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-rw-r--r--source3/smbd/server.c340
1 files changed, 258 insertions, 82 deletions
diff --git a/source3/smbd/server.c b/source3/smbd/server.c
index 408d5cd068..59fd45f75e 100644
--- a/source3/smbd/server.c
+++ b/source3/smbd/server.c
@@ -1038,6 +1038,47 @@ static int fd_attempt_open(char *fname, int flags, int mode)
}
/****************************************************************************
+Cache a uid_t currently with this file open. This is an optimization only
+used when multiple sessionsetup's have been done to one smbd.
+****************************************************************************/
+static void fd_add_to_uid_cache(file_fd_struct *fd_ptr, uid_t u)
+{
+ if(fd_ptr->uid_cache_count >= sizeof(fd_ptr->uid_users_cache)/sizeof(uid_t))
+ return;
+ fd_ptr->uid_users_cache[fd_ptr->uid_cache_count++] = u;
+}
+
+/****************************************************************************
+Remove a uid_t that currently has this file open. This is an optimization only
+used when multiple sessionsetup's have been done to one smbd.
+****************************************************************************/
+static void fd_remove_from_uid_cache(file_fd_struct *fd_ptr, uid_t u)
+{
+ int i;
+ for(i = 0; i < fd_ptr->uid_cache_count; i++)
+ if(fd_ptr->uid_users_cache[i] == u) {
+ if(i < (fd_ptr->uid_cache_count-1))
+ memmove((char *)&fd_ptr->uid_users_cache[i], (char *)&fd_ptr->uid_users_cache[i+1],
+ sizeof(uid_t)*(fd_ptr->uid_cache_count-1-i) );
+ fd_ptr->uid_cache_count--;
+ }
+ return;
+}
+
+/****************************************************************************
+Check if a uid_t that currently has this file open is present. This is an
+optimization only used when multiple sessionsetup's have been done to one smbd.
+****************************************************************************/
+static BOOL fd_is_in_uid_cache(file_fd_struct *fd_ptr, uid_t u)
+{
+ int i;
+ for(i = 0; i < fd_ptr->uid_cache_count; i++)
+ if(fd_ptr->uid_users_cache[i] == u)
+ return True;
+ return False;
+}
+
+/****************************************************************************
fd support routines - attempt to find an already open file by dev
and inode - increments the ref_count of the returned file_fd_struct *.
****************************************************************************/
@@ -1070,6 +1111,7 @@ Increments the ref_count of the returned entry.
****************************************************************************/
static file_fd_struct *fd_get_new(void)
{
+ extern struct current_user current_user;
int i;
file_fd_struct *fd_ptr;
@@ -1082,9 +1124,11 @@ static file_fd_struct *fd_get_new(void)
fd_ptr->fd_readonly = -1;
fd_ptr->fd_writeonly = -1;
fd_ptr->real_open_flags = -1;
+ fd_ptr->uid_cache_count = 0;
+ fd_add_to_uid_cache(fd_ptr, (uid_t)current_user.uid);
fd_ptr->ref_count++;
/* Increment max used counter if neccessary, cuts down
- on search time when re-using */
+ on search time when re-using */
if(i > max_file_fd_used)
max_file_fd_used = i;
DEBUG(3,("Allocated new file_fd_struct %d, dev = %x, inode = %x\n",
@@ -1122,32 +1166,107 @@ Decrements the ref_count and returns it.
****************************************************************************/
static int fd_attempt_close(file_fd_struct *fd_ptr)
{
+ extern struct current_user current_user;
+
DEBUG(3,("fd_attempt_close on file_fd_struct %d, fd = %d, dev = %x, inode = %x, open_flags = %d, ref_count = %d.\n",
- fd_ptr - &FileFd[0],
- fd_ptr->fd, fd_ptr->dev, fd_ptr->inode,
- fd_ptr->real_open_flags,
- fd_ptr->ref_count));
+ fd_ptr - &FileFd[0],
+ fd_ptr->fd, fd_ptr->dev, fd_ptr->inode,
+ fd_ptr->real_open_flags,
+ fd_ptr->ref_count));
if(fd_ptr->ref_count > 0) {
fd_ptr->ref_count--;
if(fd_ptr->ref_count == 0) {
if(fd_ptr->fd != -1)
close(fd_ptr->fd);
if(fd_ptr->fd_readonly != -1)
- close(fd_ptr->fd_readonly);
+ close(fd_ptr->fd_readonly);
if(fd_ptr->fd_writeonly != -1)
- close(fd_ptr->fd_writeonly);
+ close(fd_ptr->fd_writeonly);
fd_ptr->fd = -1;
fd_ptr->fd_readonly = -1;
fd_ptr->fd_writeonly = -1;
fd_ptr->real_open_flags = -1;
fd_ptr->dev = (uint32)-1;
fd_ptr->inode = (uint32)-1;
- }
+ fd_ptr->uid_cache_count = 0;
+ } else
+ fd_remove_from_uid_cache(fd_ptr, (uid_t)current_user.uid);
}
return fd_ptr->ref_count;
}
/****************************************************************************
+fd support routines - check that current user has permissions
+to open this file. Used when uid not found in optimization cache.
+This is really ugly code, as due to POSIX locking braindamage we must
+fork and then attempt to open the file, and return success or failure
+via an exit code.
+****************************************************************************/
+static BOOL check_access_allowed_for_current_user( char *fname, int accmode )
+{
+ pid_t child_pid;
+
+ if((child_pid = fork()) < 0) {
+ DEBUG(0,("check_access_allowed_for_current_user: fork failed.\n"));
+ return False;
+ }
+
+ if(child_pid) {
+ /*
+ * Parent.
+ */
+ pid_t wpid;
+ int status_code;
+ if ((wpid = sys_waitpid(child_pid, &status_code, 0)) < 0) {
+ DEBUG(0,("check_access_allowed_for_current_user: The process is no longer waiting!\n"));
+ return(False);
+ }
+
+ if (child_pid != wpid) {
+ DEBUG(0,("check_access_allowed_for_current_user: We were waiting for the wrong process ID\n"));
+ return(False);
+ }
+#if defined(WIFEXITED) && defined(WEXITSTATUS)
+ if (WIFEXITED(status_code) == 0) {
+ DEBUG(0,("check_access_allowed_for_current_user: The process exited while we were waiting\n"));
+ return(False);
+ }
+ if (WEXITSTATUS(status_code) != 0) {
+ DEBUG(9,("check_access_allowed_for_current_user: The status of the process exiting was %d. Returning access denied.\n", status_code));
+ return(False);
+ }
+#else /* defined(WIFEXITED) && defined(WEXITSTATUS) */
+ if(status_code != 0) {
+ DEBUG(9,("check_access_allowed_for_current_user: The status of the process e
+xiting was %d. Returning access denied.\n", status_code));
+ return(False);
+ }
+#endif /* defined(WIFEXITED) && defined(WEXITSTATUS) */
+
+ /*
+ * Success - the child could open the file.
+ */
+ DEBUG(9,("check_access_allowed_for_current_user: The status of the process exiting was %d. Returning access allowed.\n", status_code));
+ return True;
+ } else {
+ /*
+ * Child.
+ */
+ int fd;
+ DEBUG(9,("check_access_allowed_for_current_user: Child - attempting to open %s with mode %d.\n", fname, accmode ));
+ if((fd = fd_attempt_open( fname, accmode, 0)) < 0) {
+ /* Access denied. */
+ _exit(EACCES);
+ }
+ close(fd);
+ DEBUG(9,("check_access_allowed_for_current_user: Child - returning ok.\n"));
+ _exit(0);
+ }
+
+ return False;
+}
+
+/****************************************************************************
open a file
****************************************************************************/
static void open_file(int fnum,int cnum,char *fname1,int flags,int mode, struct stat *sbuf)
@@ -1229,14 +1348,41 @@ static void open_file(int fnum,int cnum,char *fname1,int flags,int mode, struct
* reference count (fd_get_already_open increments the ref_count).
*/
if((fd_ptr = fd_get_already_open(sbuf))!= 0) {
+ /*
+ * File was already open.
+ */
- /* File was already open. */
+ /*
+ * Check it wasn't open for exclusive use.
+ */
if((flags & O_CREAT) && (flags & O_EXCL)) {
fd_ptr->ref_count--;
errno = EEXIST;
return;
}
+ /*
+ * Ensure that the user attempting to open
+ * this file has permissions to do so, if
+ * the user who originally opened the file wasn't
+ * the same as the current user.
+ */
+
+ if(!fd_is_in_uid_cache(fd_ptr, (uid_t)current_user.uid)) {
+ if(!check_access_allowed_for_current_user( fname, accmode )) {
+ /* Error - permission denied. */
+ DEBUG(3,("Permission denied opening file %s (flags=%d, accmode = %d)\n",
+ fname, flags, accmode));
+ /* Ensure the ref_count is decremented. */
+ fd_ptr->ref_count--;
+ fd_remove_from_uid_cache(fd_ptr, (uid_t)current_user.uid);
+ errno = EACCES;
+ return;
+ }
+ }
+
+ fd_add_to_uid_cache(fd_ptr, (uid_t)current_user.uid);
+
/*
* If not opened O_RDWR try
* and do that here - a chmod may have been done
@@ -1256,6 +1402,7 @@ static void open_file(int fnum,int cnum,char *fname1,int flags,int mode, struct
DEBUG(3,("Error opening (already open for flags=%d) file %s (%s) (flags=%d)\n",
fd_ptr->real_open_flags, fname,strerror(EACCES),flags));
check_for_pipe(fname);
+ fd_remove_from_uid_cache(fd_ptr, (uid_t)current_user.uid);
fd_ptr->ref_count--;
return;
}
@@ -1293,7 +1440,7 @@ static void open_file(int fnum,int cnum,char *fname1,int flags,int mode, struct
fd_ptr->fd = fd_attempt_open(fname, open_flags|O_WRONLY, mode);
fd_ptr->real_open_flags = O_WRONLY;
} else {
- fd_ptr->fd = fd_attempt_open(fname, open_flags|O_RDONLY, mode);
+ fd_ptr->fd = fd_attempt_open(fname, open_flags|O_RDONLY, mode);
fd_ptr->real_open_flags = O_RDONLY;
}
}
@@ -1319,90 +1466,91 @@ static void open_file(int fnum,int cnum,char *fname1,int flags,int mode, struct
}
if (fd_ptr->fd < 0)
- {
- DEBUG(3,("Error opening file %s (%s) (flags=%d)\n",
- fname,strerror(errno),flags));
- /* Ensure the ref_count is decremented. */
- fd_attempt_close(fd_ptr);
- check_for_pipe(fname);
- return;
- }
+ {
+ DEBUG(3,("Error opening file %s (%s) (flags=%d)\n",
+ fname,strerror(errno),flags));
+ /* Ensure the ref_count is decremented. */
+ fd_attempt_close(fd_ptr);
+ check_for_pipe(fname);
+ return;
+ }
if (fd_ptr->fd >= 0)
- {
- if(sbuf == 0) {
- /* Do the fstat */
- if(fstat(fd_ptr->fd, &statbuf) == -1) {
- /* Error - backout !! */
- DEBUG(3,("Error doing fstat on fd %d, file %s (%s)\n",
- fd_ptr->fd, fname,strerror(errno)));
- /* Ensure the ref_count is decremented. */
- fd_attempt_close(fd_ptr);
- return;
- }
- sbuf = &statbuf;
+ {
+ if(sbuf == 0) {
+ /* Do the fstat */
+ if(fstat(fd_ptr->fd, &statbuf) == -1) {
+ /* Error - backout !! */
+ DEBUG(3,("Error doing fstat on fd %d, file %s (%s)\n",
+ fd_ptr->fd, fname,strerror(errno)));
+ /* Ensure the ref_count is decremented. */
+ fd_attempt_close(fd_ptr);
+ return;
}
- /* Set the correct entries in fd_ptr. */
- fd_ptr->dev = (uint32)sbuf->st_dev;
- fd_ptr->inode = (uint32)sbuf->st_ino;
-
- fsp->fd_ptr = fd_ptr;
- Connections[cnum].num_files_open++;
- fsp->mode = sbuf->st_mode;
- GetTimeOfDay(&fsp->open_time);
- fsp->vuid = current_user.vuid;
- fsp->size = 0;
- fsp->pos = -1;
- fsp->open = True;
- fsp->mmap_ptr = NULL;
- fsp->mmap_size = 0;
- fsp->can_lock = True;
- fsp->can_read = ((flags & O_WRONLY)==0);
- fsp->can_write = ((flags & (O_WRONLY|O_RDWR))!=0);
- fsp->share_mode = 0;
- fsp->print_file = Connections[cnum].printer;
- fsp->modified = False;
- fsp->granted_oplock = False;
- fsp->sent_oplock_break = False;
- fsp->cnum = cnum;
- string_set(&fsp->name,dos_to_unix(fname,False));
- fsp->wbmpx_ptr = NULL;
+ sbuf = &statbuf;
+ }
- /*
- * If the printer is marked as postscript output a leading
- * file identifier to ensure the file is treated as a raw
- * postscript file.
- * This has a similar effect as CtrlD=0 in WIN.INI file.
- * tim@fsg.com 09/06/94
- */
- if (fsp->print_file && POSTSCRIPT(cnum) &&
- fsp->can_write)
- {
- DEBUG(3,("Writing postscript line\n"));
- write_file(fnum,"%!\n",3);
- }
-
- DEBUG(2,("%s %s opened file %s read=%s write=%s (numopen=%d fnum=%d)\n",
- timestring(),Connections[cnum].user,fname,
- BOOLSTR(fsp->can_read),BOOLSTR(fsp->can_write),
- Connections[cnum].num_files_open,fnum));
+ /* Set the correct entries in fd_ptr. */
+ fd_ptr->dev = (uint32)sbuf->st_dev;
+ fd_ptr->inode = (uint32)sbuf->st_ino;
+
+ fsp->fd_ptr = fd_ptr;
+ Connections[cnum].num_files_open++;
+ fsp->mode = sbuf->st_mode;
+ GetTimeOfDay(&fsp->open_time);
+ fsp->vuid = current_user.vuid;
+ fsp->size = 0;
+ fsp->pos = -1;
+ fsp->open = True;
+ fsp->mmap_ptr = NULL;
+ fsp->mmap_size = 0;
+ fsp->can_lock = True;
+ fsp->can_read = ((flags & O_WRONLY)==0);
+ fsp->can_write = ((flags & (O_WRONLY|O_RDWR))!=0);
+ fsp->share_mode = 0;
+ fsp->print_file = Connections[cnum].printer;
+ fsp->modified = False;
+ fsp->granted_oplock = False;
+ fsp->sent_oplock_break = False;
+ fsp->cnum = cnum;
+ string_set(&fsp->name,dos_to_unix(fname,False));
+ fsp->wbmpx_ptr = NULL;
+ /*
+ * If the printer is marked as postscript output a leading
+ * file identifier to ensure the file is treated as a raw
+ * postscript file.
+ * This has a similar effect as CtrlD=0 in WIN.INI file.
+ * tim@fsg.com 09/06/94
+ */
+ if (fsp->print_file && POSTSCRIPT(cnum) && fsp->can_write)
+ {
+ DEBUG(3,("Writing postscript line\n"));
+ write_file(fnum,"%!\n",3);
}
+
+ DEBUG(2,("%s %s opened file %s read=%s write=%s (numopen=%d fnum=%d)\n",
+ timestring(),
+ *sesssetup_user ? sesssetup_user : Connections[cnum].user,fname,
+ BOOLSTR(fsp->can_read),BOOLSTR(fsp->can_write),
+ Connections[cnum].num_files_open,fnum));
+
+ }
#if USE_MMAP
/* mmap it if read-only */
if (!fsp->can_write)
- {
- fsp->mmap_size = file_size(fname);
- fsp->mmap_ptr = (char *)mmap(NULL,fsp->mmap_size,
- PROT_READ,MAP_SHARED,fsp->fd_ptr->fd,0);
+ {
+ fsp->mmap_size = file_size(fname);
+ fsp->mmap_ptr = (char *)mmap(NULL,fsp->mmap_size,
+ PROT_READ,MAP_SHARED,fsp->fd_ptr->fd,0);
- if (fsp->mmap_ptr == (char *)-1 || !fsp->mmap_ptr)
- {
- DEBUG(3,("Failed to mmap() %s - %s\n",fname,strerror(errno)));
- fsp->mmap_ptr = NULL;
- }
+ if (fsp->mmap_ptr == (char *)-1 || !fsp->mmap_ptr)
+ {
+ DEBUG(3,("Failed to mmap() %s - %s\n",fname,strerror(errno)));
+ fsp->mmap_ptr = NULL;
}
+ }
#endif
}
@@ -2867,6 +3015,7 @@ pid %d, port %d, dev = %x, inode = %x\n", remotepid, from_port, dev, inode));
****************************************************************************/
BOOL oplock_break(uint32 dev, uint32 inode, struct timeval *tval)
{
+ extern struct current_user current_user;
extern int Client;
char *inbuf = NULL;
char *outbuf = NULL;
@@ -2874,6 +3023,9 @@ BOOL oplock_break(uint32 dev, uint32 inode, struct timeval *tval)
int fnum;
time_t start_time;
BOOL shutdown_server = False;
+ int saved_cnum;
+ int saved_vuid;
+ pstring saved_dir;
DEBUG(3,("%s oplock_break: called for dev = %x, inode = %x. Current \
global_oplocks_open = %d\n", timestring(), dev, inode, global_oplocks_open));
@@ -2979,6 +3131,15 @@ allowing break to succeed.\n", timestring(), dev, inode, fnum));
start_time = time(NULL);
+ /*
+ * Save the information we need to re-become the
+ * user, then unbecome the user whilst we're doing this.
+ */
+ saved_cnum = fsp->cnum;
+ saved_vuid = current_user.vuid;
+ GetWd(saved_dir);
+ unbecome_user();
+
while(OPEN_FNUM(fnum) && fsp->granted_oplock)
{
if(receive_smb(Client,inbuf,OPLOCK_BREAK_TIMEOUT * 1000) == False)
@@ -3030,6 +3191,21 @@ inode = %x).\n", timestring(), fsp->name, fnum, dev, inode));
}
}
+ /*
+ * Go back to being the user who requested the oplock
+ * break.
+ */
+ if(!become_user(&Connections[saved_cnum], saved_cnum, saved_vuid))
+ {
+ DEBUG(0,("%s oplock_break: unable to re-become user ! Shutting down server\n",
+ timestring()));
+ close_sockets();
+ close(oplock_sock);
+ exit_server("unable to re-become user");
+ }
+ /* Including the directory. */
+ ChDir(saved_dir);
+
/* Free the buffers we've been using to recurse. */
free(inbuf);
free(outbuf);
generated by cgit (git 2.34.1) at 2024-12-11 11:01:31 +0000