diff options
Diffstat (limited to 'src/shared/dns-domain.c')
-rw-r--r-- | src/shared/dns-domain.c | 406 |
1 files changed, 277 insertions, 129 deletions
diff --git a/src/shared/dns-domain.c b/src/shared/dns-domain.c index c46f7d21b7..3ad409fc29 100644 --- a/src/shared/dns-domain.c +++ b/src/shared/dns-domain.c @@ -98,8 +98,13 @@ 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; if (d) @@ -154,20 +159,24 @@ int dns_label_unescape_suffix(const char *name, const char **label_terminal, cha return 0; } - assert(**label_terminal == '.' || **label_terminal == 0); + terminal = *label_terminal; + assert(*terminal == '.' || *terminal == 0); - /* skip current terminal character */ - terminal = *label_terminal - 1; + /* 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) */ + /* 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 */ + /* Reached the first label, so indicate that there are no more */ terminal = NULL; break; } - /* find the start of the last label */ + /* Find the start of the last label */ if (*terminal == '.') { const char *y; unsigned slashes = 0; @@ -176,7 +185,7 @@ int dns_label_unescape_suffix(const char *name, const char **label_terminal, cha slashes ++; if (slashes % 2 == 0) { - /* the '.' was not escaped */ + /* The '.' was not escaped */ name = terminal + 1; break; } else { @@ -241,7 +250,7 @@ int dns_label_escape(const char *p, size_t l, char *dest, size_t sz) { *(q++) = *p; sz -= 1; - } else if ((uint8_t) *p >= (uint8_t) ' ' && *p != 127) { + } else { /* Everything else */ @@ -254,9 +263,7 @@ int dns_label_escape(const char *p, size_t l, char *dest, size_t sz) { *(q++) = '0' + (char) ((uint8_t) *p % 10); sz -= 4; - - } else - return -EINVAL; + } p++; l--; @@ -406,7 +413,6 @@ int dns_name_concat(const char *a, const char *b, char **_ret) { for (;;) { char label[DNS_LABEL_MAX]; - int k; r = dns_label_unescape(&p, label, sizeof(label)); if (r < 0) @@ -425,12 +431,6 @@ int dns_name_concat(const char *a, const char *b, char **_ret) { 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; @@ -478,27 +478,18 @@ void dns_name_hash_func(const void *s, struct siphash *state) { 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) - break; - if (k > 0) - r = k; - if (r == 0) break; - label[r] = 0; - ascii_strlower(label); - - string_hash_func(label, state); + 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 */ @@ -507,7 +498,7 @@ void dns_name_hash_func(const void *s, struct siphash *state) { int dns_name_compare_func(const void *a, const void *b) { const char *x, *y; - int r, q, k, w; + int r, q; assert(a); assert(b); @@ -516,7 +507,7 @@ int dns_name_compare_func(const void *a, const void *b) { 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 == NULL && y == NULL) return 0; @@ -526,17 +517,7 @@ int dns_name_compare_func(const void *a, const void *b) { 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; } @@ -548,53 +529,35 @@ 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; - if (r > 0) { - 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; - if (q > 0) { - w = dns_label_undo_idna(lb, q, lb, sizeof(lb)); - if (w < 0) - return w; - if (w > 0) - q = w; - } - /* If one name had fewer labels than the other, this - * will show up as empty label here, which the - * strcasecmp() below will properly consider different - * from a non-empty label. */ + if (r != q) + return false; + if (r == 0) + return true; - la[r] = lb[q] = 0; - if (strcasecmp(la, lb) != 0) + 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); @@ -603,18 +566,11 @@ 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; - if (r > 0) { - 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; @@ -622,22 +578,13 @@ int dns_name_endswith(const char *name, const char *suffix) { q = dns_label_unescape(&s, ls, sizeof(ls)); if (q < 0) return q; - if (q > 0) { - 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; @@ -647,9 +594,39 @@ 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, k, w; + int r, q; assert(name); assert(old_suffix); @@ -660,7 +637,7 @@ int dns_name_change_suffix(const char *name, const char *old_suffix, const char s = old_suffix; for (;;) { - char ln[DNS_LABEL_MAX+1], ls[DNS_LABEL_MAX+1]; + char ln[DNS_LABEL_MAX], ls[DNS_LABEL_MAX]; if (!saved_before) saved_before = n; @@ -668,13 +645,6 @@ int dns_name_change_suffix(const char *name, const char *old_suffix, const char r = dns_label_unescape(&n, ln, sizeof(ln)); if (r < 0) return r; - if (r > 0) { - k = dns_label_undo_idna(ln, r, ln, sizeof(ln)); - if (k < 0) - return k; - if (k > 0) - r = k; - } if (!saved_after) saved_after = n; @@ -682,13 +652,6 @@ int dns_name_change_suffix(const char *name, const char *old_suffix, const char q = dns_label_unescape(&s, ls, sizeof(ls)); if (q < 0) return q; - if (q > 0) { - 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) break; @@ -697,9 +660,7 @@ int dns_name_change_suffix(const char *name, const char *old_suffix, const char return 0; } - 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 = old_suffix; @@ -867,12 +828,11 @@ bool dns_name_is_root(const char *name) { } bool dns_name_is_single_label(const char *name) { - char label[DNS_LABEL_MAX+1]; int r; assert(name); - r = dns_label_unescape(&name, label, sizeof(label)); + r = dns_name_parent(&name); if (r <= 0) return false; @@ -905,19 +865,11 @@ int dns_name_to_wire_format(const char *domain, uint8_t *buffer, size_t len, boo if (r < 0) return r; - if (canonical) { - size_t i; - - /* Optionally, output the name in DNSSEC - * canonical format, as described in RFC 4034, - * section 6.2. Or in other words: in - * lower-case. */ - - for (i = 0; i < (size_t) r; i++) { - if (out[i] >= 'A' && out[i] <= 'Z') - out[i] = out[i] - 'A' + 'a'; - } - } + /* 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; @@ -1101,17 +1053,15 @@ int dns_service_split(const char *joined, char **_name, char **_type, char **_do 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 = new(char, bn+1+cn+1); + type = strjoin(b, ".", c, NULL); if (!type) return -ENOMEM; - strcpy(stpcpy(stpcpy(type, b), "."), c); d = p; goto finish; @@ -1123,10 +1073,9 @@ int dns_service_split(const char *joined, char **_name, char **_type, char **_do name = NULL; - type = new(char, an+1+bn+1); + type = strjoin(a, ".", b, NULL); if (!type) return -ENOMEM; - strcpy(stpcpy(stpcpy(type, a), "."), b); d = q; goto finish; @@ -1159,3 +1108,202 @@ finish: 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; +} |