#include "macro.h"
#include "parse-util.h"
#include "random-util.h"
+#include "string-util.h"
#include "strxcpyx.h"
#include "util.h"
assert(u);
/* Increases the network part of an address by one. Returns
- * positive it that succeeds, or 0 if this overflows. */
+ * positive if that succeeds, or -ERANGE if this overflows. */
+
+ return in_addr_prefix_nth(family, u, prefixlen, 1);
+}
+
+/*
+ * Calculates the nth prefix of size prefixlen starting from the address denoted by u.
+ *
+ * On success 1 will be returned and the calculated prefix will be available in
+ * u. In the case nth == 0 the input will be left unchanged and 1 will be returned.
+ * In case the calculation cannot be performed (invalid prefix length,
+ * overflows would occur) -ERANGE is returned. If the address family given isn't
+ * supported -EAFNOSUPPORT will be returned.
+ *
+ *
+ * Examples:
+ * - in_addr_prefix_nth(AF_INET, 192.168.0.0, 24, 2), returns 1, writes 192.168.2.0 to u
+ * - in_addr_prefix_nth(AF_INET, 192.168.0.0, 24, 0), returns 1, no data written
+ * - in_addr_prefix_nth(AF_INET, 255.255.255.0, 24, 1), returns -ERANGE, no data written
+ * - in_addr_prefix_nth(AF_INET, 255.255.255.0, 0, 1), returns -ERANGE, no data written
+ * - in_addr_prefix_nth(AF_INET6, 2001:db8, 64, 0xff00) returns 1, writes 2001:0db8:0000:ff00:: to u
+ */
+int in_addr_prefix_nth(int family, union in_addr_union *u, unsigned prefixlen, uint64_t nth) {
+ assert(u);
if (prefixlen <= 0)
- return 0;
+ return -ERANGE;
- if (family == AF_INET) {
- uint32_t c, n;
+ if (nth == 0)
+ return 1;
+ if (family == AF_INET) {
+ uint32_t c, n, t;
if (prefixlen > 32)
prefixlen = 32;
c = be32toh(u->in.s_addr);
- n = c + (1UL << (32 - prefixlen));
- if (n < c)
- return 0;
- n &= 0xFFFFFFFFUL << (32 - prefixlen);
+ t = nth << (32 - prefixlen);
+
+ /* Check for wrap */
+ if (c > UINT32_MAX - t)
+ return -ERANGE;
+
+ n = c + t;
+
+ n &= UINT32_C(0xFFFFFFFF) << (32 - prefixlen);
u->in.s_addr = htobe32(n);
return 1;
}
if (family == AF_INET6) {
- struct in6_addr add = {}, result;
+ struct in6_addr result = {};
uint8_t overflow = 0;
- unsigned i;
+ uint64_t delta; /* this assumes that we only ever have to up to 1<<64 subnets */
+ unsigned start_byte = (prefixlen - 1) / 8;
if (prefixlen > 128)
prefixlen = 128;
/* First calculate what we have to add */
- add.s6_addr[(prefixlen-1) / 8] = 1 << (7 - (prefixlen-1) % 8);
+ delta = nth << ((128 - prefixlen) % 8);
- for (i = 16; i > 0; i--) {
+ for (unsigned i = 16; i > 0; i--) {
unsigned j = i - 1;
+ unsigned d = 0;
+
+ if (j <= start_byte) {
+ int16_t t;
- result.s6_addr[j] = u->in6.s6_addr[j] + add.s6_addr[j] + overflow;
- overflow = (result.s6_addr[j] < u->in6.s6_addr[j]);
+ d = delta & 0xFF;
+ delta >>= 8;
+
+ t = u->in6.s6_addr[j] + d + overflow;
+ overflow = t > UINT8_MAX ? t - UINT8_MAX : 0;
+
+ result.s6_addr[j] = (uint8_t)t;
+ } else
+ result.s6_addr[j] = u->in6.s6_addr[j];
}
- if (overflow)
- return 0;
+ if (overflow || delta != 0)
+ return -ERANGE;
u->in6 = result;
return 1;
return in_addr_to_string(family, u, ret);
}
+int in_addr_port_ifindex_name_to_string(int family, const union in_addr_union *u, uint16_t port, int ifindex, const char *server_name, char **ret) {
+ _cleanup_free_ char *ip_str = NULL, *x = NULL;
+ int r;
+
+ assert(IN_SET(family, AF_INET, AF_INET6));
+ assert(u);
+ assert(ret);
+
+ /* Much like in_addr_to_string(), but optionally appends the zone interface index to the address, to properly
+ * handle IPv6 link-local addresses. */
+
+ r = in_addr_to_string(family, u, &ip_str);
+ if (r < 0)
+ return r;
+
+ if (family == AF_INET6) {
+ r = in_addr_is_link_local(family, u);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ ifindex = 0;
+ } else
+ ifindex = 0; /* For IPv4 address, ifindex is always ignored. */
+
+ if (port == 0 && ifindex == 0 && isempty(server_name)) {
+ *ret = TAKE_PTR(ip_str);
+ return 0;
+ }
+
+ const char *separator = isempty(server_name) ? "" : "#";
+ server_name = strempty(server_name);
+
+ if (port > 0) {
+ if (family == AF_INET6) {
+ if (ifindex > 0)
+ r = asprintf(&x, "[%s]:%"PRIu16"%%%i%s%s", ip_str, port, ifindex, separator, server_name);
+ else
+ r = asprintf(&x, "[%s]:%"PRIu16"%s%s", ip_str, port, separator, server_name);
+ } else
+ r = asprintf(&x, "%s:%"PRIu16"%s%s", ip_str, port, separator, server_name);
+ } else {
+ if (ifindex > 0)
+ r = asprintf(&x, "%s%%%i%s%s", ip_str, ifindex, separator, server_name);
+ else {
+ x = strjoin(ip_str, separator, server_name);
+ r = x ? 0 : -ENOMEM;
+ }
+ }
+ if (r < 0)
+ return -ENOMEM;
+
+ *ret = TAKE_PTR(x);
+ return 0;
+}
+
int in_addr_from_string(int family, const char *s, union in_addr_union *ret) {
union in_addr_union buffer;
assert(s);
projects / thirdparty / systemd.git / blobdiff