From: Vivek Goyal <vgo...@redhat.com> Add capability to enable and parse security context as sent by client and put into fuse_req. Filesystems now can get security context from request and set it on files during creation.
Signed-off-by: Vivek Goyal <vgo...@redhat.com> Message-Id: <20220208204813.682906-6-vgo...@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com> --- tools/virtiofsd/fuse_common.h | 5 ++ tools/virtiofsd/fuse_i.h | 7 +++ tools/virtiofsd/fuse_lowlevel.c | 102 +++++++++++++++++++++++++++++++- 3 files changed, 113 insertions(+), 1 deletion(-) diff --git a/tools/virtiofsd/fuse_common.h b/tools/virtiofsd/fuse_common.h index 6f8a988202..bf46954dab 100644 --- a/tools/virtiofsd/fuse_common.h +++ b/tools/virtiofsd/fuse_common.h @@ -377,6 +377,11 @@ struct fuse_file_info { */ #define FUSE_CAP_SETXATTR_EXT (1 << 29) +/** + * Indicates that file server supports creating file security context + */ +#define FUSE_CAP_SECURITY_CTX (1ULL << 32) + /** * Ioctl flags * diff --git a/tools/virtiofsd/fuse_i.h b/tools/virtiofsd/fuse_i.h index 492e002181..a5572fa4ae 100644 --- a/tools/virtiofsd/fuse_i.h +++ b/tools/virtiofsd/fuse_i.h @@ -15,6 +15,12 @@ struct fv_VuDev; struct fv_QueueInfo; +struct fuse_security_context { + const char *name; + uint32_t ctxlen; + const void *ctx; +}; + struct fuse_req { struct fuse_session *se; uint64_t unique; @@ -35,6 +41,7 @@ struct fuse_req { } u; struct fuse_req *next; struct fuse_req *prev; + struct fuse_security_context secctx; }; struct fuse_notify_req { diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c index d91cd9743a..2909122b23 100644 --- a/tools/virtiofsd/fuse_lowlevel.c +++ b/tools/virtiofsd/fuse_lowlevel.c @@ -886,11 +886,63 @@ static void do_readlink(fuse_req_t req, fuse_ino_t nodeid, } } +static int parse_secctx_fill_req(fuse_req_t req, struct fuse_mbuf_iter *iter) +{ + struct fuse_secctx_header *fsecctx_header; + struct fuse_secctx *fsecctx; + const void *secctx; + const char *name; + + fsecctx_header = fuse_mbuf_iter_advance(iter, sizeof(*fsecctx_header)); + if (!fsecctx_header) { + return -EINVAL; + } + + /* + * As of now maximum of one security context is supported. It can + * change in future though. + */ + if (fsecctx_header->nr_secctx > 1) { + return -EINVAL; + } + + /* No security context sent. Maybe no LSM supports it */ + if (!fsecctx_header->nr_secctx) { + return 0; + } + + fsecctx = fuse_mbuf_iter_advance(iter, sizeof(*fsecctx)); + if (!fsecctx) { + return -EINVAL; + } + + /* struct fsecctx with zero sized context is not expected */ + if (!fsecctx->size) { + return -EINVAL; + } + name = fuse_mbuf_iter_advance_str(iter); + if (!name) { + return -EINVAL; + } + + secctx = fuse_mbuf_iter_advance(iter, fsecctx->size); + if (!secctx) { + return -EINVAL; + } + + req->secctx.name = name; + req->secctx.ctx = secctx; + req->secctx.ctxlen = fsecctx->size; + return 0; +} + static void do_mknod(fuse_req_t req, fuse_ino_t nodeid, struct fuse_mbuf_iter *iter) { struct fuse_mknod_in *arg; const char *name; + bool secctx_enabled = req->se->conn.want & FUSE_CAP_SECURITY_CTX; + int err; arg = fuse_mbuf_iter_advance(iter, sizeof(*arg)); name = fuse_mbuf_iter_advance_str(iter); @@ -901,6 +953,14 @@ static void do_mknod(fuse_req_t req, fuse_ino_t nodeid, req->ctx.umask = arg->umask; + if (secctx_enabled) { + err = parse_secctx_fill_req(req, iter); + if (err) { + fuse_reply_err(req, -err); + return; + } + } + if (req->se->op.mknod) { req->se->op.mknod(req, nodeid, name, arg->mode, arg->rdev); } else { @@ -913,6 +973,8 @@ static void do_mkdir(fuse_req_t req, fuse_ino_t nodeid, { struct fuse_mkdir_in *arg; const char *name; + bool secctx_enabled = req->se->conn.want & FUSE_CAP_SECURITY_CTX; + int err; arg = fuse_mbuf_iter_advance(iter, sizeof(*arg)); name = fuse_mbuf_iter_advance_str(iter); @@ -923,6 +985,14 @@ static void do_mkdir(fuse_req_t req, fuse_ino_t nodeid, req->ctx.umask = arg->umask; + if (secctx_enabled) { + err = parse_secctx_fill_req(req, iter); + if (err) { + fuse_reply_err(req, err); + return; + } + } + if (req->se->op.mkdir) { req->se->op.mkdir(req, nodeid, name, arg->mode); } else { @@ -969,12 +1039,22 @@ static void do_symlink(fuse_req_t req, fuse_ino_t nodeid, { const char *name = fuse_mbuf_iter_advance_str(iter); const char *linkname = fuse_mbuf_iter_advance_str(iter); + bool secctx_enabled = req->se->conn.want & FUSE_CAP_SECURITY_CTX; + int err; if (!name || !linkname) { fuse_reply_err(req, EINVAL); return; } + if (secctx_enabled) { + err = parse_secctx_fill_req(req, iter); + if (err) { + fuse_reply_err(req, err); + return; + } + } + if (req->se->op.symlink) { req->se->op.symlink(req, linkname, nodeid, name); } else { @@ -1048,6 +1128,8 @@ static void do_link(fuse_req_t req, fuse_ino_t nodeid, static void do_create(fuse_req_t req, fuse_ino_t nodeid, struct fuse_mbuf_iter *iter) { + bool secctx_enabled = req->se->conn.want & FUSE_CAP_SECURITY_CTX; + if (req->se->op.create) { struct fuse_create_in *arg; struct fuse_file_info fi; @@ -1060,6 +1142,15 @@ static void do_create(fuse_req_t req, fuse_ino_t nodeid, return; } + if (secctx_enabled) { + int err; + err = parse_secctx_fill_req(req, iter); + if (err) { + fuse_reply_err(req, err); + return; + } + } + memset(&fi, 0, sizeof(fi)); fi.flags = arg->flags; fi.kill_priv = arg->open_flags & FUSE_OPEN_KILL_SUIDGID; @@ -2015,6 +2106,9 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid, if (flags & FUSE_SETXATTR_EXT) { se->conn.capable |= FUSE_CAP_SETXATTR_EXT; } + if (flags & FUSE_SECURITY_CTX) { + se->conn.capable |= FUSE_CAP_SECURITY_CTX; + } #ifdef HAVE_SPLICE #ifdef HAVE_VMSPLICE se->conn.capable |= FUSE_CAP_SPLICE_WRITE | FUSE_CAP_SPLICE_MOVE; @@ -2154,8 +2248,14 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid, outarg.flags |= FUSE_SETXATTR_EXT; } + if (se->conn.want & FUSE_CAP_SECURITY_CTX) { + /* bits 32..63 get shifted down 32 bits into the flags2 field */ + outarg.flags2 |= FUSE_SECURITY_CTX >> 32; + } + fuse_log(FUSE_LOG_DEBUG, " INIT: %u.%u\n", outarg.major, outarg.minor); - fuse_log(FUSE_LOG_DEBUG, " flags=0x%08x\n", outarg.flags); + fuse_log(FUSE_LOG_DEBUG, " flags2=0x%08x flags=0x%08x\n", outarg.flags2, + outarg.flags); fuse_log(FUSE_LOG_DEBUG, " max_readahead=0x%08x\n", outarg.max_readahead); fuse_log(FUSE_LOG_DEBUG, " max_write=0x%08x\n", outarg.max_write); fuse_log(FUSE_LOG_DEBUG, " max_background=%i\n", outarg.max_background); -- 2.35.1