From 4f088dbf98aecde6eed94d630964cc36cd39837b Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Fri, 23 Oct 2020 17:58:09 +0100 Subject: [PATCH] tools/virtiofsd: xattr name mappings: Map client xattr names Map xattr names originating at the client; from get/set/remove xattr. Signed-off-by: Dr. David Alan Gilbert Message-Id: <20201023165812.36028-3-dgilbert@redhat.com> Reviewed-by: Stefan Hajnoczi Signed-off-by: Dr. David Alan Gilbert --- tools/virtiofsd/passthrough_ll.c | 101 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 98 insertions(+), 3 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index cb24af27f5..cf67737751 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -2188,20 +2188,80 @@ static void parse_xattrmap(struct lo_data *lo) } } -static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *name, +/* + * For use with getxattr/setxattr/removexattr, where the client + * gives us a name and we may need to choose a different one. + * Allocates a buffer for the result placing it in *out_name. + * If there's no change then *out_name is not set. + * Returns 0 on success + * Can return -EPERM to indicate we block a given attribute + * (in which case out_name is not allocated) + * Can return -ENOMEM to indicate out_name couldn't be allocated. + */ +static int xattr_map_client(const struct lo_data *lo, const char *client_name, + char **out_name) +{ + size_t i; + for (i = 0; i < lo->xattr_map_nentries; i++) { + const XattrMapEntry *cur_entry = lo->xattr_map_list + i; + + if ((cur_entry->flags & XATTR_MAP_FLAG_CLIENT) && + (strstart(client_name, cur_entry->key, NULL))) { + if (cur_entry->flags & XATTR_MAP_FLAG_BAD) { + return -EPERM; + } + if (cur_entry->flags & XATTR_MAP_FLAG_OK) { + /* Unmodified name */ + return 0; + } + if (cur_entry->flags & XATTR_MAP_FLAG_PREFIX) { + *out_name = g_try_malloc(strlen(client_name) + + strlen(cur_entry->prepend) + 1); + if (!*out_name) { + return -ENOMEM; + } + sprintf(*out_name, "%s%s", cur_entry->prepend, client_name); + return 0; + } + } + } + + return -EPERM; +} + +static void lo_getxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, size_t size) { struct lo_data *lo = lo_data(req); char *value = NULL; char procname[64]; + const char *name; + char *mapped_name; struct lo_inode *inode; ssize_t ret; int saverr; int fd = -1; + mapped_name = NULL; + name = in_name; + if (lo->xattrmap) { + ret = xattr_map_client(lo, in_name, &mapped_name); + if (ret < 0) { + if (ret == -EPERM) { + ret = -ENODATA; + } + fuse_reply_err(req, -ret); + return; + } + if (mapped_name) { + name = mapped_name; + } + } + inode = lo_inode(req, ino); if (!inode) { fuse_reply_err(req, EBADF); + g_free(mapped_name); return; } @@ -2266,6 +2326,7 @@ out_err: saverr = errno; out: fuse_reply_err(req, saverr); + g_free(mapped_name); goto out_free; } @@ -2343,19 +2404,35 @@ out: goto out_free; } -static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *name, +static void lo_setxattr(fuse_req_t req, fuse_ino_t ino, const char *in_name, const char *value, size_t size, int flags) { char procname[64]; + const char *name; + char *mapped_name; struct lo_data *lo = lo_data(req); struct lo_inode *inode; ssize_t ret; int saverr; int fd = -1; + mapped_name = NULL; + name = in_name; + if (lo->xattrmap) { + ret = xattr_map_client(lo, in_name, &mapped_name); + if (ret < 0) { + fuse_reply_err(req, -ret); + return; + } + if (mapped_name) { + name = mapped_name; + } + } + inode = lo_inode(req, ino); if (!inode) { fuse_reply_err(req, EBADF); + g_free(mapped_name); return; } @@ -2390,21 +2467,38 @@ out: } lo_inode_put(lo, &inode); + g_free(mapped_name); fuse_reply_err(req, saverr); } -static void lo_removexattr(fuse_req_t req, fuse_ino_t ino, const char *name) +static void lo_removexattr(fuse_req_t req, fuse_ino_t ino, const char *in_name) { char procname[64]; + const char *name; + char *mapped_name; struct lo_data *lo = lo_data(req); struct lo_inode *inode; ssize_t ret; int saverr; int fd = -1; + mapped_name = NULL; + name = in_name; + if (lo->xattrmap) { + ret = xattr_map_client(lo, in_name, &mapped_name); + if (ret < 0) { + fuse_reply_err(req, -ret); + return; + } + if (mapped_name) { + name = mapped_name; + } + } + inode = lo_inode(req, ino); if (!inode) { fuse_reply_err(req, EBADF); + g_free(mapped_name); return; } @@ -2439,6 +2533,7 @@ out: } lo_inode_put(lo, &inode); + g_free(mapped_name); fuse_reply_err(req, saverr); } -- 2.11.4.GIT