From bb110bc7433adeb79b4814ef2a1c04e2160be396 Mon Sep 17 00:00:00 2001 From: Luke Shumaker Date: Wed, 1 Jun 2016 15:52:09 -0400 Subject: ./move.sh --- src/libshared/dns-domain.c | 1322 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1322 insertions(+) create mode 100644 src/libshared/dns-domain.c (limited to 'src/libshared/dns-domain.c') diff --git a/src/libshared/dns-domain.c b/src/libshared/dns-domain.c new file mode 100644 index 0000000000..45d24c0079 --- /dev/null +++ b/src/libshared/dns-domain.c @@ -0,0 +1,1322 @@ +/*** + This file is part of systemd. + + Copyright 2014 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see . + ***/ + +#ifdef HAVE_LIBIDN +#include +#include +#endif + +#include +#include +#include +#include +#include + +#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; + char *d; + int r = 0; + + assert(name); + assert(*name); + + n = *name; + d = dest; + + for (;;) { + if (*n == '.') { + n++; + break; + } + + if (*n == 0) + break; + + if (r >= DNS_LABEL_MAX) + return -EINVAL; + + if (sz <= 0) + return -ENOBUFS; + + if (*n == '\\') { + /* Escaped character */ + + n++; + + if (*n == 0) + /* Ending NUL */ + return -EINVAL; + + else if (*n == '\\' || *n == '.') { + /* Escaped backslash or dot */ + + if (d) + *(d++) = *n; + sz--; + r++; + n++; + + } else if (n[0] >= '0' && n[0] <= '9') { + unsigned k; + + /* Escaped literal ASCII character */ + + if (!(n[1] >= '0' && n[1] <= '9') || + !(n[2] >= '0' && n[2] <= '9')) + return -EINVAL; + + k = ((unsigned) (n[0] - '0') * 100) + + ((unsigned) (n[1] - '0') * 10) + + ((unsigned) (n[2] - '0')); + + /* 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; + + if (d) + *(d++) = (char) k; + sz--; + r++; + + n += 3; + } else + return -EINVAL; + + } else if ((uint8_t) *n >= (uint8_t) ' ' && *n != 127) { + + /* Normal character */ + + if (d) + *(d++) = *n; + sz--; + r++; + n++; + } else + return -EINVAL; + } + + /* Empty label that is not at the end? */ + if (r == 0 && *n) + return -EINVAL; + + if (sz >= 1 && d) + *d = 0; + + *name = n; + return r; +} + +/* @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(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; +} + +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; + + assert(p); + assert(dest); + + 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') || + (*p >= 'a' && *p <= 'z') || + (*p >= 'A' && *p <= 'Z')) { + + /* Proper character */ + + if (sz < 2) + return -ENOBUFS; + + *(q++) = *p; + 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); + + 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; + s = NULL; + + return r; +} + +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, l; + const char *p; + bool contains_8bit = false; + char buffer[DNS_LABEL_MAX+1]; + + assert(encoded); + assert(decoded); + + /* Converts an U-label into an A-label */ + + if (encoded_size <= 0) + return -EINVAL; + + for (p = encoded; p < encoded + encoded_size; p++) + if ((uint8_t) *p > 127) + contains_8bit = true; + + 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, buffer, 0) != 0) + return -EINVAL; + + l = strlen(buffer); + + /* Verify that the the result is not longer than one DNS label. */ + if (l <= 0 || l > DNS_LABEL_MAX) + return -EINVAL; + if (l > decoded_max) + return -ENOBUFS; + + 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 +} + +int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max) { +#ifdef HAVE_LIBIDN + size_t input_size, output_size; + _cleanup_free_ uint32_t *input = NULL; + _cleanup_free_ char *result = NULL; + uint32_t *output = NULL; + size_t w; + + /* 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; + + if (memcmp(encoded, IDNA_ACE_PREFIX, sizeof(IDNA_ACE_PREFIX) -1) != 0) + return 0; + + input = stringprep_utf8_to_ucs4(encoded, encoded_size, &input_size); + if (!input) + return -ENOMEM; + + output_size = input_size; + output = newa(uint32_t, output_size); + + idna_to_unicode_44i(input, input_size, output, &output_size, 0); + + result = stringprep_ucs4_to_utf8(output, output_size, NULL, &w); + if (!result) + return -ENOMEM; + if (w <= 0) + 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; + + return w; +#else + return 0; +#endif +} + +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; + bool first = true; + int r; + + if (a) + p = a; + else if (b) { + p = b; + b = NULL; + } else + goto finish; + + for (;;) { + char label[DNS_LABEL_MAX]; + + r = dns_label_unescape(&p, label, sizeof(label)); + if (r < 0) + return r; + 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; + } + + if (_ret) { + if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX)) + return -ENOMEM; + + r = dns_label_escape(label, r, ret + n + !first, DNS_LABEL_ESCAPED_MAX); + if (r < 0) + return r; + + 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) + n++; + else + first = false; + + n += r; + } + +finish: + if (n > DNS_HOSTNAME_MAX) + return -EINVAL; + + 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++] = '.'; + } else { + if (!GREEDY_REALLOC(ret, allocated, n + 1)) + return -ENOMEM; + } + + ret[n] = 0; + *_ret = ret; + ret = NULL; + } + + return 0; +} + +void dns_name_hash_func(const void *s, struct siphash *state) { + const char *p = s; + int r; + + assert(p); + + for (;;) { + char label[DNS_LABEL_MAX+1]; + + r = dns_label_unescape(&p, label, sizeof(label)); + if (r < 0) + break; + if (r == 0) + break; + + 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 */ + } + + /* 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, *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], lb[DNS_LABEL_MAX]; + + if (x == NULL && y == NULL) + return 0; + + 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; + + r = ascii_strcasecmp_nn(la, r, lb, q); + if (r != 0) + return r; + } +} + +const struct hash_ops dns_name_hash_ops = { + .hash = dns_name_hash_func, + .compare = dns_name_compare_func +}; + +int dns_name_equal(const char *x, const char *y) { + int r, q; + + assert(x); + assert(y); + + for (;;) { + char la[DNS_LABEL_MAX], lb[DNS_LABEL_MAX]; + + r = dns_label_unescape(&x, la, sizeof(la)); + if (r < 0) + return r; + + q = dns_label_unescape(&y, lb, sizeof(lb)); + if (q < 0) + return q; + + 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; + + assert(name); + assert(suffix); + + n = name; + s = suffix; + + for (;;) { + char ln[DNS_LABEL_MAX], ls[DNS_LABEL_MAX]; + + r = dns_label_unescape(&n, ln, sizeof(ln)); + if (r < 0) + return r; + + if (!saved_n) + saved_n = n; + + q = dns_label_unescape(&s, ls, sizeof(ls)); + if (q < 0) + return q; + + if (r == 0 && q == 0) + return true; + if (r == 0 && saved_n == n) + return false; + + 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; + n = saved_n; + saved_n = NULL; + } + } +} + +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; + + assert(a); + assert(ret); + + p = (const uint8_t*) a; + + if (family == AF_INET) + r = asprintf(ret, "%u.%u.%u.%u.in-addr.arpa", p[3], p[2], p[1], p[0]); + else if (family == AF_INET6) + r = asprintf(ret, "%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.ip6.arpa", + hexchar(p[15] & 0xF), hexchar(p[15] >> 4), hexchar(p[14] & 0xF), hexchar(p[14] >> 4), + hexchar(p[13] & 0xF), hexchar(p[13] >> 4), hexchar(p[12] & 0xF), hexchar(p[12] >> 4), + hexchar(p[11] & 0xF), hexchar(p[11] >> 4), hexchar(p[10] & 0xF), hexchar(p[10] >> 4), + hexchar(p[ 9] & 0xF), hexchar(p[ 9] >> 4), hexchar(p[ 8] & 0xF), hexchar(p[ 8] >> 4), + hexchar(p[ 7] & 0xF), hexchar(p[ 7] >> 4), hexchar(p[ 6] & 0xF), hexchar(p[ 6] >> 4), + hexchar(p[ 5] & 0xF), hexchar(p[ 5] >> 4), hexchar(p[ 4] & 0xF), hexchar(p[ 4] >> 4), + hexchar(p[ 3] & 0xF), hexchar(p[ 3] >> 4), hexchar(p[ 2] & 0xF), hexchar(p[ 2] >> 4), + hexchar(p[ 1] & 0xF), hexchar(p[ 1] >> 4), hexchar(p[ 0] & 0xF), hexchar(p[ 0] >> 4)); + else + return -EAFNOSUPPORT; + if (r < 0) + return -ENOMEM; + + return 0; +} + +int dns_name_address(const char *p, int *family, union in_addr_union *address) { + int r; + + assert(p); + assert(family); + assert(address); + + r = dns_name_endswith(p, "in-addr.arpa"); + if (r < 0) + return r; + if (r > 0) { + uint8_t a[4]; + unsigned i; + + for (i = 0; i < ELEMENTSOF(a); i++) { + char label[DNS_LABEL_MAX+1]; + + r = dns_label_unescape(&p, label, sizeof(label)); + if (r < 0) + return r; + if (r == 0) + return -EINVAL; + if (r > 3) + return -EINVAL; + + r = safe_atou8(label, &a[i]); + if (r < 0) + return r; + } + + r = dns_name_equal(p, "in-addr.arpa"); + if (r <= 0) + return r; + + *family = AF_INET; + address->in.s_addr = htobe32(((uint32_t) a[3] << 24) | + ((uint32_t) a[2] << 16) | + ((uint32_t) a[1] << 8) | + (uint32_t) a[0]); + + return 1; + } + + r = dns_name_endswith(p, "ip6.arpa"); + if (r < 0) + return r; + if (r > 0) { + struct in6_addr a; + unsigned i; + + for (i = 0; i < ELEMENTSOF(a.s6_addr); i++) { + char label[DNS_LABEL_MAX+1]; + int x, y; + + r = dns_label_unescape(&p, label, sizeof(label)); + if (r <= 0) + return r; + if (r != 1) + return -EINVAL; + x = unhexchar(label[0]); + if (x < 0) + return -EINVAL; + + r = dns_label_unescape(&p, label, sizeof(label)); + if (r <= 0) + return r; + if (r != 1) + return -EINVAL; + y = unhexchar(label[0]); + if (y < 0) + return -EINVAL; + + a.s6_addr[ELEMENTSOF(a.s6_addr) - i - 1] = (uint8_t) y << 4 | (uint8_t) x; + } + + r = dns_name_equal(p, "ip6.arpa"); + if (r <= 0) + return r; + + *family = AF_INET6; + address->in6 = a; + return 1; + } + + return 0; +} + +bool dns_name_is_root(const char *name) { + + assert(name); + + /* There are exactly two ways to encode the root domain name: + * as empty string, or with a single dot. */ + + return STR_IN_SET(name, "", "."); +} + +bool dns_name_is_single_label(const char *name) { + int r; + + assert(name); + + 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; + + 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 = 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 . . */ + + 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; + + 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; +} -- cgit v1.2.3-54-g00ecf