audit for proper error handling, apply a few size optimizations

 -Erik

diff --git a/util-linux/dmesg.c b/util-linux/dmesg.c
index 73de6d1ae9ba84bf65f72f34b1f713b97fd208be..56e0771f0facb4fd111ab799701b3e75b5d7473a 100644 (file)
--- a/util-linux/dmesg.c
+++ b/util-linux/dmesg.c
@@ -13,11 +13,15 @@
  * from util-linux -- adapted for busybox by 
  * Erik Andersen <andersee@debian.org>. I ripped out Native Language 
  * Support, replaced getopt, added some gotos for redundant stuff.
+ *
+ * Audited and cleaned up on 7 March 2003 to reduce size of
+ * check error handling by Erik Andersen <andersee@debian.org>
  */
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <getopt.h>
+#include <errno.h>
 
 #if __GNU_LIBRARY__ < 5
 # ifdef __alpha__
@@ -32,34 +36,31 @@
 int dmesg_main(int argc, char **argv)
 {
        char *buf;
-       int c;
        int bufsize = 8196;
-       int i;
-       int n;
+       int i, n;
        int level = 0;
        int lastc;
        int cmd = 3;
 
-       while ((c = getopt(argc, argv, "cn:s:")) != EOF) {
-               switch (c) {
-               case 'c':
-                       cmd = 4;
-                       break;
-               case 'n':
-                       cmd = 8;
-                       if (optarg == NULL)
-                               show_usage();
-                       level = atoi(optarg);
-                       break;
-               case 's':
-                       if (optarg == NULL)
+       while ((i = getopt(argc, argv, "cn:s:")) != EOF) {
+               switch (i) {
+                       case 'c':
+                               cmd = 4;
+                               break;
+                       case 'n':
+                               cmd = 8;
+                               level = bb_xgetlarg(optarg, 10, 0, 10);
+                               break;
+                       case 's':
+                               /* I think a 512k max kernel ring buffer is big enough for
+                                * anybody, as the default is 16k...  Could be wrong though.
+                                * If so I'm sure I'll hear about it by the enraged masses*/
+                               bufsize = bb_xgetlarg(optarg, 10, 4096, 512*1024);
+                               break;
+                       default:
                                show_usage();
-                       bufsize = atoi(optarg);
-                       break;
-               default:
-                       show_usage();
                }
-       }                       
+       }
 
        if (optind < argc) {
                show_usage();
@@ -67,15 +68,13 @@ int dmesg_main(int argc, char **argv)
 
        if (cmd == 8) {
                if (klogctl(cmd, NULL, level) < 0)
-                       perror_msg_and_die("klogctl");
-               return EXIT_SUCCESS;
+                       goto die_the_death;
+               goto all_done;
        }
 
-       if (bufsize < 4096)
-               bufsize = 4096;
-       buf = (char *) xmalloc(bufsize);
+       buf = xmalloc(bufsize);
        if ((n = klogctl(cmd, buf, bufsize)) < 0)
-               perror_msg_and_die("klogctl");
+               goto die_the_death;
 
        lastc = '\n';
        for (i = 0; i < n; i++) {
@@ -91,5 +90,13 @@ int dmesg_main(int argc, char **argv)
        }
        if (lastc != '\n')
                putchar('\n');
+all_done:
+#ifdef CONFIG_FEATURE_CLEAN_UP
+       if (buf) {
+               free(buf);
+       }
+#endif
        return EXIT_SUCCESS;
+die_the_death:
+       perror_msg_and_die("klogctl");
 }