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-rw-r--r--src/shared/in-addr-prefix-util.c325
1 files changed, 325 insertions, 0 deletions
diff --git a/src/shared/in-addr-prefix-util.c b/src/shared/in-addr-prefix-util.c
new file mode 100644
index 0000000..7c0033d
--- /dev/null
+++ b/src/shared/in-addr-prefix-util.c
@@ -0,0 +1,325 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "alloc-util.h"
+#include "extract-word.h"
+#include "hostname-util.h"
+#include "in-addr-prefix-util.h"
+#include "string-util.h"
+
+/* 0.0.0.0/0 */
+#define IN_ADDR_PREFIX_IPV4_ANY ((struct in_addr_prefix) { .family = AF_INET })
+/* ::/0 */
+#define IN_ADDR_PREFIX_IPV6_ANY ((struct in_addr_prefix) { .family = AF_INET6 })
+/* 127.0.0.0/8 */
+#define IN_ADDR_PREFIX_IPV4_LOCALHOST \
+ ((struct in_addr_prefix) { \
+ .family = AF_INET, \
+ .address.in.s_addr = htobe32(UINT32_C(127) << 24), \
+ .prefixlen = 8, \
+ })
+/* ::1/128 */
+#define IN_ADDR_PREFIX_IPV6_LOCALHOST \
+ ((struct in_addr_prefix) { \
+ .family = AF_INET6, \
+ .address.in6 = IN6ADDR_LOOPBACK_INIT, \
+ .prefixlen = 128, \
+ })
+/* 169.254.0.0/16 */
+#define IN_ADDR_PREFIX_IPV4_LINKLOCAL \
+ ((struct in_addr_prefix) { \
+ .family = AF_INET, \
+ .address.in.s_addr = htobe32((UINT32_C(169) << 24) | \
+ (UINT32_C(254) << 16)), \
+ .prefixlen = 16, \
+ })
+/* fe80::/64 */
+#define IN_ADDR_PREFIX_IPV6_LINKLOCAL \
+ ((struct in_addr_prefix) { \
+ .family = AF_INET6, \
+ .address.in6.s6_addr[0] = 0xfe, \
+ .address.in6.s6_addr[1] = 0x80, \
+ .prefixlen = 64, \
+ })
+/* 224.0.0.0/4 */
+#define IN_ADDR_PREFIX_IPV4_MULTICAST \
+ ((struct in_addr_prefix) { \
+ .family = AF_INET, \
+ .address.in.s_addr = htobe32((UINT32_C(224) << 24)), \
+ .prefixlen = 4, \
+ })
+/* ff00::/8 */
+#define IN_ADDR_PREFIX_IPV6_MULTICAST \
+ ((struct in_addr_prefix) { \
+ .family = AF_INET6, \
+ .address.in6.s6_addr[0] = 0xff, \
+ .prefixlen = 8, \
+ })
+
+static void in_addr_prefix_hash_func(const struct in_addr_prefix *a, struct siphash *state) {
+ assert(a);
+ assert(state);
+
+ siphash24_compress(&a->family, sizeof(a->family), state);
+ siphash24_compress(&a->prefixlen, sizeof(a->prefixlen), state);
+ siphash24_compress(&a->address, FAMILY_ADDRESS_SIZE(a->family), state);
+}
+
+static int in_addr_prefix_compare_func(const struct in_addr_prefix *x, const struct in_addr_prefix *y) {
+ int r;
+
+ assert(x);
+ assert(y);
+
+ r = CMP(x->family, y->family);
+ if (r != 0)
+ return r;
+
+ r = CMP(x->prefixlen, y->prefixlen);
+ if (r != 0)
+ return r;
+
+ return memcmp(&x->address, &y->address, FAMILY_ADDRESS_SIZE(x->family));
+}
+
+DEFINE_HASH_OPS(in_addr_prefix_hash_ops, struct in_addr_prefix, in_addr_prefix_hash_func, in_addr_prefix_compare_func);
+DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(in_addr_prefix_hash_ops_free, struct in_addr_prefix, in_addr_prefix_hash_func, in_addr_prefix_compare_func, free);
+
+int in_addr_prefix_add(Set **prefixes, const struct in_addr_prefix *prefix) {
+ struct in_addr_prefix *copy;
+
+ assert(prefixes);
+ assert(prefix);
+ assert(IN_SET(prefix->family, AF_INET, AF_INET6));
+
+ copy = newdup(struct in_addr_prefix, prefix, 1);
+ if (!copy)
+ return -ENOMEM;
+
+ (void) in_addr_mask(copy->family, &copy->address, copy->prefixlen);
+ return set_ensure_consume(prefixes, &in_addr_prefix_hash_ops_free, copy);
+}
+
+int in_addr_prefixes_reduce(Set *prefixes) {
+ uint32_t ipv4_prefixlen_bits = 0;
+ uint64_t ipv6_prefixlen_bits[128 / sizeof(uint64_t)] = {};
+ uint8_t ipv4_prefixlens[32] = {}, ipv6_prefixlens[128] = {};
+ bool ipv4_has_any = false, ipv6_has_any = false;
+ size_t ipv4_n_prefixlens = 0, ipv6_n_prefixlens = 0;
+ struct in_addr_prefix *p;
+
+ SET_FOREACH(p, prefixes)
+ switch (p->family) {
+ case AF_INET:
+ assert(p->prefixlen <= 32);
+ if (p->prefixlen == 0)
+ ipv4_has_any = true;
+ else
+ ipv4_prefixlen_bits |= UINT32_C(1) << (p->prefixlen - 1);
+ break;
+ case AF_INET6:
+ assert(p->prefixlen <= 128);
+ if (p->prefixlen == 0)
+ ipv6_has_any = true;
+ else
+ ipv6_prefixlen_bits[(p->prefixlen - 1) / sizeof(uint64_t)] |=
+ UINT64_C(1) << ((p->prefixlen - 1) % sizeof(uint64_t));
+ break;
+ default:
+ assert_not_reached();
+ }
+
+ if (!ipv4_has_any)
+ for (size_t i = 0; i < 32; i++)
+ if (ipv4_prefixlen_bits & (UINT32_C(1) << i))
+ ipv4_prefixlens[ipv4_n_prefixlens++] = i + 1;
+
+ if (!ipv6_has_any)
+ for (size_t i = 0; i < 128; i++)
+ if (ipv6_prefixlen_bits[i / sizeof(uint64_t)] &
+ (UINT64_C(1) << (i % sizeof(uint64_t))))
+ ipv6_prefixlens[ipv6_n_prefixlens++] = i + 1;
+
+ SET_FOREACH(p, prefixes) {
+ uint8_t *prefixlens;
+ bool covered;
+ size_t *n;
+
+ if (p->prefixlen == 0)
+ continue;
+
+ switch (p->family) {
+ case AF_INET:
+ prefixlens = ipv4_prefixlens;
+ n = &ipv4_n_prefixlens;
+ covered = ipv4_has_any;
+ break;
+ case AF_INET6:
+ prefixlens = ipv6_prefixlens;
+ n = &ipv6_n_prefixlens;
+ covered = ipv6_has_any;
+ break;
+ default:
+ assert_not_reached();
+ }
+
+ for (size_t i = 0; i < *n; i++) {
+ struct in_addr_prefix tmp;
+
+ if (covered)
+ break;
+
+ if (prefixlens[i] >= p->prefixlen)
+ break;
+
+ tmp = *p;
+ tmp.prefixlen = prefixlens[i];
+ (void) in_addr_mask(tmp.family, &tmp.address, tmp.prefixlen);
+
+ covered = set_contains(prefixes, &tmp);
+ }
+
+ if (covered)
+ free(set_remove(prefixes, p));
+ }
+
+ return 0;
+}
+
+int in_addr_prefixes_merge(Set **dest, Set *src) {
+ struct in_addr_prefix *p;
+ int r;
+
+ assert(dest);
+
+ SET_FOREACH(p, src) {
+ r = in_addr_prefix_add(dest, p);
+ if (r < 0)
+ return r;
+ }
+
+ return 0;
+}
+
+bool in_addr_prefixes_is_any(Set *prefixes) {
+ return
+ set_contains(prefixes, &IN_ADDR_PREFIX_IPV4_ANY) &&
+ set_contains(prefixes, &IN_ADDR_PREFIX_IPV6_ANY);
+}
+
+int config_parse_in_addr_prefixes(
+ const char *unit,
+ const char *filename,
+ unsigned line,
+ const char *section,
+ unsigned section_line,
+ const char *lvalue,
+ int ltype,
+ const char *rvalue,
+ void *data,
+ void *userdata) {
+
+ Set **prefixes = ASSERT_PTR(data);
+ int r;
+
+ assert(IN_SET(ltype, AF_UNSPEC, AF_INET, AF_INET6));
+
+ if (isempty(rvalue)) {
+ *prefixes = set_free(*prefixes);
+ return 0;
+ }
+
+ for (const char *p = rvalue;;) {
+ _cleanup_free_ char *word = NULL;
+
+ r = extract_first_word(&p, &word, NULL, 0);
+ if (r == -ENOMEM)
+ return log_oom();
+ if (r < 0) {
+ log_syntax(unit, LOG_WARNING, filename, line, r, "Invalid syntax, ignoring: %s", rvalue);
+ return 0;
+ }
+ if (r == 0)
+ return 0;
+
+ if (streq(word, "any")) {
+ /* "any" is a shortcut for 0.0.0.0/0 and ::/0 */
+
+ if (ltype != AF_INET6) {
+ r = in_addr_prefix_add(prefixes, &IN_ADDR_PREFIX_IPV4_ANY);
+ if (r < 0)
+ return log_oom();
+ }
+
+ if (ltype != AF_INET) {
+ r = in_addr_prefix_add(prefixes, &IN_ADDR_PREFIX_IPV6_ANY);
+ if (r < 0)
+ return log_oom();
+ }
+
+ } else if (is_localhost(word)) {
+ /* "localhost" is a shortcut for 127.0.0.0/8 and ::1/128 */
+
+ if (ltype != AF_INET6) {
+ r = in_addr_prefix_add(prefixes, &IN_ADDR_PREFIX_IPV4_LOCALHOST);
+ if (r < 0)
+ return log_oom();
+ }
+
+ if (ltype != AF_INET) {
+ r = in_addr_prefix_add(prefixes, &IN_ADDR_PREFIX_IPV6_LOCALHOST);
+ if (r < 0)
+ return log_oom();
+ }
+
+ } else if (streq(word, "link-local")) {
+ /* "link-local" is a shortcut for 169.254.0.0/16 and fe80::/64 */
+
+ if (ltype != AF_INET6) {
+ r = in_addr_prefix_add(prefixes, &IN_ADDR_PREFIX_IPV4_LINKLOCAL);
+ if (r < 0)
+ return log_oom();
+ }
+
+ if (ltype != AF_INET) {
+ r = in_addr_prefix_add(prefixes, &IN_ADDR_PREFIX_IPV6_LINKLOCAL);
+ if (r < 0)
+ return log_oom();
+ }
+
+ } else if (streq(word, "multicast")) {
+ /* "multicast" is a shortcut for 224.0.0.0/4 and ff00::/8 */
+
+ if (ltype != AF_INET6) {
+ r = in_addr_prefix_add(prefixes, &IN_ADDR_PREFIX_IPV4_MULTICAST);
+ if (r < 0)
+ return log_oom();
+ }
+
+ if (ltype != AF_INET) {
+ r = in_addr_prefix_add(prefixes, &IN_ADDR_PREFIX_IPV6_MULTICAST);
+ if (r < 0)
+ return log_oom();
+ }
+
+ } else {
+ struct in_addr_prefix a;
+
+ if (ltype == AF_UNSPEC)
+ r = in_addr_prefix_from_string_auto(word, &a.family, &a.address, &a.prefixlen);
+ else {
+ a.family = ltype;
+ r = in_addr_prefix_from_string(word, a.family, &a.address, &a.prefixlen);
+ }
+ if (r < 0) {
+ log_syntax(unit, LOG_WARNING, filename, line, r,
+ "Invalid address prefix is specified in [%s] %s=, ignoring assignment: %s",
+ section, lvalue, word);
+ continue;
+ }
+
+ r = in_addr_prefix_add(prefixes, &a);
+ if (r < 0)
+ return log_oom();
+ }
+ }
+}
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