Paul Bryan Roberts : server: Refactor server side implementation of GetFileSecurity().
Module: wine Branch: master Commit: d87af3dfb23dcb016a9eeaf6266d7f81976655b6 URL: http://source.winehq.org/git/wine.git/?a=commit;h=d87af3dfb23dcb016a9eeaf626... Author: Paul Bryan Roberts <pbronline-wine(a)yahoo.co.uk> Date: Mon Nov 3 22:25:37 2008 +0000 server: Refactor server side implementation of GetFileSecurity(). --- server/file.c | 102 +++++++++++++++++++++++++++++--------------------------- server/file.h | 2 + 2 files changed, 55 insertions(+), 49 deletions(-) diff --git a/server/file.c b/server/file.c index 5224e85..dc93b4b 100644 --- a/server/file.c +++ b/server/file.c @@ -75,7 +75,6 @@ static void file_destroy( struct object *obj ); static int file_get_poll_events( struct fd *fd ); static void file_flush( struct fd *fd, struct event **event ); static enum server_fd_type file_get_fd_type( struct fd *fd ); -static mode_t sd_to_mode( const struct security_descriptor *sd, const SID *owner ); static const struct object_ops file_ops = { @@ -291,14 +290,9 @@ static unsigned int generic_file_map_access( unsigned int access ) return access & ~(GENERIC_READ | GENERIC_WRITE | GENERIC_EXECUTE | GENERIC_ALL); } -static struct security_descriptor *file_get_sd( struct object *obj ) +struct security_descriptor *mode_to_sd( mode_t mode, const SID *user, const SID *group ) { - struct file *file = (struct file *)obj; - struct stat st; - int unix_fd; struct security_descriptor *sd; - const SID *user; - const SID *group; size_t dacl_size; ACE_HEADER *current_ace; ACCESS_ALLOWED_ACE *aaa; @@ -308,34 +302,17 @@ static struct security_descriptor *file_get_sd( struct object *obj ) const SID *world_sid = security_world_sid; const SID *local_system_sid = security_local_system_sid; - assert( obj->ops == &file_ops ); - - unix_fd = get_file_unix_fd( file ); - - if (unix_fd == -1) return obj->sd; - - if (fstat( unix_fd, &st ) == -1) - return obj->sd; - - /* mode and uid the same? if so, no need to re-generate security descriptor */ - if (obj->sd && (st.st_mode & (S_IRWXU|S_IRWXO)) == (file->mode & (S_IRWXU|S_IRWXO)) && - (st.st_uid == file->uid)) - return obj->sd; - - user = security_unix_uid_to_sid( st.st_uid ); - group = token_get_primary_group( current->process->token ); - dacl_size = sizeof(ACL) + FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) + FIELD_OFFSET(SID, SubAuthority[local_system_sid->SubAuthorityCount]); - if (st.st_mode & S_IRWXU) + if (mode & S_IRWXU) dacl_size += FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) + FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]); - if ((!(st.st_mode & S_IRUSR) && (st.st_mode & (S_IRGRP|S_IROTH))) || - (!(st.st_mode & S_IWUSR) && (st.st_mode & (S_IWGRP|S_IWOTH))) || - (!(st.st_mode & S_IXUSR) && (st.st_mode & (S_IXGRP|S_IXOTH)))) + if ((!(mode & S_IRUSR) && (mode & (S_IRGRP|S_IROTH))) || + (!(mode & S_IWUSR) && (mode & (S_IWGRP|S_IWOTH))) || + (!(mode & S_IXUSR) && (mode & (S_IXGRP|S_IXOTH)))) dacl_size += FIELD_OFFSET(ACCESS_DENIED_ACE, SidStart) + FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]); - if (st.st_mode & S_IRWXO) + if (mode & S_IRWXO) dacl_size += FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) + FIELD_OFFSET(SID, SubAuthority[world_sid->SubAuthorityCount]); @@ -343,7 +320,7 @@ static struct security_descriptor *file_get_sd( struct object *obj ) FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]) + FIELD_OFFSET(SID, SubAuthority[group->SubAuthorityCount]) + dacl_size ); - if (!sd) return obj->sd; + if (!sd) return sd; sd->control = SE_DACL_PRESENT; sd->owner_len = FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]); @@ -361,10 +338,10 @@ static struct security_descriptor *file_get_sd( struct object *obj ) dacl->AclRevision = ACL_REVISION; dacl->Sbz1 = 0; dacl->AclSize = dacl_size; - dacl->AceCount = 1 + (st.st_mode & S_IRWXU ? 1 : 0) + (st.st_mode & S_IRWXO ? 1 : 0); - if ((!(st.st_mode & S_IRUSR) && (st.st_mode & (S_IRGRP|S_IROTH))) || - (!(st.st_mode & S_IWUSR) && (st.st_mode & (S_IWGRP|S_IWOTH))) || - (!(st.st_mode & S_IXUSR) && (st.st_mode & (S_IXGRP|S_IXOTH)))) + dacl->AceCount = 1 + (mode & S_IRWXU ? 1 : 0) + (mode & S_IRWXO ? 1 : 0); + if ((!(mode & S_IRUSR) && (mode & (S_IRGRP|S_IROTH))) || + (!(mode & S_IWUSR) && (mode & (S_IWGRP|S_IWOTH))) || + (!(mode & S_IXUSR) && (mode & (S_IXGRP|S_IXOTH)))) dacl->AceCount++; dacl->Sbz2 = 0; @@ -379,7 +356,7 @@ static struct security_descriptor *file_get_sd( struct object *obj ) sid = (SID *)&aaa->SidStart; memcpy( sid, local_system_sid, FIELD_OFFSET(SID, SubAuthority[local_system_sid->SubAuthorityCount]) ); - if (st.st_mode & S_IRWXU) + if (mode & S_IRWXU) { /* appropriate access rights for the user */ aaa = (ACCESS_ALLOWED_ACE *)ace_next( current_ace ); @@ -389,18 +366,18 @@ static struct security_descriptor *file_get_sd( struct object *obj ) aaa->Header.AceSize = FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) + FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]); aaa->Mask = WRITE_DAC | WRITE_OWNER; - if (st.st_mode & S_IRUSR) + if (mode & S_IRUSR) aaa->Mask |= FILE_GENERIC_READ; - if (st.st_mode & S_IWUSR) + if (mode & S_IWUSR) aaa->Mask |= FILE_GENERIC_WRITE | DELETE; - if (st.st_mode & S_IXUSR) + if (mode & S_IXUSR) aaa->Mask |= FILE_GENERIC_EXECUTE; sid = (SID *)&aaa->SidStart; memcpy( sid, user, FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]) ); } - if ((!(st.st_mode & S_IRUSR) && (st.st_mode & (S_IRGRP|S_IROTH))) || - (!(st.st_mode & S_IWUSR) && (st.st_mode & (S_IWGRP|S_IWOTH))) || - (!(st.st_mode & S_IXUSR) && (st.st_mode & (S_IXGRP|S_IXOTH)))) + if ((!(mode & S_IRUSR) && (mode & (S_IRGRP|S_IROTH))) || + (!(mode & S_IWUSR) && (mode & (S_IWGRP|S_IWOTH))) || + (!(mode & S_IXUSR) && (mode & (S_IXGRP|S_IXOTH)))) { /* deny just in case the user is a member of the group */ ACCESS_DENIED_ACE *ada = (ACCESS_DENIED_ACE *)ace_next( current_ace ); @@ -410,17 +387,17 @@ static struct security_descriptor *file_get_sd( struct object *obj ) ada->Header.AceSize = FIELD_OFFSET(ACCESS_DENIED_ACE, SidStart) + FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]); ada->Mask = 0; - if (!(st.st_mode & S_IRUSR) && (st.st_mode & (S_IRGRP|S_IROTH))) + if (!(mode & S_IRUSR) && (mode & (S_IRGRP|S_IROTH))) ada->Mask |= FILE_GENERIC_READ; - if (!(st.st_mode & S_IWUSR) && (st.st_mode & (S_IWGRP|S_IROTH))) + if (!(mode & S_IWUSR) && (mode & (S_IWGRP|S_IROTH))) ada->Mask |= FILE_GENERIC_WRITE | DELETE; - if (!(st.st_mode & S_IXUSR) && (st.st_mode & (S_IXGRP|S_IXOTH))) + if (!(mode & S_IXUSR) && (mode & (S_IXGRP|S_IXOTH))) ada->Mask |= FILE_GENERIC_EXECUTE; ada->Mask &= ~STANDARD_RIGHTS_ALL; /* never deny standard rights */ sid = (SID *)&ada->SidStart; memcpy( sid, user, FIELD_OFFSET(SID, SubAuthority[user->SubAuthorityCount]) ); } - if (st.st_mode & S_IRWXO) + if (mode & S_IRWXO) { /* appropriate access rights for Everyone */ aaa = (ACCESS_ALLOWED_ACE *)ace_next( current_ace ); @@ -430,16 +407,43 @@ static struct security_descriptor *file_get_sd( struct object *obj ) aaa->Header.AceSize = FIELD_OFFSET(ACCESS_ALLOWED_ACE, SidStart) + FIELD_OFFSET(SID, SubAuthority[world_sid->SubAuthorityCount]); aaa->Mask = 0; - if (st.st_mode & S_IROTH) + if (mode & S_IROTH) aaa->Mask |= FILE_GENERIC_READ; - if (st.st_mode & S_IWOTH) + if (mode & S_IWOTH) aaa->Mask |= FILE_GENERIC_WRITE | DELETE; - if (st.st_mode & S_IXOTH) + if (mode & S_IXOTH) aaa->Mask |= FILE_GENERIC_EXECUTE; sid = (SID *)&aaa->SidStart; memcpy( sid, world_sid, FIELD_OFFSET(SID, SubAuthority[world_sid->SubAuthorityCount]) ); } + return sd; +} + +static struct security_descriptor *file_get_sd( struct object *obj ) +{ + struct file *file = (struct file *)obj; + struct stat st; + int unix_fd; + struct security_descriptor *sd; + + assert( obj->ops == &file_ops ); + + unix_fd = get_file_unix_fd( file ); + + if (unix_fd == -1 || fstat( unix_fd, &st ) == -1) + return obj->sd; + + /* mode and uid the same? if so, no need to re-generate security descriptor */ + if (obj->sd && (st.st_mode & (S_IRWXU|S_IRWXO)) == (file->mode & (S_IRWXU|S_IRWXO)) && + (st.st_uid == file->uid)) + return obj->sd; + + sd = mode_to_sd( st.st_mode, + security_unix_uid_to_sid( st.st_uid ), + token_get_primary_group( current->process->token )); + if (!sd) return obj->sd; + file->mode = st.st_mode; file->uid = st.st_uid; free( obj->sd ); @@ -447,7 +451,7 @@ static struct security_descriptor *file_get_sd( struct object *obj ) return sd; } -static mode_t sd_to_mode( const struct security_descriptor *sd, const SID *owner ) +mode_t sd_to_mode( const struct security_descriptor *sd, const SID *owner ) { mode_t new_mode = 0; mode_t denied_mode = 0; diff --git a/server/file.h b/server/file.h index 26d1702..2d1d047 100644 --- a/server/file.h +++ b/server/file.h @@ -112,6 +112,8 @@ extern struct file *grab_file_unless_removable( struct file *file ); extern int grow_file( struct file *file, file_pos_t size ); extern struct file *create_temp_file( int access ); extern void file_set_error(void); +extern struct security_descriptor *mode_to_sd( mode_t mode, const SID *user, const SID *group ); +extern mode_t sd_to_mode( const struct security_descriptor *sd, const SID *owner ); /* change notification functions */
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Alexandre Julliard