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path: root/fwd_rule.c
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Diffstat (limited to 'fwd_rule.c')
-rw-r--r--fwd_rule.c116
1 files changed, 104 insertions, 12 deletions
diff --git a/fwd_rule.c b/fwd_rule.c
index 200f4b5..5fc04d7 100644
--- a/fwd_rule.c
+++ b/fwd_rule.c
@@ -181,6 +181,89 @@ static bool fwd_rule_conflicts(const struct fwd_rule *a, const struct fwd_rule *
}
/**
+ * fwd_rule_match() - Test if two rules exactly match each other
+ * @a: Rule to check against @b
+ * @b: Rule to check against @a
+ *
+ * Return: true if rules match exactly, false otherwise
+ */
+static bool fwd_rule_match(const struct fwd_rule *a, const struct fwd_rule *b)
+{
+ return !memcmp(a, b, sizeof(*a));
+}
+
+/**
+ * fwd_rule_clear() - Clear a forwarding table
+ * @fwd: Table to clear (might be NULL)
+ */
+void fwd_rule_clear(struct fwd_table *fwd)
+{
+ if (!fwd)
+ return;
+
+ /* TODO: check that there are no open sockets in the table before
+ * going on. See also a related item in fwd_rule_del().
+ */
+
+ fwd->count = 0;
+ fwd->sock_count = 0;
+}
+
+/**
+ * fwd_rule_del() - Partially validate and delete a rule from a forwarding table
+ * @fwd: Table to delete from
+ * @rule: Rule to delete (must conflict with an existing rule)
+ *
+ * Return: 0 on success, negative error code on failure (-ENOENT if not found)
+ *
+ * NOTE: This function can't be used for a forwarding table with any open socket
+ * stored in fwd->rulesocks.
+ */
+static int fwd_rule_del(struct fwd_table *fwd, const struct fwd_rule *rule)
+{
+ char rulestr[FWD_RULE_STRLEN], oldstr[FWD_RULE_STRLEN];
+ unsigned num, i;
+
+ for (i = 0; i < fwd->count; i++) {
+ if (fwd_rule_match(rule, &fwd->rules[i]))
+ break;
+
+ if (fwd_rule_conflicts(rule, &fwd->rules[i])) {
+ warn(
+"Specifier %s conflicts with rule %s, but doesn't match it, can't delete",
+ fwd_rule_fmt(rule, rulestr, sizeof(rulestr)),
+ fwd_rule_fmt(&fwd->rules[i], oldstr, sizeof(oldstr)));
+ return -EINVAL;
+ }
+ }
+
+ if (i == fwd->count) {
+ warn("Couldn't find forwarding rule to delete: %s",
+ fwd_rule_fmt(rule, rulestr, sizeof(rulestr)));
+ return -ENOENT;
+ }
+
+ /* Don't use anything else from 'rule' as passed, it's not validated */
+ rule = &fwd->rules[i];
+ num = (unsigned)rule->last - rule->first + 1;
+
+ fwd->count--;
+
+ memmove((void *)(fwd->rulesocks + i), (void *)(fwd->rulesocks + i + 1),
+ (fwd->count - i) * sizeof(*fwd->rulesocks));
+
+ /* TODO: move sockets stored starting from fwd->rulesocks[i + 1], should
+ * we ever need to delete rules from a table with open sockets.
+ */
+ fwd->sock_count -= num;
+
+ memmove(fwd->rules + i, fwd->rules + i + 1,
+ (fwd->count - i) * sizeof(*fwd->rules));
+
+ return 0;
+}
+
+/**
* fwd_rule_add() - Validate and add a rule to a forwarding table
* @fwd: Table to add to
* @new: Rule to add
@@ -370,6 +453,7 @@ static int parse_keyword(const char *s, const char **endptr, const char *kw)
* fwd_rule_range_except() - Set up forwarding for a range of ports minus a
* bitmap of exclusions
* @fwd: Forwarding table to be updated
+ * @del: Delete resulting rules from forwarding table, instead of adding
* @proto: Protocol to forward
* @addr: Listening address
* @ifname: Listening interface
@@ -379,8 +463,8 @@ static int parse_keyword(const char *s, const char **endptr, const char *kw)
* @to: Port to translate @first to when forwarding
* @flags: Flags for forwarding entries
*/
-static void fwd_rule_range_except(struct fwd_table *fwd, uint8_t proto,
- const union inany_addr *addr,
+static void fwd_rule_range_except(struct fwd_table *fwd, bool del,
+ uint8_t proto, const union inany_addr *addr,
const char *ifname,
uint16_t first, uint16_t last,
const uint8_t *exclude, uint16_t to,
@@ -420,15 +504,20 @@ static void fwd_rule_range_except(struct fwd_table *fwd, uint8_t proto,
rule.last = i - 1;
rule.to = base + delta;
- if (fwd_rule_add(fwd, &rule) < 0)
- goto fail;
+ if (del) {
+ if (fwd_rule_del(fwd, &rule) < 0)
+ goto fail;
+ } else {
+ if (fwd_rule_add(fwd, &rule) < 0)
+ goto fail;
+ }
base = i - 1;
}
return;
fail:
- die("Unable to add rule %s",
+ die("Unable to %s rule %s", del ? "delete" : "add",
fwd_rule_fmt(&rule, rulestr, sizeof(rulestr)));
}
@@ -447,12 +536,13 @@ fail:
/**
* fwd_rule_parse_ports() - Parse port range(s) specifier
* @fwd: Forwarding table to be updated
+ * @del: Delete resulting rules from forwarding table, instead of adding
* @proto: Protocol to forward
* @addr: Listening address for forwarding
* @ifname: Interface name for listening
* @spec: Port range(s) specifier
*/
-static void fwd_rule_parse_ports(struct fwd_table *fwd, uint8_t proto,
+static void fwd_rule_parse_ports(struct fwd_table *fwd, bool del, uint8_t proto,
const union inany_addr *addr,
const char *ifname,
const char *spec)
@@ -509,7 +599,7 @@ static void fwd_rule_parse_ports(struct fwd_table *fwd, uint8_t proto,
/* Exclude ephemeral ports */
fwd_port_map_ephemeral(exclude);
- fwd_rule_range_except(fwd, proto, addr, ifname,
+ fwd_rule_range_except(fwd, del, proto, addr, ifname,
1, NUM_PORTS - 1, exclude,
1, flags | FWD_WEAK);
return;
@@ -539,7 +629,7 @@ static void fwd_rule_parse_ports(struct fwd_table *fwd, uint8_t proto,
if (p != ep) /* Garbage after the ranges */
goto bad;
- fwd_rule_range_except(fwd, proto, addr, ifname,
+ fwd_rule_range_except(fwd, del, proto, addr, ifname,
orig_range.first, orig_range.last,
exclude,
mapped_range.first, flags);
@@ -553,10 +643,12 @@ bad:
/**
* fwd_rule_parse() - Parse port configuration option
* @optname: Short option name, t, T, u, or U
+ * @del: Delete resulting rules from forwarding table, instead of adding
* @optarg: Option argument (port specification)
* @fwd: Forwarding table to be updated
*/
-void fwd_rule_parse(char optname, const char *optarg, struct fwd_table *fwd)
+void fwd_rule_parse(char optname, bool del, const char *optarg,
+ struct fwd_table *fwd)
{
union inany_addr addr_buf = inany_any6, *addr = &addr_buf;
char buf[BUFSIZ], *spec, *ifname = NULL;
@@ -634,12 +726,12 @@ void fwd_rule_parse(char optname, const char *optarg, struct fwd_table *fwd)
optname, optarg);
if (fwd->caps & FWD_CAP_IPV4) {
- fwd_rule_parse_ports(fwd, proto,
+ fwd_rule_parse_ports(fwd, del, proto,
&inany_loopback4, NULL,
spec);
}
if (fwd->caps & FWD_CAP_IPV6) {
- fwd_rule_parse_ports(fwd, proto,
+ fwd_rule_parse_ports(fwd, del, proto,
&inany_loopback6, NULL,
spec);
}
@@ -655,7 +747,7 @@ void fwd_rule_parse(char optname, const char *optarg, struct fwd_table *fwd)
optname, optarg);
}
- fwd_rule_parse_ports(fwd, proto, addr, ifname, spec);
+ fwd_rule_parse_ports(fwd, del, proto, addr, ifname, spec);
}
/**
generated by cgit v1.2.3 (git 2.25.1) at 2026-05-07 16:30:17 +0000