From 349e13ad30b45998bb9937cfe0b32be6f951976d Mon Sep 17 00:00:00 2001 From: Aurelien Aptel Date: Sat, 8 Feb 2020 15:50:57 +0100 Subject: cifs: add smb2 POSIX info level * add new info level and structs for SMB2 posix extension * add functions to parse and validate it Signed-off-by: Aurelien Aptel Signed-off-by: Steve French --- fs/cifs/cifspdu.h | 1 + fs/cifs/smb2pdu.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/cifs/smb2pdu.h | 44 +++++++++++++++++++++++++ fs/cifs/smb2proto.h | 2 ++ 4 files changed, 142 insertions(+) (limited to 'fs') diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h index 79d842e7240c..8e15887d1f1f 100644 --- a/fs/cifs/cifspdu.h +++ b/fs/cifs/cifspdu.h @@ -1691,6 +1691,7 @@ struct smb_t2_rsp { #define SMB_FIND_FILE_ID_FULL_DIR_INFO 0x105 #define SMB_FIND_FILE_ID_BOTH_DIR_INFO 0x106 #define SMB_FIND_FILE_UNIX 0x202 +#define SMB_FIND_FILE_POSIX_INFO 0x064 typedef struct smb_com_transaction2_qpi_req { struct smb_hdr hdr; /* wct = 14+ */ diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index ab31d6f54221..08d6a130e512 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -4302,6 +4302,101 @@ SMB2_write(const unsigned int xid, struct cifs_io_parms *io_parms, return rc; } +static int posix_info_sid_size(const void *beg, const void *end) +{ + size_t subauth; + int total; + + if (beg + 1 > end) + return -1; + + subauth = *(u8 *)(beg+1); + if (subauth < 1 || subauth > 15) + return -1; + + total = 1 + 1 + 6 + 4*subauth; + if (beg + total > end) + return -1; + + return total; +} + +int posix_info_parse(const void *beg, const void *end, + struct smb2_posix_info_parsed *out) + +{ + int total_len = 0; + int sid_len; + int name_len; + const void *owner_sid; + const void *group_sid; + const void *name; + + /* if no end bound given, assume payload to be correct */ + if (!end) { + const struct smb2_posix_info *p = beg; + + end = beg + le32_to_cpu(p->NextEntryOffset); + /* last element will have a 0 offset, pick a sensible bound */ + if (end == beg) + end += 0xFFFF; + } + + /* check base buf */ + if (beg + sizeof(struct smb2_posix_info) > end) + return -1; + total_len = sizeof(struct smb2_posix_info); + + /* check owner sid */ + owner_sid = beg + total_len; + sid_len = posix_info_sid_size(owner_sid, end); + if (sid_len < 0) + return -1; + total_len += sid_len; + + /* check group sid */ + group_sid = beg + total_len; + sid_len = posix_info_sid_size(group_sid, end); + if (sid_len < 0) + return -1; + total_len += sid_len; + + /* check name len */ + if (beg + total_len + 4 > end) + return -1; + name_len = le32_to_cpu(*(__le32 *)(beg + total_len)); + if (name_len < 1 || name_len > 0xFFFF) + return -1; + total_len += 4; + + /* check name */ + name = beg + total_len; + if (name + name_len > end) + return -1; + total_len += name_len; + + if (out) { + out->base = beg; + out->size = total_len; + out->name_len = name_len; + out->name = name; + memcpy(&out->owner, owner_sid, + posix_info_sid_size(owner_sid, end)); + memcpy(&out->group, group_sid, + posix_info_sid_size(group_sid, end)); + } + return total_len; +} + +static int posix_info_extra_size(const void *beg, const void *end) +{ + int len = posix_info_parse(beg, end, NULL); + + if (len < 0) + return -1; + return len - sizeof(struct smb2_posix_info); +} + static unsigned int num_entries(char *bufstart, char *end_of_buf, char **lastentry, size_t size) { diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h index 3addecebc25d..700311978523 100644 --- a/fs/cifs/smb2pdu.h +++ b/fs/cifs/smb2pdu.h @@ -1613,5 +1613,49 @@ struct create_posix_rsp { * var sized group SID */ } __packed; + +/* + * SMB2-only POSIX info level + * + * See posix_info_sid_size(), posix_info_extra_size() and + * posix_info_parse() to help with the handling of this struct. + */ +struct smb2_posix_info { + __le32 NextEntryOffset; + __u32 Ignored; + __le64 CreationTime; + __le64 LastAccessTime; + __le64 LastWriteTime; + __le64 ChangeTime; + __le64 EndOfFile; + __le64 AllocationSize; + __le32 DosAttributes; + __le64 Inode; + __le32 DeviceId; + __le32 Zero; + /* beginning of POSIX Create Context Response */ + __le32 HardLinks; + __le32 ReparseTag; + __le32 Mode; + /* + * var sized owner SID + * var sized group SID + * le32 filenamelength + * u8 filename[] + */ +} __packed; + +/* + * Parsed version of the above struct. Allows direct access to the + * variable length fields + */ +struct smb2_posix_info_parsed { + const struct smb2_posix_info *base; + size_t size; + struct cifs_sid owner; + struct cifs_sid group; + int name_len; + const u8 *name; }; + #endif /* _SMB2PDU_H */ diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h index de6388ef344f..c0f0801e7e8e 100644 --- a/fs/cifs/smb2proto.h +++ b/fs/cifs/smb2proto.h @@ -272,4 +272,6 @@ extern int smb2_query_info_compound(const unsigned int xid, u32 class, u32 type, u32 output_len, struct kvec *rsp, int *buftype, struct cifs_sb_info *cifs_sb); +int posix_info_parse(const void *beg, const void *end, + struct smb2_posix_info_parsed *out); #endif /* _SMB2PROTO_H */ -- cgit v1.2.3