diff options
| -rw-r--r-- | fs/cifs/dns_resolve.c | 62 |
1 files changed, 52 insertions, 10 deletions
diff --git a/fs/cifs/dns_resolve.c b/fs/cifs/dns_resolve.c index 7cc86c41818..939e256f849 100644 --- a/fs/cifs/dns_resolve.c +++ b/fs/cifs/dns_resolve.c @@ -55,6 +55,32 @@ struct key_type key_type_dns_resolver = { .match = user_match, }; +/* Checks if supplied name is IP address + * returns: + * 1 - name is IP + * 0 - name is not IP + */ +static int is_ip(const char *name) +{ + int rc; + struct sockaddr_in sin_server; + struct sockaddr_in6 sin_server6; + + rc = cifs_inet_pton(AF_INET, name, + &sin_server.sin_addr.s_addr); + + if (rc <= 0) { + /* not ipv4 address, try ipv6 */ + rc = cifs_inet_pton(AF_INET6, name, + &sin_server6.sin6_addr.in6_u); + if (rc > 0) + return 1; + } else { + return 1; + } + /* we failed translating address */ + return 0; +} /* Resolves server name to ip address. * input: @@ -67,8 +93,9 @@ int dns_resolve_server_name_to_ip(const char *unc, char **ip_addr) { int rc = -EAGAIN; - struct key *rkey; + struct key *rkey = ERR_PTR(-EAGAIN); char *name; + char *data = NULL; int len; if (!ip_addr || !unc) @@ -97,26 +124,41 @@ dns_resolve_server_name_to_ip(const char *unc, char **ip_addr) memcpy(name, unc+2, len); name[len] = 0; + if (is_ip(name)) { + cFYI(1, ("%s: it is IP, skipping dns upcall: %s", + __func__, name)); + data = name; + goto skip_upcall; + } + rkey = request_key(&key_type_dns_resolver, name, ""); if (!IS_ERR(rkey)) { - len = strlen(rkey->payload.data); - *ip_addr = kmalloc(len+1, GFP_KERNEL); - if (*ip_addr) { - memcpy(*ip_addr, rkey->payload.data, len); - (*ip_addr)[len] = '\0'; - cFYI(1, ("%s: resolved: %s to %s", __func__, + data = rkey->payload.data; + cFYI(1, ("%s: resolved: %s to %s", __func__, rkey->description, *ip_addr )); + } else { + cERROR(1, ("%s: unable to resolve: %s", __func__, name)); + goto out; + } + +skip_upcall: + if (data) { + len = strlen(data); + *ip_addr = kmalloc(len+1, GFP_KERNEL); + if (*ip_addr) { + memcpy(*ip_addr, data, len); + (*ip_addr)[len] = '\0'; rc = 0; } else { rc = -ENOMEM; } - key_put(rkey); - } else { - cERROR(1, ("%s: unable to resolve: %s", __func__, name)); + if (!IS_ERR(rkey)) + key_put(rkey); } +out: kfree(name); return rc; } |