On 09/08/2010 10:15 AM, shirishpargaonkar@xxxxxxxxx wrote:
> From: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
>
>
> Allocate crypto hashing functions, ecurity descriptiors, and respective
> contexts when a smb/tcp connection is established.
> Release them when a tcp/smb connection is taken down.
>
> md5 and hmac-md5 are two crypto hashing functions that are used
> throught the life of an smb/tcp connection by various functions that
> calcualte signagure and ntlmv2 hash, HMAC etc.
>
>
> Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
> ---
> fs/cifs/cifsencrypt.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++
> fs/cifs/cifsproto.h | 2 +
> fs/cifs/connect.c | 16 +++++++++--
> 3 files changed, 86 insertions(+), 3 deletions(-)
>
> diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
> index 4bdcf13..4772c4d 100644
> --- a/fs/cifs/cifsencrypt.c
> +++ b/fs/cifs/cifsencrypt.c
> @@ -369,3 +369,74 @@ void CalcNTLMv2_response(const struct cifsSesInfo *ses,
> hmac_md5_final(v2_session_response, &context);
> /* cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); */
> }
> +
> +void
> +cifs_crypto_shash_release(struct TCP_Server_Info *server)
> +{
> + if (server->secmech.md5)
> + crypto_free_shash(server->secmech.md5);
> +
> + if (server->secmech.hmacmd5)
> + crypto_free_shash(server->secmech.hmacmd5);
> +
> + kfree(server->secmech.sdeschmacmd5);
> +
> + kfree(server->secmech.sdescmd5);
> +}
> +
> +int
> +cifs_crypto_shash_allocate(struct TCP_Server_Info *server)
> +{
> + int rc;
> + unsigned int size;
> +
> + server->secmech.hmacmd5 = crypto_alloc_shash("hmac(md5)", 0, 0);
> + if (!server->secmech.hmacmd5 ||
> + IS_ERR(server->secmech.hmacmd5)) {
crypto_alloc_hash() seems to return a pointer to struct crypto_shash.
Would it be sufficient to use IS_ERR() to check?
Also, instead of returning 1, we should use PTR_ERR() to propagate the
appropriate error back. Otherwise, rc will always be 1 which gives
little clue in case of error..
> + cERROR(1, "could not allocate crypto hmacmd5\n");
> + return 1;
> + }
> +
> + server->secmech.md5 = crypto_alloc_shash("md5", 0, 0);
> + if (!server->secmech.md5 || IS_ERR(server->secmech.md5)) {
> + cERROR(1, "could not allocate crypto md5\n");
> + rc = 1;
ditto here..
> + goto cifs_crypto_shash_allocate_ret1;
nit: the goto labels could use better names..?
> + }
> +
> + size = sizeof(struct shash_desc) +
> + crypto_shash_descsize(server->secmech.hmacmd5);
> + server->secmech.sdeschmacmd5 = kmalloc(size, GFP_KERNEL);
> + if (!server->secmech.sdeschmacmd5) {
> + cERROR(1, "cifs_crypto_shash_allocate: can't alloc hmacmd5\n");
> + rc = -ENOMEM;
> + goto cifs_crypto_shash_allocate_ret2;
> + }
> + server->secmech.sdeschmacmd5->shash.tfm = server->secmech.hmacmd5;
> + server->secmech.sdeschmacmd5->shash.flags = 0x0;
> +
> +
> + size = sizeof(struct shash_desc) +
> + crypto_shash_descsize(server->secmech.md5);
> + server->secmech.sdescmd5 = kmalloc(size, GFP_KERNEL);
> + if (!server->secmech.sdescmd5) {
> + cERROR(1, "cifs_crypto_shash_allocate: can't alloc md5\n");
> + rc = -ENOMEM;
> + goto cifs_crypto_shash_allocate_ret3;
> + }
> + server->secmech.sdescmd5->shash.tfm = server->secmech.md5;
> + server->secmech.sdescmd5->shash.flags = 0x0;
> +
> + return 0;
> +
> +cifs_crypto_shash_allocate_ret3:
> + kfree(server->secmech.sdeschmacmd5);
> +
> +cifs_crypto_shash_allocate_ret2:
> + crypto_free_shash(server->secmech.md5);
> +
> +cifs_crypto_shash_allocate_ret1:
> + crypto_free_shash(server->secmech.hmacmd5);
> +
> + return rc;
> +}
> diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
> index eadf78c..fa3716c 100644
> --- a/fs/cifs/cifsproto.h
> +++ b/fs/cifs/cifsproto.h
> @@ -368,6 +368,8 @@ extern int cifs_calculate_mac_key(struct session_key *key, const char *rn,
> extern void CalcNTLMv2_response(const struct cifsSesInfo *, char *);
> extern void setup_ntlmv2_rsp(struct cifsSesInfo *, char *,
> const struct nls_table *);
> +extern int cifs_crypto_shash_allocate(struct TCP_Server_Info *);
> +extern void cifs_crypto_shash_release(struct TCP_Server_Info *);
> #ifdef CONFIG_CIFS_WEAK_PW_HASH
> extern void calc_lanman_hash(const char *password, const char *cryptkey,
> bool encrypt, char *lnm_session_key);
> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> index 0ea52e9..f5369e7 100644
> --- a/fs/cifs/connect.c
> +++ b/fs/cifs/connect.c
> @@ -1520,6 +1520,7 @@ cifs_put_tcp_session(struct TCP_Server_Info *server)
> server->tcpStatus = CifsExiting;
> spin_unlock(&GlobalMid_Lock);
>
> + cifs_crypto_shash_release(server);
> cifs_fscache_release_client_cookie(server);
>
> task = xchg(&server->tsk, NULL);
> @@ -1574,10 +1575,16 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
> goto out_err;
> }
>
> + rc = cifs_crypto_shash_allocate(tcp_ses);
> + if (rc) {
> + cERROR(1, "could not setup hash structures rc %d", rc);
> + goto out_err;
> + }
> +
> tcp_ses->hostname = extract_hostname(volume_info->UNC);
> if (IS_ERR(tcp_ses->hostname)) {
> rc = PTR_ERR(tcp_ses->hostname);
> - goto out_err;
> + goto out_err2;
> }
>
> tcp_ses->noblocksnd = volume_info->noblocksnd;
> @@ -1618,7 +1625,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
> }
> if (rc < 0) {
> cERROR(1, "Error connecting to socket. Aborting operation");
> - goto out_err;
> + goto out_err2;
> }
>
> /*
> @@ -1632,7 +1639,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
> rc = PTR_ERR(tcp_ses->tsk);
> cERROR(1, "error %d create cifsd thread", rc);
> module_put(THIS_MODULE);
> - goto out_err;
> + goto out_err2;
> }
>
> /* thread spawned, put it on the list */
> @@ -1644,6 +1651,9 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
>
> return tcp_ses;
>
> +out_err2:
> + cifs_crypto_shash_release(tcp_ses);
> +
> out_err:
> if (tcp_ses) {
> if (!IS_ERR(tcp_ses->hostname))
--
Suresh Jayaraman
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