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authorBart De Schuymer <bdschuym@pandora.be>2003-07-13 18:48:02 +0000
committerBart De Schuymer <bdschuym@pandora.be>2003-07-13 18:48:02 +0000
commitf2bbbc347dd4bee36ec361318abbe2afe9b91d9b (patch)
tree8f19aa0d0169c5e56b0f30071f1558bbd270f20b
parent916ea8da053107792671934ead116c5d35e464f6 (diff)
Add -X without specified chain: removes all non-referenced user-defined
chains
-rw-r--r--userspace/ebtables2/ebtables.c202
1 files changed, 173 insertions, 29 deletions
diff --git a/userspace/ebtables2/ebtables.c b/userspace/ebtables2/ebtables.c
index 93ec90f..b7ba6f2 100644
--- a/userspace/ebtables2/ebtables.c
+++ b/userspace/ebtables2/ebtables.c
@@ -103,7 +103,7 @@ static struct option ebt_original_options[] =
{ "modprobe" , required_argument, 0, 'M' },
{ "new-chain" , required_argument, 0, 'N' },
{ "rename-chain" , required_argument, 0, 'E' },
- { "delete-chain" , required_argument, 0, 'X' },
+ { "delete-chain" , optional_argument, 0, 'X' },
{ "atomic-init" , no_argument , 0, 7 },
{ "atomic-commit" , no_argument , 0, 8 },
{ "atomic-file" , required_argument, 0, 9 },
@@ -841,7 +841,7 @@ static void print_help()
"--policy -P chain target : change policy on chain to target\n"
"--new-chain -N chain : create a user defined chain\n"
"--rename-chain -E old new : rename a chain\n"
-"--delete-chain -X chain : delete a user defined chain\n"
+"--delete-chain -X [chain] : delete a user defined chain\n"
"--atomic-commit : update the kernel w/t table contained in <FILE>\n"
"--atomic-init : put the initial kernel table into <FILE>\n"
"--atomic-save : put the current kernel table into <FILE>\n"
@@ -1513,8 +1513,10 @@ static void do_final_checks(struct ebt_u_entry *e, struct ebt_u_entries *entries
/*
* used for the -X command
+ * type = 0 => update chain jumps
+ * type = 1 => check for reference
*/
-static void check_for_references(int chain_nr)
+static int iterate_entries(int chain_nr, int silent, int type)
{
int i = -1, j;
struct ebt_u_entries *entries;
@@ -1540,15 +1542,145 @@ static void check_for_references(int chain_nr)
continue;
}
chain_jmp = ((struct ebt_standard_target *)e->t)->verdict;
- if (chain_jmp == chain_nr)
+ switch (type) {
+ case 1:
+ if (chain_jmp == chain_nr) {
+ if (silent)
+ return 1;
print_error("Can't delete the chain, it's referenced "
"in chain %s, rule %d", entries->name, j);
+ }
+ break;
+ case 0:
/* adjust the chain jumps when necessary */
if (chain_jmp > chain_nr)
((struct ebt_standard_target *)e->t)->verdict--;
+ break;
+ } /* end switch */
e = e->next;
}
}
+ return 0;
+}
+
+static void decrease_chain_jumps(int chain_nr)
+{
+ iterate_entries(chain_nr, 1, 0);
+}
+
+static int check_for_references(int chain_nr, int silent)
+{
+ return iterate_entries(chain_nr, silent, 1);
+}
+
+static int *determine_referenced_chains(int *n)
+{
+ int *nrs, i = 0, j = 0;
+
+ *n = 0;
+ while (nr_to_chain(i + NF_BR_NUMHOOKS)) {
+ if (check_for_references(i, 1))
+ (*n)++;
+ i++;
+ }
+ if (*n == 0)
+ return NULL;
+ nrs = malloc(*n * sizeof(int));
+ i = 0;
+ while (nr_to_chain(i + NF_BR_NUMHOOKS)) {
+ if (check_for_references(i, 1)) {
+ nrs[j] = i;
+ j++;
+ }
+ i++;
+ }
+ return nrs;
+}
+
+static void remove_udc(int udc_nr)
+{
+ struct ebt_u_chain_list *cl, **cl2;
+ struct ebt_u_entries *entries;
+ struct ebt_u_entry *u_e, *tmp;
+
+ /* first free the rules */
+ entries = nr_to_chain(udc_nr + NF_BR_NUMHOOKS);
+ u_e = entries->entries;
+ while (u_e) {
+ free_u_entry(u_e);
+ tmp = u_e->next;
+ free(u_e);
+ u_e = tmp;
+ }
+
+ /* next, remove the chain */
+ cl2 = &(replace.udc);
+ while ((*cl2)->udc != entries)
+ cl2 = &((*cl2)->next);
+ cl = (*cl2);
+ (*cl2) = (*cl2)->next;
+ free(cl->udc);
+ free(cl);
+}
+
+/* Removes all udc that aren't referenced at the time of execution */
+static void delete_all_user_chains()
+{
+ struct ebt_u_chain_list *chain;
+ int *ref, nr_ref, chain_nr = 0, counter_offset, i;
+ struct ebt_u_entries *entries;
+
+ /* initialize counterchanges */
+ counters_nochange();
+
+ ref = determine_referenced_chains(&nr_ref);
+
+ chain = replace.udc;
+ counter_offset = 0;
+ /* skip the standard chains */
+ for (i = 0; i < NF_BR_NUMHOOKS; i++)
+ if ((entries = nr_to_chain(i)) != NULL)
+ counter_offset += entries->nentries;
+
+ /* first update chain jumps and counterchanges */
+ while (chain) {
+ int nentries;
+
+ nentries = chain->udc->nentries;
+ for (i = 0; i < nr_ref; i++)
+ if (ref[i] == chain_nr)
+ goto letscontinue;
+ decrease_chain_jumps(chain_nr);
+ for (i = counter_offset; i < counter_offset + nentries; i++)
+ replace.counterchanges[i] = CNT_DEL;
+ replace.nentries -= nentries;
+letscontinue:
+ counter_offset += nentries;
+ chain = chain->next;
+ chain_nr++;
+ }
+ chain = replace.udc;
+ chain_nr = -1;
+ /* next, remove the chains, update the counter offset of
+ * non-removed chains */
+ counter_offset = 0;
+ while (chain) {
+ int real_cn = 0;
+
+ chain_nr++;
+ for (i = 0; i < nr_ref; i++)
+ if (ref[i] == chain_nr)
+ break;
+ if (i != nr_ref) {
+ real_cn++;
+ chain->udc->counter_offset -= counter_offset;
+ chain = chain->next;
+ continue;
+ }
+ counter_offset += chain->udc->nentries;
+ chain = chain->next;
+ remove_udc(real_cn);
+ }
}
static int parse_delete_rule(const char *argv, int *rule_nr, int *rule_nr_end)
@@ -1680,7 +1812,7 @@ int main(int argc, char *argv[])
* getopt saves the day
*/
while ((c = getopt_long(argc, argv,
- "-A:D:I:N:E:X:L::Z::F::P:Vhi:o:j:p:s:d:t:M:", ebt_options, NULL)) != -1) {
+ "-A:D:I:N:E:X::L::Z::F::P:Vhi:o:j:p:s:d:t:M:", ebt_options, NULL)) != -1) {
switch (c) {
case 'A': /* add a rule */
@@ -1695,7 +1827,8 @@ int main(int argc, char *argv[])
print_error("Multiple commands not allowed");
replace.flags |= OPT_COMMAND;
get_kernel_table();
- if (optarg[0] == '-' || !strcmp(optarg, "!"))
+ if (optarg && (optarg[0] == '-' ||
+ !strcmp(optarg, "!")))
print_error("No chain name specified");
if (c == 'N') {
struct ebt_u_chain_list *cl, **cl2;
@@ -1735,6 +1868,40 @@ int main(int argc, char *argv[])
counters_nochange();
break;
}
+ if (c == 'X') {
+ char *opt;
+ int udc_nr;
+
+ if (!optarg && (optind >= argc ||
+ (argv[optind][0] != '-'
+ && strcmp(argv[optind], "!")))) {
+ delete_all_user_chains();
+ break;
+ }
+ if (optarg)
+ opt = optarg;
+ else {
+ opt = argv[optind];
+ optind++;
+ }
+ if ((replace.selected_hook = get_hooknr(opt)) == -1)
+ print_error("Chain %s doesn't exist", optarg);
+ if (replace.selected_hook < NF_BR_NUMHOOKS)
+ print_error("You can't remove a standard chain");
+ /*
+ * if the chain is referenced, don't delete it,
+ * also decrement jumps to a chain behind the
+ * one we're deleting
+ */
+ udc_nr=replace.selected_hook-NF_BR_NUMHOOKS;
+ check_for_references(udc_nr, 0);
+ decrease_chain_jumps(udc_nr);
+ if (flush_chains() == -1)
+ counters_nochange();
+ remove_udc(udc_nr);
+ break;
+ }
+
if ((replace.selected_hook = get_hooknr(optarg)) == -1)
print_error("Chain %s doesn't exist", optarg);
if (c == 'E') {
@@ -1756,29 +1923,6 @@ int main(int argc, char *argv[])
optind++;
break;
}
- if (c == 'X') {
- struct ebt_u_chain_list *cl, **cl2;
-
- if (replace.selected_hook < NF_BR_NUMHOOKS)
- print_error("You can't remove a standard chain");
- /*
- * if the chain is referenced, don't delete it,
- * also decrement jumps to a chain behind the
- * one we're deleting
- */
- check_for_references(replace.selected_hook - NF_BR_NUMHOOKS);
- if (flush_chains() == -1)
- counters_nochange();
- entries = to_chain();
- cl2 = &(replace.udc);
- while ((*cl2)->udc != entries)
- cl2 = &((*cl2)->next);
- cl = (*cl2);
- (*cl2) = (*cl2)->next;
- free(cl->udc);
- free(cl);
- break;
- }
if (c == 'D' && optind < argc &&
(argv[optind][0] != '-' ||