds-880.100.5.tar.gz

[apple/system_cmds.git] / dmesg.tproj / dmesg.c

diff --git a/dmesg.tproj/dmesg.c b/dmesg.tproj/dmesg.c
index 10d5caeea1a180b6ea732c800d40bd1bd6357ccc..ed62442ebc5b6a0fcb77c12486c9db39c2a073f3 100644 (file)
--- a/dmesg.tproj/dmesg.c
+++ b/dmesg.tproj/dmesg.c
@@ -1,8 +1,8 @@
 /*
- * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 1999-2016 Apple Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
- * 
+ *
  * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
  * Reserved.  This file contains Original Code and/or Modifications of
  * Original Code as defined in and that are subject to the Apple Public
@@ -10,7 +10,7 @@
  * except in compliance with the License.  Please obtain a copy of the
  * License at http://www.apple.com/publicsource and read it before using
  * this file.
- * 
+ *
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
@@ -18,7 +18,7 @@
  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  * License for the specific language governing rights and limitations
  * under the License."
- * 
+ *
  * @APPLE_LICENSE_HEADER_END@
  */
 /*-
@@ -54,117 +54,48 @@
  * SUCH DAMAGE.
  */
 
-#include <sys/cdefs.h>
-#include <sys/msgbuf.h>
-
-#include <fcntl.h>
-#include <kvm.h>
-#include <limits.h>
-#include <nlist.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <time.h>
-#include <unistd.h>
 #include <vis.h>
+#include <sys/sysctl.h>
+#include <libproc.h>
 
-struct nlist nl[] = {
-#define        X_MSGBUF        0
-       { "_msgbufp" },
-       { NULL },
-};
-
-void usage __P((void));
-
-#define        KREAD(addr, var) \
-       kvm_read(kd, addr, &var, sizeof(var)) != sizeof(var)
+static void
+usage(void)
+{
+       (void)fprintf(stderr, "usage: sudo dmesg\n");
+       exit(1);
+}
 
 int
-main(argc, argv)
-       int argc;
-       char *argv[];
+main(int argc, char **argv)
 {
-       register int ch, newl, skip;
-       register char *p, *ep;
-       struct msgbuf *bufp, cur;
-       char *memf, *nlistf;
-       kvm_t *kd;
-       char buf[5];
+       char *msgbuf, *visbuf;
+       int msgbufsize;
+       size_t sysctlsize = sizeof(msgbufsize);
+       long data_size;
 
-       memf = nlistf = NULL;
-       while ((ch = getopt(argc, argv, "M:N:")) != EOF)
-               switch(ch) {
-               case 'M':
-                       memf = optarg;
-                       break;
-               case 'N':
-                       nlistf = optarg;
-                       break;
-               case '?':
-               default:
-                       usage();
-               }
-       argc -= optind;
-       argv += optind;
+       if (argc > 1)
+               usage();
 
-       /*
-        * Discard setgid privileges if not the running kernel so that bad
-        * guys can't print interesting stuff from kernel memory.
-        */
-       if (memf != NULL || nlistf != NULL)
-               setgid(getgid());
+       if (sysctlbyname("kern.msgbuf", &msgbufsize, &sysctlsize, NULL, 0)) {
+               perror("Unable to size kernel buffer");
+       }
 
-       /* Read in kernel message buffer, do sanity checks. */
-       if ((kd = kvm_open(nlistf, memf, NULL, O_RDONLY, "dmesg")) == NULL)
-               exit (1);
-       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) || KREAD((long)bufp, cur))
-               errx(1, "kvm_read: %s", kvm_geterr(kd));
-       kvm_close(kd);
-       if (cur.msg_magic != MSG_MAGIC)
-               errx(1, "magic number incorrect");
-       if (cur.msg_bufx >= MSG_BSIZE)
-               cur.msg_bufx = 0;
+       msgbuf = malloc(msgbufsize);
+       if (msgbuf == NULL) {
+               perror("Unable to allocate a message buffer");
+       }
 
-       /*
-        * The message buffer is circular; start at the read pointer, and
-        * go to the write pointer - 1.
-        */
-       p = cur.msg_bufc + cur.msg_bufx;
-       ep = cur.msg_bufc + cur.msg_bufx - 1;
-       for (newl = skip = 0; p != ep; ++p) {
-               if (p == cur.msg_bufc + MSG_BSIZE)
-                       p = cur.msg_bufc;
-               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';
-               (void)vis(buf, ch, 0, 0);
-               if (buf[1] == 0)
-                       (void)putchar(buf[0]);
-               else
-                       (void)printf("%s", buf);
+       if ((data_size = proc_kmsgbuf(msgbuf, msgbufsize)) == 0){
+               perror("Unable to obtain kernel buffer");
+               usage();
        }
-       if (!newl)
-               (void)putchar('\n');
-       exit(0);
-}
 
-void
-usage()
-{
-       (void)fprintf(stderr, "usage: dmesg [-M core] [-N system]\n");
-       exit(1);
+       visbuf = malloc(data_size*4);
+       strvis(visbuf, msgbuf, 0);
+       printf("%s", visbuf);
+       free(visbuf);
+       free(msgbuf);
+       exit(0);
 }