1 files changed, 42 insertions, 22 deletions

diff --git a/procps/sysctl.c b/procps/sysctl.c
index b17f5e896..827e09cce 100644
--- a/procps/sysctl.c
+++ b/procps/sysctl.c
@@ -16,22 +16,22 @@
 //config:       help
 //config:       Configure kernel parameters at runtime.
 
-//applet:IF_BB_SYSCTL(APPLET(sysctl, BB_DIR_SBIN, BB_SUID_DROP))
+//applet:IF_BB_SYSCTL(APPLET_NOEXEC(sysctl, sysctl, BB_DIR_SBIN, BB_SUID_DROP, sysctl))
 
 //kbuild:lib-$(CONFIG_BB_SYSCTL) += sysctl.o
 
 //usage:#define sysctl_trivial_usage
-//usage:       "[OPTIONS] [KEY[=VALUE]]..."
+//usage:       "-p [-enq] [FILE...] / [-enqaw] [KEY[=VALUE]]..."
 //usage:#define sysctl_full_usage "\n\n"
 //usage:       "Show/set kernel parameters\n"
+//usage:     "\n        -p      Set values from FILEs (default /etc/sysctl.conf)"
 //usage:     "\n        -e      Don't warn about unknown keys"
 //usage:     "\n        -n      Don't show key names"
+//usage:     "\n        -q      Quiet"
 //usage:     "\n        -a      Show all values"
 /* Same as -a, no need to show it */
 /* //usage:     "\n     -A      Show all values in table form" */
 //usage:     "\n        -w      Set values"
-//usage:     "\n        -p FILE Set values from FILE (default /etc/sysctl.conf)"
-//usage:     "\n        -q      Set values silently"
 //usage:
 //usage:#define sysctl_example_usage
 //usage:       "sysctl [-n] [-e] variable...\n"
@@ -48,7 +48,7 @@ enum {
         FLAG_TABLE_FORMAT    = 1 << 2, /* not implemented */
         FLAG_SHOW_ALL        = 1 << 3,
         FLAG_PRELOAD_FILE    = 1 << 4,
-/* TODO: procps 3.2.8 seems to not require -w for KEY=VAL to work: */
+        /* NB: procps 3.2.8 does not require -w for KEY=VAL to work, it only rejects non-KEY=VAL form */
         FLAG_WRITE           = 1 << 5,
         FLAG_QUIET           = 1 << 6,
 };
@@ -104,6 +104,7 @@ static int sysctl_act_on_setting(char *setting)
         int fd, retval = EXIT_SUCCESS;
         char *cptr, *outname;
         char *value = value; /* for compiler */
+        bool writing = (option_mask32 & FLAG_WRITE);
 
         outname = xstrdup(setting);
 
@@ -114,8 +115,10 @@ static int sysctl_act_on_setting(char *setting)
                 cptr++;
         }
 
-        if (option_mask32 & FLAG_WRITE) {
-                cptr = strchr(setting, '=');
+        cptr = strchr(setting, '=');
+        if (cptr)
+                writing = 1;
+        if (writing) {
                 if (cptr == NULL) {
                         bb_error_msg("error: '%s' must be of the form name=value",
                                 outname);
@@ -147,7 +150,7 @@ static int sysctl_act_on_setting(char *setting)
                         break;
                 default:
                         bb_perror_msg("error %sing key '%s'",
-                                        option_mask32 & FLAG_WRITE ?
+                                        writing ?
                                                 "sett" : "read",
                                         outname);
                         break;
@@ -156,7 +159,7 @@ static int sysctl_act_on_setting(char *setting)
                 goto end;
         }
 
-        if (option_mask32 & FLAG_WRITE) {
+        if (writing) {
 //TODO: procps 3.2.7 writes "value\n", note trailing "\n"
                 xwrite_str(fd, value);
                 close(fd);
@@ -238,23 +241,33 @@ static int sysctl_handle_preload_file(const char *filename)
 {
         char *token[2];
         parser_t *parser;
+        int parse_flags;
 
         parser = config_open(filename);
         /* Must do it _after_ config_open(): */
         xchdir("/proc/sys");
-        /* xchroot("/proc/sys") - if you are paranoid */
 
-//TODO: ';' is comment char too
-//TODO: comment may be only at line start. "var=1 #abc" - "1 #abc" is the value
-// (but _whitespace_ from ends should be trimmed first (and we do it right))
-//TODO: "var==1" is mishandled (must use "=1" as a value, but uses "1")
-// can it be fixed by removing PARSE_COLLAPSE bit?
-        while (config_read(parser, token, 2, 2, "# \t=", PARSE_NORMAL)) {
+        parse_flags = 0;
+        parse_flags &= ~PARSE_COLLAPSE;   // NO (var==val is not var=val) - treat consecutive delimiters as one
+        parse_flags &= ~PARSE_TRIM;       // NO - trim leading and trailing delimiters
+        parse_flags |= PARSE_GREEDY;      // YES - last token takes entire remainder of the line
+        parse_flags &= ~PARSE_MIN_DIE;    // NO - die if < min tokens found
+        parse_flags &= ~PARSE_EOL_COMMENTS; // NO (only first char) - comments are recognized even if not first char
+        parse_flags |= PARSE_ALT_COMMENTS;// YES - two comment chars: ';' and '#'
+        /* <space><tab><space>#comment is also comment, not strictly 1st char only */
+        parse_flags |= PARSE_WS_COMMENTS; // YES - comments are recognized even if there is whitespace before
+        while (config_read(parser, token, 2, 2, ";#=", parse_flags)) {
                 char *tp;
+
+                trim(token[1]);
+                tp = trim(token[0]);
                 sysctl_dots_to_slashes(token[0]);
-                tp = xasprintf("%s=%s", token[0], token[1]);
-                sysctl_act_recursive(tp);
-                free(tp);
+                /* ^^^converted in-place. tp still points to NUL */
+                /* now, add "=TOKEN1" */
+                *tp++ = '=';
+                overlapping_strcpy(tp, token[1]);
+
+                sysctl_act_on_setting(token[0]);
         }
         if (ENABLE_FEATURE_CLEAN_UP)
                 config_close(parser);
@@ -273,12 +286,19 @@ int sysctl_main(int argc UNUSED_PARAM, char **argv)
         option_mask32 = opt;
 
         if (opt & FLAG_PRELOAD_FILE) {
+                int cur_dir_fd;
                 option_mask32 |= FLAG_WRITE;
-                /* xchdir("/proc/sys") is inside */
-                return sysctl_handle_preload_file(*argv ? *argv : "/etc/sysctl.conf");
+                if (!*argv)
+                        *--argv = (char*)"/etc/sysctl.conf";
+                cur_dir_fd = xopen(".", O_RDONLY | O_DIRECTORY);
+                do {
+                        /* xchdir("/proc/sys") is inside */
+                        sysctl_handle_preload_file(*argv);
+                        xfchdir(cur_dir_fd); /* files can be relative, must restore cwd */
+                } while (*++argv);
+                return 0; /* procps-ng 3.3.10 does not flag parse errors */
         }
         xchdir("/proc/sys");
-        /* xchroot("/proc/sys") - if you are paranoid */
         if (opt & (FLAG_TABLE_FORMAT | FLAG_SHOW_ALL)) {
                 return sysctl_act_recursive(".");
         }