add negative rule counter support

diff --git a/ebtables.c b/ebtables.c
index f33d270..21a9a47 100644 (file)
--- a/ebtables.c
+++ b/ebtables.c
@@ -1081,7 +1081,7 @@ static int check_rule_exists(int rule_nr)
        /*
         * handle '-D chain rulenr' command
         */
-       if (rule_nr != -1) {
+       if (rule_nr != 0) {
                if (rule_nr > entries->nentries)
                        return -1;
                /*
@@ -1186,12 +1186,12 @@ static void add_rule(int rule_nr)
        struct ebt_u_watcher_list *w_l;
        struct ebt_u_entries *entries = to_chain(), *entries2;
 
-       if (rule_nr != -1) { /* command -I */
-               if (--rule_nr > entries->nentries)
-                       print_error("rule nr too high: %d > %d", rule_nr + 1,
-                          entries->nentries + 1);
-       } else
-               rule_nr = entries->nentries;
+       if (rule_nr <= 0)
+               rule_nr += entries->nentries;
+       else
+               rule_nr--;
+       if (rule_nr > entries->nentries || rule_nr < 0)
+               print_error("The specified rule number is incorrect");
        /*
         * we're adding one rule
         */
@@ -1282,6 +1282,16 @@ static void delete_rule(int begin, int end)
        struct ebt_u_entry **u_e, *u_e2;
        struct ebt_u_entries *entries = to_chain(), *entries2;
 
+       if (begin < 0) {
+               if (begin < entries->nentries)
+                       goto rule_error;
+               begin += entries->nentries + 1;
+       }
+       if (end < 0)
+               end += entries->nentries + 1;
+       if (begin > end)
+rule_error:
+               print_error("Sorry, wrong rule numbers");
        if ((begin = check_rule_exists(begin)) == -1 ||
            (end = check_rule_exists(end)) == -1)
                print_error("Sorry, rule does not exist");
@@ -1535,24 +1545,22 @@ static int parse_delete_rule(const char *argv, int *rule_nr, int *rule_nr_end)
        if (colon) {
                *colon = '\0';
                if (*(colon + 1) == '\0')
-                       *rule_nr_end = -1;
+                       *rule_nr_end = -1; /* until the last rule */
                else {
                        *rule_nr_end = strtol(colon + 1, &buffer, 10);
-                       if (*buffer != '\0' || *rule_nr_end < 0)
+                       if (*buffer != '\0' || *rule_nr_end == 0)
                                return -1;
                }
        }
        if (colon == argv)
-               *rule_nr = 1;
+               *rule_nr = 1; /* beginning with the first rule */
        else {
                *rule_nr = strtol(argv, &buffer, 10);
-               if (*buffer != '\0' || *rule_nr < 0)
+               if (*buffer != '\0' || *rule_nr == 0)
                        return -1;
        }
        if (!colon)
                *rule_nr_end = *rule_nr;
-       if (*rule_nr_end != -1 && *rule_nr > *rule_nr_end)
-               return -1;
        return 0;
 }
 
@@ -1620,8 +1628,8 @@ int main(int argc, char *argv[])
         */
        int zerochain = -1;
        int policy = 0;
-       int rule_nr = -1; /* used for -[D,I] */
-       int rule_nr_end = -1; /* used for -I */
+       int rule_nr = 0; /* used for -[D,I] */
+       int rule_nr_end = 0; /* used for -I */
        struct ebt_u_target *t;
        struct ebt_u_match *m;
        struct ebt_u_watcher *w;
@@ -1758,7 +1766,8 @@ int main(int argc, char *argv[])
                        }
 
                        if (c == 'D' && optind < argc &&
-                           argv[optind][0] != '-') {
+                           (argv[optind][0] != '-' ||
+                           (argv[optind][1] >= '0' && argv[optind][1] <= '9'))) {
                                if (parse_delete_rule(argv[optind],
                                    &rule_nr, &rule_nr_end))
                                        print_error("Problem with the "
@@ -1766,11 +1775,12 @@ int main(int argc, char *argv[])
                                optind++;
                        }
                        if (c == 'I') {
-                               if (optind >= argc || argv[optind][0] == '-')
+                               if (optind >= argc || (argv[optind][0] == '-' &&
+                                   (argv[optind][1] < '0' || argv[optind][1] > '9')))
                                        print_error("No rulenr for -I"
                                                    " specified");
                                rule_nr = strtol(argv[optind], &buffer, 10);
-                               if (*buffer != '\0' || rule_nr < 0)
+                               if (*buffer != '\0')
                                        print_error("Problem with the "
                                                    "specified rule number");
                                optind++;
@@ -2320,11 +2330,8 @@ check_extension:
                                e = e->next;
                        }
                }
-       } else if (replace.command == 'D') {
-               if (rule_nr != -1 && rule_nr_end == -1)
-                       rule_nr_end = entries->nentries;
+       } else if (replace.command == 'D')
                delete_rule(rule_nr, rule_nr_end);
-       }
        /*
         * commands -N, -E, -X, --atomic-commit, --atomic-commit, --atomic-save,
         * --init-table fall through