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author | pjd <pjd@FreeBSD.org> | 2013-03-02 00:53:12 +0000 |
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committer | pjd <pjd@FreeBSD.org> | 2013-03-02 00:53:12 +0000 |
commit | f07ebb8888ea42f744890a727e8f6799a1086915 (patch) | |
tree | 90495ae13fcc0dd621d97fc1b788f43780023c0a /sys/kern/sys_generic.c | |
parent | dd15932a159ec60641cd20e4fb689fa28d75465d (diff) | |
download | FreeBSD-src-f07ebb8888ea42f744890a727e8f6799a1086915.zip FreeBSD-src-f07ebb8888ea42f744890a727e8f6799a1086915.tar.gz |
Merge Capsicum overhaul:
- Capability is no longer separate descriptor type. Now every descriptor
has set of its own capability rights.
- The cap_new(2) system call is left, but it is no longer documented and
should not be used in new code.
- The new syscall cap_rights_limit(2) should be used instead of
cap_new(2), which limits capability rights of the given descriptor
without creating a new one.
- The cap_getrights(2) syscall is renamed to cap_rights_get(2).
- If CAP_IOCTL capability right is present we can further reduce allowed
ioctls list with the new cap_ioctls_limit(2) syscall. List of allowed
ioctls can be retrived with cap_ioctls_get(2) syscall.
- If CAP_FCNTL capability right is present we can further reduce fcntls
that can be used with the new cap_fcntls_limit(2) syscall and retrive
them with cap_fcntls_get(2).
- To support ioctl and fcntl white-listing the filedesc structure was
heavly modified.
- The audit subsystem, kdump and procstat tools were updated to
recognize new syscalls.
- Capability rights were revised and eventhough I tried hard to provide
backward API and ABI compatibility there are some incompatible changes
that are described in detail below:
CAP_CREATE old behaviour:
- Allow for openat(2)+O_CREAT.
- Allow for linkat(2).
- Allow for symlinkat(2).
CAP_CREATE new behaviour:
- Allow for openat(2)+O_CREAT.
Added CAP_LINKAT:
- Allow for linkat(2). ABI: Reuses CAP_RMDIR bit.
- Allow to be target for renameat(2).
Added CAP_SYMLINKAT:
- Allow for symlinkat(2).
Removed CAP_DELETE. Old behaviour:
- Allow for unlinkat(2) when removing non-directory object.
- Allow to be source for renameat(2).
Removed CAP_RMDIR. Old behaviour:
- Allow for unlinkat(2) when removing directory.
Added CAP_RENAMEAT:
- Required for source directory for the renameat(2) syscall.
Added CAP_UNLINKAT (effectively it replaces CAP_DELETE and CAP_RMDIR):
- Allow for unlinkat(2) on any object.
- Required if target of renameat(2) exists and will be removed by this
call.
Removed CAP_MAPEXEC.
CAP_MMAP old behaviour:
- Allow for mmap(2) with any combination of PROT_NONE, PROT_READ and
PROT_WRITE.
CAP_MMAP new behaviour:
- Allow for mmap(2)+PROT_NONE.
Added CAP_MMAP_R:
- Allow for mmap(PROT_READ).
Added CAP_MMAP_W:
- Allow for mmap(PROT_WRITE).
Added CAP_MMAP_X:
- Allow for mmap(PROT_EXEC).
Added CAP_MMAP_RW:
- Allow for mmap(PROT_READ | PROT_WRITE).
Added CAP_MMAP_RX:
- Allow for mmap(PROT_READ | PROT_EXEC).
Added CAP_MMAP_WX:
- Allow for mmap(PROT_WRITE | PROT_EXEC).
Added CAP_MMAP_RWX:
- Allow for mmap(PROT_READ | PROT_WRITE | PROT_EXEC).
Renamed CAP_MKDIR to CAP_MKDIRAT.
Renamed CAP_MKFIFO to CAP_MKFIFOAT.
Renamed CAP_MKNODE to CAP_MKNODEAT.
CAP_READ old behaviour:
- Allow pread(2).
- Disallow read(2), readv(2) (if there is no CAP_SEEK).
CAP_READ new behaviour:
- Allow read(2), readv(2).
- Disallow pread(2) (CAP_SEEK was also required).
CAP_WRITE old behaviour:
- Allow pwrite(2).
- Disallow write(2), writev(2) (if there is no CAP_SEEK).
CAP_WRITE new behaviour:
- Allow write(2), writev(2).
- Disallow pwrite(2) (CAP_SEEK was also required).
Added convinient defines:
#define CAP_PREAD (CAP_SEEK | CAP_READ)
#define CAP_PWRITE (CAP_SEEK | CAP_WRITE)
#define CAP_MMAP_R (CAP_MMAP | CAP_SEEK | CAP_READ)
#define CAP_MMAP_W (CAP_MMAP | CAP_SEEK | CAP_WRITE)
#define CAP_MMAP_X (CAP_MMAP | CAP_SEEK | 0x0000000000000008ULL)
#define CAP_MMAP_RW (CAP_MMAP_R | CAP_MMAP_W)
#define CAP_MMAP_RX (CAP_MMAP_R | CAP_MMAP_X)
#define CAP_MMAP_WX (CAP_MMAP_W | CAP_MMAP_X)
#define CAP_MMAP_RWX (CAP_MMAP_R | CAP_MMAP_W | CAP_MMAP_X)
#define CAP_RECV CAP_READ
#define CAP_SEND CAP_WRITE
#define CAP_SOCK_CLIENT \
(CAP_CONNECT | CAP_GETPEERNAME | CAP_GETSOCKNAME | CAP_GETSOCKOPT | \
CAP_PEELOFF | CAP_RECV | CAP_SEND | CAP_SETSOCKOPT | CAP_SHUTDOWN)
#define CAP_SOCK_SERVER \
(CAP_ACCEPT | CAP_BIND | CAP_GETPEERNAME | CAP_GETSOCKNAME | \
CAP_GETSOCKOPT | CAP_LISTEN | CAP_PEELOFF | CAP_RECV | CAP_SEND | \
CAP_SETSOCKOPT | CAP_SHUTDOWN)
Added defines for backward API compatibility:
#define CAP_MAPEXEC CAP_MMAP_X
#define CAP_DELETE CAP_UNLINKAT
#define CAP_MKDIR CAP_MKDIRAT
#define CAP_RMDIR CAP_UNLINKAT
#define CAP_MKFIFO CAP_MKFIFOAT
#define CAP_MKNOD CAP_MKNODAT
#define CAP_SOCK_ALL (CAP_SOCK_CLIENT | CAP_SOCK_SERVER)
Sponsored by: The FreeBSD Foundation
Reviewed by: Christoph Mallon <christoph.mallon@gmx.de>
Many aspects discussed with: rwatson, benl, jonathan
ABI compatibility discussed with: kib
Diffstat (limited to 'sys/kern/sys_generic.c')
-rw-r--r-- | sys/kern/sys_generic.c | 131 |
1 files changed, 78 insertions, 53 deletions
diff --git a/sys/kern/sys_generic.c b/sys/kern/sys_generic.c index b97ff7f..39f33f3 100644 --- a/sys/kern/sys_generic.c +++ b/sys/kern/sys_generic.c @@ -49,6 +49,7 @@ __FBSDID("$FreeBSD$"); #include <sys/filio.h> #include <sys/fcntl.h> #include <sys/file.h> +#include <sys/lock.h> #include <sys/proc.h> #include <sys/signalvar.h> #include <sys/socketvar.h> @@ -244,7 +245,7 @@ kern_readv(struct thread *td, int fd, struct uio *auio) struct file *fp; int error; - error = fget_read(td, fd, CAP_READ | CAP_SEEK, &fp); + error = fget_read(td, fd, CAP_READ, &fp); if (error) return (error); error = dofileread(td, fd, fp, auio, (off_t)-1, 0); @@ -287,7 +288,7 @@ kern_preadv(td, fd, auio, offset) struct file *fp; int error; - error = fget_read(td, fd, CAP_READ, &fp); + error = fget_read(td, fd, CAP_PREAD, &fp); if (error) return (error); if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) @@ -453,7 +454,7 @@ kern_writev(struct thread *td, int fd, struct uio *auio) struct file *fp; int error; - error = fget_write(td, fd, CAP_WRITE | CAP_SEEK, &fp); + error = fget_write(td, fd, CAP_WRITE, &fp); if (error) return (error); error = dofilewrite(td, fd, fp, auio, (off_t)-1, 0); @@ -496,7 +497,7 @@ kern_pwritev(td, fd, auio, offset) struct file *fp; int error; - error = fget_write(td, fd, CAP_WRITE, &fp); + error = fget_write(td, fd, CAP_PWRITE, &fp); if (error) return (error); if (!(fp->f_ops->fo_flags & DFLAG_SEEKABLE)) @@ -704,28 +705,60 @@ kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data) { struct file *fp; struct filedesc *fdp; - int error; - int tmp; + int error, tmp, locked; AUDIT_ARG_FD(fd); AUDIT_ARG_CMD(com); - if ((error = fget(td, fd, CAP_IOCTL, &fp)) != 0) - return (error); - if ((fp->f_flag & (FREAD | FWRITE)) == 0) { - fdrop(fp, td); - return (EBADF); - } + fdp = td->td_proc->p_fd; + switch (com) { case FIONCLEX: + case FIOCLEX: FILEDESC_XLOCK(fdp); - fdp->fd_ofileflags[fd] &= ~UF_EXCLOSE; - FILEDESC_XUNLOCK(fdp); + locked = LA_XLOCKED; + break; + default: +#ifdef CAPABILITIES + FILEDESC_SLOCK(fdp); + locked = LA_SLOCKED; +#else + locked = LA_UNLOCKED; +#endif + break; + } + +#ifdef CAPABILITIES + if ((fp = fget_locked(fdp, fd)) == NULL) { + error = EBADF; + goto out; + } + if ((error = cap_ioctl_check(fdp, fd, com)) != 0) { + fp = NULL; /* fhold() was not called yet */ + goto out; + } + fhold(fp); + if (locked == LA_SLOCKED) { + FILEDESC_SUNLOCK(fdp); + locked = LA_UNLOCKED; + } +#else + if ((error = fget(td, fd, CAP_IOCTL, &fp)) != 0) { + fp = NULL; + goto out; + } +#endif + if ((fp->f_flag & (FREAD | FWRITE)) == 0) { + error = EBADF; + goto out; + } + + switch (com) { + case FIONCLEX: + fdp->fd_ofiles[fd].fde_flags &= ~UF_EXCLOSE; goto out; case FIOCLEX: - FILEDESC_XLOCK(fdp); - fdp->fd_ofileflags[fd] |= UF_EXCLOSE; - FILEDESC_XUNLOCK(fdp); + fdp->fd_ofiles[fd].fde_flags |= UF_EXCLOSE; goto out; case FIONBIO: if ((tmp = *(int *)data)) @@ -745,7 +778,21 @@ kern_ioctl(struct thread *td, int fd, u_long com, caddr_t data) error = fo_ioctl(fp, com, data, td->td_ucred, td); out: - fdrop(fp, td); + switch (locked) { + case LA_XLOCKED: + FILEDESC_XUNLOCK(fdp); + break; +#ifdef CAPABILITIES + case LA_SLOCKED: + FILEDESC_SUNLOCK(fdp); + break; +#endif + default: + FILEDESC_UNLOCK_ASSERT(fdp); + break; + } + if (fp != NULL) + fdrop(fp, td); return (error); } @@ -1130,32 +1177,8 @@ selsetbits(fd_mask **ibits, fd_mask **obits, int idx, fd_mask bit, int events) static __inline int getselfd_cap(struct filedesc *fdp, int fd, struct file **fpp) { - struct file *fp; -#ifdef CAPABILITIES - struct file *fp_fromcap; - int error; -#endif - if ((fp = fget_unlocked(fdp, fd)) == NULL) - return (EBADF); -#ifdef CAPABILITIES - /* - * If the file descriptor is for a capability, test rights and use - * the file descriptor references by the capability. - */ - error = cap_funwrap(fp, CAP_POLL_EVENT, &fp_fromcap); - if (error) { - fdrop(fp, curthread); - return (error); - } - if (fp != fp_fromcap) { - fhold(fp_fromcap); - fdrop(fp, curthread); - fp = fp_fromcap; - } -#endif /* CAPABILITIES */ - *fpp = fp; - return (0); + return (fget_unlocked(fdp, fd, CAP_POLL_EVENT, 0, fpp, NULL)); } /* @@ -1349,13 +1372,14 @@ pollrescan(struct thread *td) /* If the selinfo wasn't cleared the event didn't fire. */ if (si != NULL) continue; - fp = fdp->fd_ofiles[fd->fd]; + fp = fdp->fd_ofiles[fd->fd].fde_file; #ifdef CAPABILITIES - if ((fp == NULL) - || (cap_funwrap(fp, CAP_POLL_EVENT, &fp) != 0)) { + if (fp == NULL || + cap_check(cap_rights(fdp, fd->fd), CAP_POLL_EVENT) != 0) #else - if (fp == NULL) { + if (fp == NULL) #endif + { fd->revents = POLLNVAL; n++; continue; @@ -1408,9 +1432,8 @@ pollscan(td, fds, nfd) u_int nfd; { struct filedesc *fdp = td->td_proc->p_fd; - int i; struct file *fp; - int n = 0; + int i, n = 0; FILEDESC_SLOCK(fdp); for (i = 0; i < nfd; i++, fds++) { @@ -1420,13 +1443,15 @@ pollscan(td, fds, nfd) } else if (fds->fd < 0) { fds->revents = 0; } else { - fp = fdp->fd_ofiles[fds->fd]; + fp = fdp->fd_ofiles[fds->fd].fde_file; #ifdef CAPABILITIES - if ((fp == NULL) - || (cap_funwrap(fp, CAP_POLL_EVENT, &fp) != 0)) { + if (fp == NULL || + cap_check(cap_rights(fdp, fds->fd), + CAP_POLL_EVENT) != 0) #else - if (fp == NULL) { + if (fp == NULL) #endif + { fds->revents = POLLNVAL; n++; } else { |