Improve printing of the cmdline

- Print control characters in octal
- Shorten using an ellipsis when necessary

diff --git a/bin/named/main.c b/bin/named/main.c
index e4afdc5a6ae575e2cb8c4328cdcff926c18243e8..dbe39772db4cdaab59a85b384acf7e5fca7d4bc2 100644 (file)
--- a/bin/named/main.c
+++ b/bin/named/main.c
@@ -110,7 +110,8 @@ LIBDNS_EXTERNAL_DATA extern unsigned int dns_zone_mkey_month;
 static bool    want_stats = false;
 static char            program_name[NAME_MAX] = "named";
 static char            absolute_conffile[PATH_MAX];
-static char            saved_command_line[512];
+static char            saved_command_line[8192] =  { 0 };
+static char            ellipsis[5] = { 0 };
 static char            version[512];
 static unsigned int    maxsocks = 0;
 static int             maxudp = 0;
@@ -335,44 +336,76 @@ usage(void) {
 static void
 save_command_line(int argc, char *argv[]) {
        int i;
-       char *src;
-       char *dst;
-       char *eob;
-       const char truncated[] = "...";
-       bool quoted = false;
-
-       dst = saved_command_line;
-       eob = saved_command_line + sizeof(saved_command_line);
+       char *dst = saved_command_line;
+       char *eob = saved_command_line + sizeof(saved_command_line) - 1;
+       char *rollback;
 
        for (i = 1; i < argc && dst < eob; i++) {
+               char *src = argv[i];
+               bool quoted = false;
+
+               rollback = dst;
                *dst++ = ' ';
 
-               src = argv[i];
                while (*src != '\0' && dst < eob) {
-                       /*
-                        * This won't perfectly produce a shell-independent
-                        * pastable command line in all circumstances, but
-                        * comes close, and for practical purposes will
-                        * nearly always be fine.
-                        */
-                       if (quoted || isalnum(*src & 0xff) ||
+                       if (isalnum(*src) ||
                            *src == '-' || *src == '_' ||
-                           *src == '.' || *src == '/') {
+                           *src == '.' || *src == '/')
+                       {
                                *dst++ = *src++;
-                               quoted = false;
-                       } else {
+                       } else if (isprint(*src)) {
+                               if (dst + 2 >= eob) {
+                                       goto add_ellipsis;
+                               }
                                *dst++ = '\\';
-                               quoted = true;
+                               *dst++ = *src++;
+                       } else {
+                               /*
+                                * Control character found in the input,
+                                * quote the whole arg and restart
+                                */
+                               if (!quoted) {
+                                       dst = rollback;
+                                       src = argv[i];
+
+                                       if (dst + 3 >= eob) {
+                                               goto add_ellipsis;
+                                       }
+
+                                       *dst++ = ' ';
+                                       *dst++ = '$';
+                                       *dst++ = '\'';
+
+                                       quoted = true;
+                                       continue;
+                               } else {
+                                       char tmp[5];
+                                       int c = snprintf(tmp, sizeof(tmp),
+                                                        "\\%03o", *src++);
+                                       if (dst + c >= eob) {
+                                               goto add_ellipsis;
+                                       }
+                                       memmove(dst, tmp, c);
+                                       dst += c;
+                               }
                        }
                }
-       }
+               if (quoted) {
+                       if (dst == eob) {
+                               goto add_ellipsis;
+                       }
+                       *dst++ = '\'';
+               }
 
-       INSIST(sizeof(saved_command_line) >= sizeof(truncated));
+       }
 
-       if (dst == eob)
-               strcpy(eob - sizeof(truncated), truncated);
-       else
-               *dst = '\0';
+       if (dst < eob) {
+               return;
+       }
+add_ellipsis:
+       dst = rollback;
+       *dst = '\0';
+       strlcpy(ellipsis, " ...", sizeof(ellipsis));
 }
 
 static int
@@ -1005,8 +1038,8 @@ setup(void) {
 
        isc_log_write(named_g_lctx, NAMED_LOGCATEGORY_GENERAL,
                      NAMED_LOGMODULE_MAIN, ISC_LOG_NOTICE,
-                     "running as: %s%s",
-                     program_name, saved_command_line);
+                     "running as: %s%s%s",
+                     program_name, saved_command_line, ellipsis);
 #ifdef __clang__
        isc_log_write(named_g_lctx, NAMED_LOGCATEGORY_GENERAL,
                      NAMED_LOGMODULE_MAIN, ISC_LOG_NOTICE,