From 8a8798a5ff90977d6459ce1d657cf8fe13a51e97 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 17 Jan 2012 16:09:15 -0500 Subject: [PATCH] cifs: fetch credentials out of keyring for non-krb5 auth multiuser mounts Fix up multiuser mounts to set the secType and set the username and password from the key payload in the vol info for non-krb5 auth types. Look for a key of type "secret" with a description of "cifs:a:" or "cifs:d:". If that's found, then scrape the username and password out of the key payload and use that to create a new user session. Finally, don't have the code enforce krb5 auth on multiuser mounts, but do require a kernel with keys support. Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/connect.c | 175 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 165 insertions(+), 10 deletions(-) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index b952a21e917b..28f23c03da53 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -38,6 +38,7 @@ #include #include #include +#include #include #include "cifspdu.h" #include "cifsglob.h" @@ -1594,11 +1595,14 @@ cifs_parse_mount_options(const char *mountdata, const char *devname, } } - if (vol->multiuser && !(vol->secFlg & CIFSSEC_MAY_KRB5)) { - cERROR(1, "Multiuser mounts currently require krb5 " - "authentication!"); +#ifndef CONFIG_KEYS + /* Muliuser mounts require CONFIG_KEYS support */ + if (vol->multiuser) { + cERROR(1, "Multiuser mounts require kernels with " + "CONFIG_KEYS enabled."); goto cifs_parse_mount_err; } +#endif if (vol->UNCip == NULL) vol->UNCip = &vol->UNC[2]; @@ -2061,6 +2065,132 @@ cifs_put_smb_ses(struct cifs_ses *ses) cifs_put_tcp_session(server); } +#ifdef CONFIG_KEYS + +/* strlen("cifs:a:") + INET6_ADDRSTRLEN + 1 */ +#define CIFSCREDS_DESC_SIZE (7 + INET6_ADDRSTRLEN + 1) + +/* Populate username and pw fields from keyring if possible */ +static int +cifs_set_cifscreds(struct smb_vol *vol, struct cifs_ses *ses) +{ + int rc = 0; + char *desc, *delim, *payload; + ssize_t len; + struct key *key; + struct TCP_Server_Info *server = ses->server; + struct sockaddr_in *sa; + struct sockaddr_in6 *sa6; + struct user_key_payload *upayload; + + desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL); + if (!desc) + return -ENOMEM; + + /* try to find an address key first */ + switch (server->dstaddr.ss_family) { + case AF_INET: + sa = (struct sockaddr_in *)&server->dstaddr; + sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr); + break; + case AF_INET6: + sa6 = (struct sockaddr_in6 *)&server->dstaddr; + sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr); + break; + default: + cFYI(1, "Bad ss_family (%hu)", server->dstaddr.ss_family); + rc = -EINVAL; + goto out_err; + } + + cFYI(1, "%s: desc=%s", __func__, desc); + key = request_key(&key_type_logon, desc, ""); + if (IS_ERR(key)) { + if (!ses->domainName) { + cFYI(1, "domainName is NULL"); + rc = PTR_ERR(key); + goto out_err; + } + + /* didn't work, try to find a domain key */ + sprintf(desc, "cifs:d:%s", ses->domainName); + cFYI(1, "%s: desc=%s", __func__, desc); + key = request_key(&key_type_logon, desc, ""); + if (IS_ERR(key)) { + rc = PTR_ERR(key); + goto out_err; + } + } + + down_read(&key->sem); + upayload = key->payload.data; + if (IS_ERR_OR_NULL(upayload)) { + rc = PTR_ERR(key); + goto out_key_put; + } + + /* find first : in payload */ + payload = (char *)upayload->data; + delim = strnchr(payload, upayload->datalen, ':'); + cFYI(1, "payload=%s", payload); + if (!delim) { + cFYI(1, "Unable to find ':' in payload (datalen=%d)", + upayload->datalen); + rc = -EINVAL; + goto out_key_put; + } + + len = delim - payload; + if (len > MAX_USERNAME_SIZE || len <= 0) { + cFYI(1, "Bad value from username search (len=%ld)", len); + rc = -EINVAL; + goto out_key_put; + } + + vol->username = kstrndup(payload, len, GFP_KERNEL); + if (!vol->username) { + cFYI(1, "Unable to allocate %ld bytes for username", len); + rc = -ENOMEM; + goto out_key_put; + } + cFYI(1, "%s: username=%s", __func__, vol->username); + + len = key->datalen - (len + 1); + if (len > MAX_PASSWORD_SIZE || len <= 0) { + cFYI(1, "Bad len for password search (len=%ld)", len); + rc = -EINVAL; + kfree(vol->username); + vol->username = NULL; + goto out_key_put; + } + + ++delim; + vol->password = kstrndup(delim, len, GFP_KERNEL); + if (!vol->password) { + cFYI(1, "Unable to allocate %ld bytes for password", len); + rc = -ENOMEM; + kfree(vol->username); + vol->username = NULL; + goto out_key_put; + } + +out_key_put: + up_read(&key->sem); + key_put(key); +out_err: + kfree(desc); + cFYI(1, "%s: returning %d", __func__, rc); + return rc; +} +#else /* ! CONFIG_KEYS */ +static inline int +cifs_set_cifscreds(struct smb_vol *vol __attribute__((unused)), + struct cifs_ses *ses __attribute__((unused))) +{ + return -ENOSYS; +} +#endif /* CONFIG_KEYS */ + static bool warned_on_ntlm; /* globals init to false automatically */ static struct cifs_ses * @@ -3693,16 +3823,38 @@ int cifs_setup_session(unsigned int xid, struct cifs_ses *ses, return rc; } +static int +cifs_set_vol_auth(struct smb_vol *vol, struct cifs_ses *ses) +{ + switch (ses->server->secType) { + case Kerberos: + vol->secFlg = CIFSSEC_MUST_KRB5; + return 0; + case NTLMv2: + vol->secFlg = CIFSSEC_MUST_NTLMV2; + break; + case NTLM: + vol->secFlg = CIFSSEC_MUST_NTLM; + break; + case RawNTLMSSP: + vol->secFlg = CIFSSEC_MUST_NTLMSSP; + break; + case LANMAN: + vol->secFlg = CIFSSEC_MUST_LANMAN; + break; + } + + return cifs_set_cifscreds(vol, ses); +} + static struct cifs_tcon * cifs_construct_tcon(struct cifs_sb_info *cifs_sb, uid_t fsuid) { + int rc; struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb); struct cifs_ses *ses; struct cifs_tcon *tcon = NULL; struct smb_vol *vol_info; - char username[28]; /* big enough for "krb50x" + hex of ULONG_MAX 6+16 */ - /* We used to have this as MAX_USERNAME which is */ - /* way too big now (256 instead of 32) */ vol_info = kzalloc(sizeof(*vol_info), GFP_KERNEL); if (vol_info == NULL) { @@ -3710,8 +3862,6 @@ cifs_construct_tcon(struct cifs_sb_info *cifs_sb, uid_t fsuid) goto out; } - snprintf(username, sizeof(username), "krb50x%x", fsuid); - vol_info->username = username; vol_info->local_nls = cifs_sb->local_nls; vol_info->linux_uid = fsuid; vol_info->cred_uid = fsuid; @@ -3721,8 +3871,11 @@ cifs_construct_tcon(struct cifs_sb_info *cifs_sb, uid_t fsuid) vol_info->local_lease = master_tcon->local_lease; vol_info->no_linux_ext = !master_tcon->unix_ext; - /* FIXME: allow for other secFlg settings */ - vol_info->secFlg = CIFSSEC_MUST_KRB5; + rc = cifs_set_vol_auth(vol_info, master_tcon->ses); + if (rc) { + tcon = ERR_PTR(rc); + goto out; + } /* get a reference for the same TCP session */ spin_lock(&cifs_tcp_ses_lock); @@ -3745,6 +3898,8 @@ cifs_construct_tcon(struct cifs_sb_info *cifs_sb, uid_t fsuid) if (ses->capabilities & CAP_UNIX) reset_cifs_unix_caps(0, tcon, NULL, vol_info); out: + kfree(vol_info->username); + kfree(vol_info->password); kfree(vol_info); return tcon; -- GitLab