diff options
Diffstat (limited to 'src/shared/dns-domain.c')
| -rw-r--r-- | src/shared/dns-domain.c | 124 |
1 files changed, 106 insertions, 18 deletions
diff --git a/src/shared/dns-domain.c b/src/shared/dns-domain.c index 0466857042..68404ca9e5 100644 --- a/src/shared/dns-domain.c +++ b/src/shared/dns-domain.c @@ -48,7 +48,6 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) { assert(name); assert(*name); - assert(dest); n = *name; d = dest; @@ -79,9 +78,12 @@ 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; @@ -96,11 +98,17 @@ 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++; @@ -111,9 +119,12 @@ 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; } @@ -122,7 +133,7 @@ int dns_label_unescape(const char **name, char *dest, size_t sz) { if (r == 0 && *n) return -EINVAL; - if (sz >= 1) + if (sz >= 1 && d) *d = 0; *name = n; @@ -148,20 +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; @@ -170,7 +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 { @@ -235,7 +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 */ @@ -249,8 +264,7 @@ int dns_label_escape(const char *p, size_t l, char *dest, size_t sz) { sz -= 4; - } else - return -EINVAL; + } p++; l--; @@ -527,7 +541,7 @@ int dns_name_compare_func(const void *a, const void *b) { if (k > 0) r = k; if (w > 0) - r = w; + q = w; la[r] = lb[q] = 0; r = strcasecmp(la, lb); @@ -1153,3 +1167,77 @@ finish: return 0; } + +int dns_name_suffix(const char *name, unsigned n_labels, const char **ret) { + const char* labels[DNS_N_LABELS_MAX+1]; + unsigned n = 0; + const char *p; + int r; + + assert(name); + assert(ret); + + p = name; + for (;;) { + if (n > DNS_N_LABELS_MAX) + return -EINVAL; + + labels[n] = p; + + r = dns_name_parent(&p); + if (r < 0) + return r; + if (r == 0) + break; + + n++; + } + + if (n < n_labels) + return -EINVAL; + + *ret = labels[n - n_labels]; + return (int) (n - n_labels); +} + +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); + + while (n_labels > 0) { + + r = dns_name_parent(&a); + if (r <= 0) + return r; + + n_labels --; + } + + return dns_name_equal(a, b); +} |