diff options
Diffstat (limited to 'src/shared/dns-domain.c')
| -rw-r--r-- | src/shared/dns-domain.c | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/src/shared/dns-domain.c b/src/shared/dns-domain.c index 3ad409fc29..7ef4ad3cf8 100644 --- a/src/shared/dns-domain.c +++ b/src/shared/dns-domain.c @@ -405,11 +405,17 @@ int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded, 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 = a; + const char *p; bool first = true; int r; - assert(a); + if (a) + p = a; + else if (b) { + p = b; + b = NULL; + } else + goto finish; for (;;) { char label[DNS_LABEL_MAX]; @@ -457,12 +463,21 @@ int dns_name_concat(const char *a, const char *b, char **_ret) { n += r; } +finish: if (n > DNS_HOSTNAME_MAX) return -EINVAL; if (_ret) { - if (!GREEDY_REALLOC(ret, allocated, n + 1)) - return -ENOMEM; + 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; |