Commit d7f1affc authored by Dmitry Antipov's avatar Dmitry Antipov Committed by Steve French
Browse files

cifs: avoid extra calls to strlen() in cifs_get_spnego_key() 



Since 'snprintf()' returns the number of characters emitted, an
output position may be advanced with this return value rather
than using an explicit calls to 'strlen()'. Compile tested only.

Signed-off-by: default avatarDmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent b63335fb

fs/smb/client/cifs_spnego.c

+18 −29
Original line number Diff line number Diff line
@@ -124,55 +124,44 @@ cifs_get_spnego_key(struct cifs_ses *sesInfo, 
	dp = description;

	/* start with version and hostname portion of UNC string */

	spnego_key = ERR_PTR(-EINVAL);

	sprintf(dp, "ver=0x%x;host=%s;", CIFS_SPNEGO_UPCALL_VERSION,

	dp += sprintf(dp, "ver=0x%x;host=%s;", CIFS_SPNEGO_UPCALL_VERSION,

		      hostname);

	dp = description + strlen(description);



	/* add the server address */

	if (server->dstaddr.ss_family == AF_INET)

		sprintf(dp, "ip4=%pI4", &sa->sin_addr);

		dp += sprintf(dp, "ip4=%pI4", &sa->sin_addr);

	else if (server->dstaddr.ss_family == AF_INET6)

		sprintf(dp, "ip6=%pI6", &sa6->sin6_addr);

		dp += sprintf(dp, "ip6=%pI6", &sa6->sin6_addr);

	else

		goto out;



	dp = description + strlen(description);



	/* for now, only sec=krb5 and sec=mskrb5 and iakerb are valid */

	if (server->sec_kerberos)

		sprintf(dp, ";sec=krb5");

		dp += sprintf(dp, ";sec=krb5");

	else if (server->sec_mskerberos)

		sprintf(dp, ";sec=mskrb5");

		dp += sprintf(dp, ";sec=mskrb5");

	else if (server->sec_iakerb)

		sprintf(dp, ";sec=iakerb");

		dp += sprintf(dp, ";sec=iakerb");

	else {

		cifs_dbg(VFS, "unknown or missing server auth type, use krb5\n");

		sprintf(dp, ";sec=krb5");

		dp += sprintf(dp, ";sec=krb5");

	}



	dp = description + strlen(description);

	sprintf(dp, ";uid=0x%x",

	dp += sprintf(dp, ";uid=0x%x",

		      from_kuid_munged(&init_user_ns, sesInfo->linux_uid));



	dp = description + strlen(description);

	sprintf(dp, ";creduid=0x%x",

	dp += sprintf(dp, ";creduid=0x%x",

		from_kuid_munged(&init_user_ns, sesInfo->cred_uid));



	if (sesInfo->user_name) {

		dp = description + strlen(description);

		sprintf(dp, ";user=%s", sesInfo->user_name);

	}

	if (sesInfo->user_name)

		dp += sprintf(dp, ";user=%s", sesInfo->user_name);



	dp = description + strlen(description);

	sprintf(dp, ";pid=0x%x", current->pid);

	dp += sprintf(dp, ";pid=0x%x", current->pid);



	if (sesInfo->upcall_target == UPTARGET_MOUNT) {

		dp = description + strlen(description);

		sprintf(dp, ";upcall_target=mount");

	} else {

		dp = description + strlen(description);

		sprintf(dp, ";upcall_target=app");

	}

	if (sesInfo->upcall_target == UPTARGET_MOUNT)

		dp += sprintf(dp, ";upcall_target=mount");

	else

		dp += sprintf(dp, ";upcall_target=app");



	cifs_dbg(FYI, "key description = %s\n", description);

	saved_cred = override_creds(spnego_cred);