From 9d81523480c8c5b07a4899a084b3f4264a575184 Mon Sep 17 00:00:00 2001 From: Steve French Date: Tue, 23 Sep 2008 18:46:07 +0000 Subject: [CIFS] clean up upcall handling for dns_resolver keys We're given the datalen in the downcall, so there's no need to do any calls to strlen(). Just keep track of the datalen in the key. Finally, add a sanity check of the data in the downcall to make sure that it looks like a real IP address. Signed-off-by: Jeff Layton Acked-by: David Howells Signed-off-by: Steve French --- fs/cifs/dns_resolve.c | 74 ++++++++++++++++++++++++++++----------------------- 1 file changed, 41 insertions(+), 33 deletions(-) (limited to 'fs/cifs/dns_resolve.c') diff --git a/fs/cifs/dns_resolve.c b/fs/cifs/dns_resolve.c index a2e0673e1b08..1e0c1bd8f2e4 100644 --- a/fs/cifs/dns_resolve.c +++ b/fs/cifs/dns_resolve.c @@ -29,19 +29,55 @@ #include "cifsproto.h" #include "cifs_debug.h" -static int dns_resolver_instantiate(struct key *key, const void *data, +/* 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; +} + +static int +dns_resolver_instantiate(struct key *key, const void *data, size_t datalen) { int rc = 0; char *ip; - ip = kmalloc(datalen+1, GFP_KERNEL); + ip = kmalloc(datalen + 1, GFP_KERNEL); if (!ip) return -ENOMEM; memcpy(ip, data, datalen); ip[datalen] = '\0'; + /* make sure this looks like an address */ + if (!is_ip((const char *) ip)) { + kfree(ip); + return -EINVAL; + } + + key->type_data.x[0] = datalen; rcu_assign_pointer(key->payload.data, ip); return rc; @@ -62,33 +98,6 @@ 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: * unc - server UNC @@ -140,6 +149,7 @@ dns_resolve_server_name_to_ip(const char *unc, char **ip_addr) rkey = request_key(&key_type_dns_resolver, name, ""); if (!IS_ERR(rkey)) { + len = rkey->type_data.x[0]; data = rkey->payload.data; } else { cERROR(1, ("%s: unable to resolve: %s", __func__, name)); @@ -148,11 +158,9 @@ dns_resolve_server_name_to_ip(const char *unc, char **ip_addr) skip_upcall: if (data) { - len = strlen(data); - *ip_addr = kmalloc(len+1, GFP_KERNEL); + *ip_addr = kmalloc(len + 1, GFP_KERNEL); if (*ip_addr) { - memcpy(*ip_addr, data, len); - (*ip_addr)[len] = '\0'; + memcpy(*ip_addr, data, len + 1); if (!IS_ERR(rkey)) cFYI(1, ("%s: resolved: %s to %s", __func__, name, -- cgit v1.2.3-59-g8ed1b