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-rw-r--r--src/shared/dns-domain.c987
1 files changed, 850 insertions, 137 deletions
diff --git a/src/shared/dns-domain.c b/src/shared/dns-domain.c
index 20a44ce4e1..892f0aadf5 100644
--- a/src/shared/dns-domain.c
+++ b/src/shared/dns-domain.c
@@ -1,5 +1,3 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
/***
This file is part of systemd.
@@ -24,7 +22,22 @@
#include <stringprep.h>
#endif
+#include <endian.h>
+#include <netinet/in.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/socket.h>
+
+#include "alloc-util.h"
#include "dns-domain.h"
+#include "hashmap.h"
+#include "hexdecoct.h"
+#include "in-addr-util.h"
+#include "macro.h"
+#include "parse-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "utf8.h"
int dns_label_unescape(const char **name, char *dest, size_t sz) {
const char *n;
@@ -33,7 +46,6 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) {
assert(name);
assert(*name);
- assert(dest);
n = *name;
d = dest;
@@ -47,12 +59,12 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) {
if (*n == 0)
break;
- if (sz <= 0)
- return -ENOSPC;
-
if (r >= DNS_LABEL_MAX)
return -EINVAL;
+ if (sz <= 0)
+ return -ENOBUFS;
+
if (*n == '\\') {
/* Escaped character */
@@ -64,9 +76,12 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) {
else if (*n == '\\' || *n == '.') {
/* Escaped backslash or dot */
- *(d++) = *(n++);
+
+ if (d)
+ *(d++) = *n;
sz--;
r++;
+ n++;
} else if (n[0] >= '0' && n[0] <= '9') {
unsigned k;
@@ -81,11 +96,17 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) {
((unsigned) (n[1] - '0') * 10) +
((unsigned) (n[2] - '0'));
- /* Don't allow CC characters or anything that doesn't fit in 8bit */
- if (k < ' ' || k > 255 || k == 127)
+ /* Don't allow anything that doesn't
+ * fit in 8bit. Note that we do allow
+ * control characters, as some servers
+ * (e.g. cloudflare) are happy to
+ * generate labels with them
+ * inside. */
+ if (k > 255)
return -EINVAL;
- *(d++) = (char) k;
+ if (d)
+ *(d++) = (char) k;
sz--;
r++;
@@ -96,9 +117,12 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) {
} else if ((uint8_t) *n >= (uint8_t) ' ' && *n != 127) {
/* Normal character */
- *(d++) = *(n++);
+
+ if (d)
+ *(d++) = *n;
sz--;
r++;
+ n++;
} else
return -EINVAL;
}
@@ -107,37 +131,113 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) {
if (r == 0 && *n)
return -EINVAL;
- if (sz >= 1)
+ /* More than one trailing dot? */
+ if (*n == '.')
+ return -EINVAL;
+
+ if (sz >= 1 && d)
*d = 0;
*name = n;
return r;
}
-int dns_label_escape(const char *p, size_t l, char **ret) {
- _cleanup_free_ char *s = NULL;
- char *q;
+/* @label_terminal: terminal character of a label, updated to point to the terminal character of
+ * the previous label (always skipping one dot) or to NULL if there are no more
+ * labels. */
+int dns_label_unescape_suffix(const char *name, const char **label_terminal, char *dest, size_t sz) {
+ const char *terminal;
int r;
- assert(p);
- assert(ret);
+ assert(name);
+ assert(label_terminal);
+ assert(dest);
+
+ /* no more labels */
+ if (!*label_terminal) {
+ if (sz >= 1)
+ *dest = 0;
+
+ return 0;
+ }
+
+ terminal = *label_terminal;
+ assert(*terminal == '.' || *terminal == 0);
+
+ /* Skip current terminal character (and accept domain names ending it ".") */
+ if (*terminal == 0)
+ terminal--;
+ if (terminal >= name && *terminal == '.')
+ terminal--;
+
+ /* Point name to the last label, and terminal to the preceding terminal symbol (or make it a NULL pointer) */
+ for (;;) {
+ if (terminal < name) {
+ /* Reached the first label, so indicate that there are no more */
+ terminal = NULL;
+ break;
+ }
+
+ /* Find the start of the last label */
+ if (*terminal == '.') {
+ const char *y;
+ unsigned slashes = 0;
+
+ for (y = terminal - 1; y >= name && *y == '\\'; y--)
+ slashes++;
+
+ if (slashes % 2 == 0) {
+ /* The '.' was not escaped */
+ name = terminal + 1;
+ break;
+ } else {
+ terminal = y;
+ continue;
+ }
+ }
+
+ terminal--;
+ }
+
+ r = dns_label_unescape(&name, dest, sz);
+ if (r < 0)
+ return r;
+
+ *label_terminal = terminal;
+
+ return r;
+}
- if (l > DNS_LABEL_MAX)
+int dns_label_escape(const char *p, size_t l, char *dest, size_t sz) {
+ char *q;
+
+ /* DNS labels must be between 1 and 63 characters long. A
+ * zero-length label does not exist. See RFC 2182, Section
+ * 11. */
+
+ if (l <= 0 || l > DNS_LABEL_MAX)
return -EINVAL;
+ if (sz < 1)
+ return -ENOBUFS;
- s = malloc(l * 4 + 1);
- if (!s)
- return -ENOMEM;
+ assert(p);
+ assert(dest);
- q = s;
+ q = dest;
while (l > 0) {
if (*p == '.' || *p == '\\') {
/* Dot or backslash */
+
+ if (sz < 3)
+ return -ENOBUFS;
+
*(q++) = '\\';
*(q++) = *p;
+ sz -= 2;
+
} else if (*p == '_' ||
*p == '-' ||
(*p >= '0' && *p <= '9') ||
@@ -145,25 +245,55 @@ int dns_label_escape(const char *p, size_t l, char **ret) {
(*p >= 'A' && *p <= 'Z')) {
/* Proper character */
+
+ if (sz < 2)
+ return -ENOBUFS;
+
*(q++) = *p;
- } else if ((uint8_t) *p >= (uint8_t) ' ' && *p != 127) {
+ sz -= 1;
+
+ } else {
/* Everything else */
+
+ if (sz < 5)
+ return -ENOBUFS;
+
*(q++) = '\\';
*(q++) = '0' + (char) ((uint8_t) *p / 100);
*(q++) = '0' + (char) (((uint8_t) *p / 10) % 10);
*(q++) = '0' + (char) ((uint8_t) *p % 10);
- } else
- return -EINVAL;
+ sz -= 4;
+ }
p++;
l--;
}
*q = 0;
+ return (int) (q - dest);
+}
+
+int dns_label_escape_new(const char *p, size_t l, char **ret) {
+ _cleanup_free_ char *s = NULL;
+ int r;
+
+ assert(p);
+ assert(ret);
+
+ if (l <= 0 || l > DNS_LABEL_MAX)
+ return -EINVAL;
+
+ s = new(char, DNS_LABEL_ESCAPED_MAX);
+ if (!s)
+ return -ENOMEM;
+
+ r = dns_label_escape(p, l, s, DNS_LABEL_ESCAPED_MAX);
+ if (r < 0)
+ return r;
+
*ret = s;
- r = q - s;
s = NULL;
return r;
@@ -172,32 +302,52 @@ int dns_label_escape(const char *p, size_t l, char **ret) {
int dns_label_apply_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max) {
#ifdef HAVE_LIBIDN
_cleanup_free_ uint32_t *input = NULL;
- size_t input_size;
+ size_t input_size, l;
const char *p;
bool contains_8bit = false;
+ char buffer[DNS_LABEL_MAX+1];
assert(encoded);
assert(decoded);
- assert(decoded_max >= DNS_LABEL_MAX);
+
+ /* Converts an U-label into an A-label */
if (encoded_size <= 0)
- return 0;
+ return -EINVAL;
for (p = encoded; p < encoded + encoded_size; p++)
if ((uint8_t) *p > 127)
contains_8bit = true;
- if (!contains_8bit)
+ if (!contains_8bit) {
+ if (encoded_size > DNS_LABEL_MAX)
+ return -EINVAL;
+
return 0;
+ }
input = stringprep_utf8_to_ucs4(encoded, encoded_size, &input_size);
if (!input)
return -ENOMEM;
- if (idna_to_ascii_4i(input, input_size, decoded, 0) != 0)
+ if (idna_to_ascii_4i(input, input_size, buffer, 0) != 0)
+ return -EINVAL;
+
+ l = strlen(buffer);
+
+ /* Verify that the result is not longer than one DNS label. */
+ if (l <= 0 || l > DNS_LABEL_MAX)
return -EINVAL;
+ if (l > decoded_max)
+ return -ENOBUFS;
- return strlen(decoded);
+ memcpy(decoded, buffer, l);
+
+ /* If there's room, append a trailing NUL byte, but only then */
+ if (decoded_max > l)
+ decoded[l] = 0;
+
+ return (int) l;
#else
return 0;
#endif
@@ -211,11 +361,14 @@ int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded,
uint32_t *output = NULL;
size_t w;
- /* To be invoked after unescaping */
+ /* To be invoked after unescaping. Converts an A-label into an U-label. */
assert(encoded);
assert(decoded);
+ if (encoded_size <= 0 || encoded_size > DNS_LABEL_MAX)
+ return -EINVAL;
+
if (encoded_size < sizeof(IDNA_ACE_PREFIX)-1)
return 0;
@@ -235,30 +388,39 @@ int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded,
if (!result)
return -ENOMEM;
if (w <= 0)
- return 0;
- if (w+1 > decoded_max)
return -EINVAL;
+ if (w > decoded_max)
+ return -ENOBUFS;
+
+ memcpy(decoded, result, w);
+
+ /* Append trailing NUL byte if there's space, but only then. */
+ if (decoded_max > w)
+ decoded[w] = 0;
- memcpy(decoded, result, w+1);
return w;
#else
return 0;
#endif
}
-int dns_name_normalize(const char *s, char **_ret) {
+int dns_name_concat(const char *a, const char *b, char **_ret) {
_cleanup_free_ char *ret = NULL;
size_t n = 0, allocated = 0;
- const char *p = s;
+ const char *p;
bool first = true;
int r;
- assert(s);
+ if (a)
+ p = a;
+ else if (b) {
+ p = b;
+ b = NULL;
+ } else
+ goto finish;
for (;;) {
- _cleanup_free_ char *t = NULL;
char label[DNS_LABEL_MAX];
- int k;
r = dns_label_unescape(&p, label, sizeof(label));
if (r < 0)
@@ -266,40 +428,60 @@ int dns_name_normalize(const char *s, char **_ret) {
if (r == 0) {
if (*p != 0)
return -EINVAL;
+
+ if (b) {
+ /* Now continue with the second string, if there is one */
+ p = b;
+ b = NULL;
+ continue;
+ }
+
break;
}
- k = dns_label_undo_idna(label, r, label, sizeof(label));
- if (k < 0)
- return k;
- if (k > 0)
- r = k;
+ if (_ret) {
+ if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX))
+ return -ENOMEM;
- r = dns_label_escape(label, r, &t);
- if (r < 0)
- return r;
+ r = dns_label_escape(label, r, ret + n + !first, DNS_LABEL_ESCAPED_MAX);
+ if (r < 0)
+ return r;
- if (!GREEDY_REALLOC(ret, allocated, n + !first + strlen(t) + 1))
- return -ENOMEM;
+ if (!first)
+ ret[n] = '.';
+ } else {
+ char escaped[DNS_LABEL_ESCAPED_MAX];
+
+ r = dns_label_escape(label, r, escaped, sizeof(escaped));
+ if (r < 0)
+ return r;
+ }
if (!first)
- ret[n++] = '.';
+ n++;
else
first = false;
- memcpy(ret + n, t, r);
n += r;
}
- if (n > DNS_NAME_MAX)
+finish:
+ if (n > DNS_HOSTNAME_MAX)
return -EINVAL;
- if (!GREEDY_REALLOC(ret, allocated, n + 1))
- return -ENOMEM;
+ if (_ret) {
+ if (n == 0) {
+ /* Nothing appended? If so, generate at least a single dot, to indicate the DNS root domain */
+ if (!GREEDY_REALLOC(ret, allocated, 2))
+ return -ENOMEM;
- ret[n] = 0;
+ ret[n++] = '.';
+ } else {
+ if (!GREEDY_REALLOC(ret, allocated, n + 1))
+ return -ENOMEM;
+ }
- if (_ret) {
+ ret[n] = 0;
*_ret = ret;
ret = NULL;
}
@@ -307,65 +489,52 @@ int dns_name_normalize(const char *s, char **_ret) {
return 0;
}
-unsigned long dns_name_hash_func(const void *s, const uint8_t hash_key[HASH_KEY_SIZE]) {
+void dns_name_hash_func(const void *s, struct siphash *state) {
const char *p = s;
- unsigned long ul = hash_key[0];
int r;
assert(p);
- while (*p) {
+ for (;;) {
char label[DNS_LABEL_MAX+1];
- int k;
r = dns_label_unescape(&p, label, sizeof(label));
if (r < 0)
break;
-
- k = dns_label_undo_idna(label, r, label, sizeof(label));
- if (k < 0)
+ if (r == 0)
break;
- if (k > 0)
- r = k;
- label[r] = 0;
- ascii_strlower(label);
-
- ul = ul * hash_key[1] + ul + string_hash_func(label, hash_key);
+ ascii_strlower_n(label, r);
+ siphash24_compress(label, r, state);
+ siphash24_compress_byte(0, state); /* make sure foobar and foo.bar result in different hashes */
}
- return ul;
+ /* enforce that all names are terminated by the empty label */
+ string_hash_func("", state);
}
int dns_name_compare_func(const void *a, const void *b) {
- const char *x = a, *y = b;
- int r, q, k, w;
+ const char *x, *y;
+ int r, q;
assert(a);
assert(b);
+ x = (const char *) a + strlen(a);
+ y = (const char *) b + strlen(b);
+
for (;;) {
- char la[DNS_LABEL_MAX+1], lb[DNS_LABEL_MAX+1];
+ char la[DNS_LABEL_MAX], lb[DNS_LABEL_MAX];
- if (*x == 0 && *y == 0)
+ if (x == NULL && y == NULL)
return 0;
- r = dns_label_unescape(&x, la, sizeof(la));
- q = dns_label_unescape(&y, lb, sizeof(lb));
+ r = dns_label_unescape_suffix(a, &x, la, sizeof(la));
+ q = dns_label_unescape_suffix(b, &y, lb, sizeof(lb));
if (r < 0 || q < 0)
return r - q;
- k = dns_label_undo_idna(la, r, la, sizeof(la));
- w = dns_label_undo_idna(lb, q, lb, sizeof(lb));
- if (k < 0 || w < 0)
- return k - w;
- if (k > 0)
- r = k;
- if (w > 0)
- r = w;
-
- la[r] = lb[q] = 0;
- r = strcasecmp(la, lb);
+ r = ascii_strcasecmp_nn(la, r, lb, q);
if (r != 0)
return r;
}
@@ -377,45 +546,35 @@ const struct hash_ops dns_name_hash_ops = {
};
int dns_name_equal(const char *x, const char *y) {
- int r, q, k, w;
+ int r, q;
assert(x);
assert(y);
for (;;) {
- char la[DNS_LABEL_MAX+1], lb[DNS_LABEL_MAX+1];
-
- if (*x == 0 && *y == 0)
- return true;
+ char la[DNS_LABEL_MAX], lb[DNS_LABEL_MAX];
r = dns_label_unescape(&x, la, sizeof(la));
if (r < 0)
return r;
- k = dns_label_undo_idna(la, r, la, sizeof(la));
- if (k < 0)
- return k;
- if (k > 0)
- r = k;
-
q = dns_label_unescape(&y, lb, sizeof(lb));
if (q < 0)
return q;
- w = dns_label_undo_idna(lb, q, lb, sizeof(lb));
- if (w < 0)
- return w;
- if (w > 0)
- q = w;
-
- la[r] = lb[q] = 0;
- if (strcasecmp(la, lb))
+
+ if (r != q)
+ return false;
+ if (r == 0)
+ return true;
+
+ if (ascii_strcasecmp_n(la, lb, r) != 0)
return false;
}
}
int dns_name_endswith(const char *name, const char *suffix) {
const char *n, *s, *saved_n = NULL;
- int r, q, k, w;
+ int r, q;
assert(name);
assert(suffix);
@@ -424,16 +583,11 @@ int dns_name_endswith(const char *name, const char *suffix) {
s = suffix;
for (;;) {
- char ln[DNS_LABEL_MAX+1], ls[DNS_LABEL_MAX+1];
+ char ln[DNS_LABEL_MAX], ls[DNS_LABEL_MAX];
r = dns_label_unescape(&n, ln, sizeof(ln));
if (r < 0)
return r;
- k = dns_label_undo_idna(ln, r, ln, sizeof(ln));
- if (k < 0)
- return k;
- if (k > 0)
- r = k;
if (!saved_n)
saved_n = n;
@@ -441,20 +595,13 @@ int dns_name_endswith(const char *name, const char *suffix) {
q = dns_label_unescape(&s, ls, sizeof(ls));
if (q < 0)
return q;
- w = dns_label_undo_idna(ls, q, ls, sizeof(ls));
- if (w < 0)
- return w;
- if (w > 0)
- q = w;
if (r == 0 && q == 0)
return true;
if (r == 0 && saved_n == n)
return false;
- ln[r] = ls[q] = 0;
-
- if (r != q || strcasecmp(ln, ls)) {
+ if (r != q || ascii_strcasecmp_n(ln, ls, r) != 0) {
/* Not the same, let's jump back, and try with the next label again */
s = suffix;
@@ -464,6 +611,113 @@ int dns_name_endswith(const char *name, const char *suffix) {
}
}
+int dns_name_startswith(const char *name, const char *prefix) {
+ const char *n, *p;
+ int r, q;
+
+ assert(name);
+ assert(prefix);
+
+ n = name;
+ p = prefix;
+
+ for (;;) {
+ char ln[DNS_LABEL_MAX], lp[DNS_LABEL_MAX];
+
+ r = dns_label_unescape(&p, lp, sizeof(lp));
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return true;
+
+ q = dns_label_unescape(&n, ln, sizeof(ln));
+ if (q < 0)
+ return q;
+
+ if (r != q)
+ return false;
+ if (ascii_strcasecmp_n(ln, lp, r) != 0)
+ return false;
+ }
+}
+
+int dns_name_change_suffix(const char *name, const char *old_suffix, const char *new_suffix, char **ret) {
+ const char *n, *s, *saved_before = NULL, *saved_after = NULL, *prefix;
+ int r, q;
+
+ assert(name);
+ assert(old_suffix);
+ assert(new_suffix);
+ assert(ret);
+
+ n = name;
+ s = old_suffix;
+
+ for (;;) {
+ char ln[DNS_LABEL_MAX], ls[DNS_LABEL_MAX];
+
+ if (!saved_before)
+ saved_before = n;
+
+ r = dns_label_unescape(&n, ln, sizeof(ln));
+ if (r < 0)
+ return r;
+
+ if (!saved_after)
+ saved_after = n;
+
+ q = dns_label_unescape(&s, ls, sizeof(ls));
+ if (q < 0)
+ return q;
+
+ if (r == 0 && q == 0)
+ break;
+ if (r == 0 && saved_after == n) {
+ *ret = NULL; /* doesn't match */
+ return 0;
+ }
+
+ if (r != q || ascii_strcasecmp_n(ln, ls, r) != 0) {
+
+ /* Not the same, let's jump back, and try with the next label again */
+ s = old_suffix;
+ n = saved_after;
+ saved_after = saved_before = NULL;
+ }
+ }
+
+ /* Found it! Now generate the new name */
+ prefix = strndupa(name, saved_before - name);
+
+ r = dns_name_concat(prefix, new_suffix, ret);
+ if (r < 0)
+ return r;
+
+ return 1;
+}
+
+int dns_name_between(const char *a, const char *b, const char *c) {
+ int n;
+
+ /* Determine if b is strictly greater than a and strictly smaller than c.
+ We consider the order of names to be circular, so that if a is
+ strictly greater than c, we consider b to be between them if it is
+ either greater than a or smaller than c. This is how the canonical
+ DNS name order used in NSEC records work. */
+
+ n = dns_name_compare_func(a, c);
+ if (n == 0)
+ return -EINVAL;
+ else if (n < 0)
+ /* a<---b--->c */
+ return dns_name_compare_func(a, b) < 0 &&
+ dns_name_compare_func(b, c) < 0;
+ else
+ /* <--b--c a--b--> */
+ return dns_name_compare_func(b, c) < 0 ||
+ dns_name_compare_func(a, b) < 0;
+}
+
int dns_name_reverse(int family, const union in_addr_union *a, char **ret) {
const uint8_t *p;
int r;
@@ -580,34 +834,493 @@ int dns_name_address(const char *p, int *family, union in_addr_union *address) {
return 0;
}
-int dns_name_root(const char *name) {
- char label[DNS_LABEL_MAX+1];
- int r;
+bool dns_name_is_root(const char *name) {
assert(name);
- r = dns_label_unescape(&name, label, sizeof(label));
- if (r < 0)
- return r;
+ /* There are exactly two ways to encode the root domain name:
+ * as empty string, or with a single dot. */
- return r == 0 && *name == 0;
+ return STR_IN_SET(name, "", ".");
}
-int dns_name_single_label(const char *name) {
- char label[DNS_LABEL_MAX+1];
+bool dns_name_is_single_label(const char *name) {
int r;
assert(name);
- r = dns_label_unescape(&name, label, sizeof(label));
+ r = dns_name_parent(&name);
+ if (r <= 0)
+ return false;
+
+ return dns_name_is_root(name);
+}
+
+/* Encode a domain name according to RFC 1035 Section 3.1, without compression */
+int dns_name_to_wire_format(const char *domain, uint8_t *buffer, size_t len, bool canonical) {
+ uint8_t *label_length, *out;
+ int r;
+
+ assert(domain);
+ assert(buffer);
+
+ out = buffer;
+
+ do {
+ /* Reserve a byte for label length */
+ if (len <= 0)
+ return -ENOBUFS;
+ len--;
+ label_length = out;
+ out++;
+
+ /* Convert and copy a single label. Note that
+ * dns_label_unescape() returns 0 when it hits the end
+ * of the domain name, which we rely on here to encode
+ * the trailing NUL byte. */
+ r = dns_label_unescape(&domain, (char *) out, len);
+ if (r < 0)
+ return r;
+
+ /* Optionally, output the name in DNSSEC canonical
+ * format, as described in RFC 4034, section 6.2. Or
+ * in other words: in lower-case. */
+ if (canonical)
+ ascii_strlower_n((char*) out, (size_t) r);
+
+ /* Fill label length, move forward */
+ *label_length = r;
+ out += r;
+ len -= r;
+
+ } while (r != 0);
+
+ /* Verify the maximum size of the encoded name. The trailing
+ * dot + NUL byte account are included this time, hence
+ * compare against DNS_HOSTNAME_MAX + 2 (which is 255) this
+ * time. */
+ if (out - buffer > DNS_HOSTNAME_MAX + 2)
+ return -EINVAL;
+
+ return out - buffer;
+}
+
+static bool srv_type_label_is_valid(const char *label, size_t n) {
+ size_t k;
+
+ assert(label);
+
+ if (n < 2) /* Label needs to be at least 2 chars long */
+ return false;
+
+ if (label[0] != '_') /* First label char needs to be underscore */
+ return false;
+
+ /* Second char must be a letter */
+ if (!(label[1] >= 'A' && label[1] <= 'Z') &&
+ !(label[1] >= 'a' && label[1] <= 'z'))
+ return false;
+
+ /* Third and further chars must be alphanumeric or a hyphen */
+ for (k = 2; k < n; k++) {
+ if (!(label[k] >= 'A' && label[k] <= 'Z') &&
+ !(label[k] >= 'a' && label[k] <= 'z') &&
+ !(label[k] >= '0' && label[k] <= '9') &&
+ label[k] != '-')
+ return false;
+ }
+
+ return true;
+}
+
+bool dns_srv_type_is_valid(const char *name) {
+ unsigned c = 0;
+ int r;
+
+ if (!name)
+ return false;
+
+ for (;;) {
+ char label[DNS_LABEL_MAX];
+
+ /* This more or less implements RFC 6335, Section 5.1 */
+
+ r = dns_label_unescape(&name, label, sizeof(label));
+ if (r < 0)
+ return false;
+ if (r == 0)
+ break;
+
+ if (c >= 2)
+ return false;
+
+ if (!srv_type_label_is_valid(label, r))
+ return false;
+
+ c++;
+ }
+
+ return c == 2; /* exactly two labels */
+}
+
+bool dns_service_name_is_valid(const char *name) {
+ size_t l;
+
+ /* This more or less implements RFC 6763, Section 4.1.1 */
+
+ if (!name)
+ return false;
+
+ if (!utf8_is_valid(name))
+ return false;
+
+ if (string_has_cc(name, NULL))
+ return false;
+
+ l = strlen(name);
+ if (l <= 0)
+ return false;
+ if (l > 63)
+ return false;
+
+ return true;
+}
+
+int dns_service_join(const char *name, const char *type, const char *domain, char **ret) {
+ char escaped[DNS_LABEL_ESCAPED_MAX];
+ _cleanup_free_ char *n = NULL;
+ int r;
+
+ assert(type);
+ assert(domain);
+ assert(ret);
+
+ if (!dns_srv_type_is_valid(type))
+ return -EINVAL;
+
+ if (!name)
+ return dns_name_concat(type, domain, ret);
+
+ if (!dns_service_name_is_valid(name))
+ return -EINVAL;
+
+ r = dns_label_escape(name, strlen(name), escaped, sizeof(escaped));
if (r < 0)
return r;
- if (r == 0)
- return 0;
- r = dns_label_unescape(&name, label, sizeof(label));
+ r = dns_name_concat(type, domain, &n);
+ if (r < 0)
+ return r;
+
+ return dns_name_concat(escaped, n, ret);
+}
+
+static bool dns_service_name_label_is_valid(const char *label, size_t n) {
+ char *s;
+
+ assert(label);
+
+ if (memchr(label, 0, n))
+ return false;
+
+ s = strndupa(label, n);
+ return dns_service_name_is_valid(s);
+}
+
+int dns_service_split(const char *joined, char **_name, char **_type, char **_domain) {
+ _cleanup_free_ char *name = NULL, *type = NULL, *domain = NULL;
+ const char *p = joined, *q = NULL, *d = NULL;
+ char a[DNS_LABEL_MAX], b[DNS_LABEL_MAX], c[DNS_LABEL_MAX];
+ int an, bn, cn, r;
+ unsigned x = 0;
+
+ assert(joined);
+
+ /* Get first label from the full name */
+ an = dns_label_unescape(&p, a, sizeof(a));
+ if (an < 0)
+ return an;
+
+ if (an > 0) {
+ x++;
+
+ /* If there was a first label, try to get the second one */
+ bn = dns_label_unescape(&p, b, sizeof(b));
+ if (bn < 0)
+ return bn;
+
+ if (bn > 0) {
+ x++;
+
+ /* If there was a second label, try to get the third one */
+ q = p;
+ cn = dns_label_unescape(&p, c, sizeof(c));
+ if (cn < 0)
+ return cn;
+
+ if (cn > 0)
+ x++;
+ } else
+ cn = 0;
+ } else
+ an = 0;
+
+ if (x >= 2 && srv_type_label_is_valid(b, bn)) {
+
+ if (x >= 3 && srv_type_label_is_valid(c, cn)) {
+
+ if (dns_service_name_label_is_valid(a, an)) {
+ /* OK, got <name> . <type> . <type2> . <domain> */
+
+ name = strndup(a, an);
+ if (!name)
+ return -ENOMEM;
+
+ type = strjoin(b, ".", c, NULL);
+ if (!type)
+ return -ENOMEM;
+
+ d = p;
+ goto finish;
+ }
+
+ } else if (srv_type_label_is_valid(a, an)) {
+
+ /* OK, got <type> . <type2> . <domain> */
+
+ name = NULL;
+
+ type = strjoin(a, ".", b, NULL);
+ if (!type)
+ return -ENOMEM;
+
+ d = q;
+ goto finish;
+ }
+ }
+
+ name = NULL;
+ type = NULL;
+ d = joined;
+
+finish:
+ r = dns_name_normalize(d, &domain);
if (r < 0)
return r;
- return r == 0 && *name == 0;
+ if (_domain) {
+ *_domain = domain;
+ domain = NULL;
+ }
+
+ if (_type) {
+ *_type = type;
+ type = NULL;
+ }
+
+ if (_name) {
+ *_name = name;
+ name = NULL;
+ }
+
+ return 0;
+}
+
+static int dns_name_build_suffix_table(const char *name, const char*table[]) {
+ const char *p;
+ unsigned n = 0;
+ int r;
+
+ assert(name);
+ assert(table);
+
+ p = name;
+ for (;;) {
+ if (n > DNS_N_LABELS_MAX)
+ return -EINVAL;
+
+ table[n] = p;
+ r = dns_name_parent(&p);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ break;
+
+ n++;
+ }
+
+ return (int) n;
+}
+
+int dns_name_suffix(const char *name, unsigned n_labels, const char **ret) {
+ const char* labels[DNS_N_LABELS_MAX+1];
+ int n;
+
+ assert(name);
+ assert(ret);
+
+ n = dns_name_build_suffix_table(name, labels);
+ if (n < 0)
+ return n;
+
+ if ((unsigned) n < n_labels)
+ return -EINVAL;
+
+ *ret = labels[n - n_labels];
+ return (int) (n - n_labels);
+}
+
+int dns_name_skip(const char *a, unsigned n_labels, const char **ret) {
+ int r;
+
+ assert(a);
+ assert(ret);
+
+ for (; n_labels > 0; n_labels--) {
+ r = dns_name_parent(&a);
+ if (r < 0)
+ return r;
+ if (r == 0) {
+ *ret = "";
+ return 0;
+ }
+ }
+
+ *ret = a;
+ return 1;
+}
+
+int dns_name_count_labels(const char *name) {
+ unsigned n = 0;
+ const char *p;
+ int r;
+
+ assert(name);
+
+ p = name;
+ for (;;) {
+ r = dns_name_parent(&p);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ break;
+
+ if (n >= DNS_N_LABELS_MAX)
+ return -EINVAL;
+
+ n++;
+ }
+
+ return (int) n;
+}
+
+int dns_name_equal_skip(const char *a, unsigned n_labels, const char *b) {
+ int r;
+
+ assert(a);
+ assert(b);
+
+ r = dns_name_skip(a, n_labels, &a);
+ if (r <= 0)
+ return r;
+
+ return dns_name_equal(a, b);
+}
+
+int dns_name_common_suffix(const char *a, const char *b, const char **ret) {
+ const char *a_labels[DNS_N_LABELS_MAX+1], *b_labels[DNS_N_LABELS_MAX+1];
+ int n = 0, m = 0, k = 0, r, q;
+
+ assert(a);
+ assert(b);
+ assert(ret);
+
+ /* Determines the common suffix of domain names a and b */
+
+ n = dns_name_build_suffix_table(a, a_labels);
+ if (n < 0)
+ return n;
+
+ m = dns_name_build_suffix_table(b, b_labels);
+ if (m < 0)
+ return m;
+
+ for (;;) {
+ char la[DNS_LABEL_MAX], lb[DNS_LABEL_MAX];
+ const char *x, *y;
+
+ if (k >= n || k >= m) {
+ *ret = a_labels[n - k];
+ return 0;
+ }
+
+ x = a_labels[n - 1 - k];
+ r = dns_label_unescape(&x, la, sizeof(la));
+ if (r < 0)
+ return r;
+
+ y = b_labels[m - 1 - k];
+ q = dns_label_unescape(&y, lb, sizeof(lb));
+ if (q < 0)
+ return q;
+
+ if (r != q || ascii_strcasecmp_n(la, lb, r) != 0) {
+ *ret = a_labels[n - k];
+ return 0;
+ }
+
+ k++;
+ }
+}
+
+int dns_name_apply_idna(const char *name, char **ret) {
+ _cleanup_free_ char *buf = NULL;
+ size_t n = 0, allocated = 0;
+ bool first = true;
+ int r, q;
+
+ assert(name);
+ assert(ret);
+
+ for (;;) {
+ char label[DNS_LABEL_MAX];
+
+ r = dns_label_unescape(&name, label, sizeof(label));
+ if (r < 0)
+ return r;
+ if (r == 0)
+ break;
+
+ q = dns_label_apply_idna(label, r, label, sizeof(label));
+ if (q < 0)
+ return q;
+ if (q > 0)
+ r = q;
+
+ if (!GREEDY_REALLOC(buf, allocated, n + !first + DNS_LABEL_ESCAPED_MAX))
+ return -ENOMEM;
+
+ r = dns_label_escape(label, r, buf + n + !first, DNS_LABEL_ESCAPED_MAX);
+ if (r < 0)
+ return r;
+
+ if (first)
+ first = false;
+ else
+ buf[n++] = '.';
+
+ n +=r;
+ }
+
+ if (n > DNS_HOSTNAME_MAX)
+ return -EINVAL;
+
+ if (!GREEDY_REALLOC(buf, allocated, n + 1))
+ return -ENOMEM;
+
+ buf[n] = 0;
+ *ret = buf;
+ buf = NULL;
+
+ return (int) n;
}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-07-22 23:57:17 +0000