Add helper functions that can resolve nfsd paths by prepending the
necessary prefix if the admin has specified a root path in the
nfs.conf file.
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
configure.ac | 2 +-
support/include/Makefile.am | 2 +
support/include/nfsd_path.h | 16 ++++
support/include/xstat.h | 11 +++
support/misc/Makefile.am | 3 +-
support/misc/nfsd_path.c | 168 ++++++++++++++++++++++++++++++++++++
support/misc/xstat.c | 33 +++++++
7 files changed, 233 insertions(+), 2 deletions(-)
create mode 100644 support/include/nfsd_path.h
create mode 100644 support/include/xstat.h
create mode 100644 support/misc/nfsd_path.c
create mode 100644 support/misc/xstat.c
diff --git a/configure.ac b/configure.ac
index c6c2d73b06dd..e870862a8abb 100644
--- a/configure.ac
+++ b/configure.ac
@@ -321,7 +321,7 @@ AC_CHECK_FUNC([getservbyname], ,
AC_CHECK_LIB([crypt], [crypt], [LIBCRYPT="-lcrypt"])
AC_CHECK_HEADERS([sched.h], [], [])
-AC_CHECK_FUNCS([unshare], [] , [])
+AC_CHECK_FUNCS([unshare fstatat], [] , [])
AC_LIBPTHREAD([])
if test "$enable_nfsv4" = yes; then
diff --git a/support/include/Makefile.am b/support/include/Makefile.am
index df5e47836d29..1373891a7c76 100644
--- a/support/include/Makefile.am
+++ b/support/include/Makefile.am
@@ -10,6 +10,7 @@ noinst_HEADERS = \
misc.h \
nfs_mntent.h \
nfs_paths.h \
+ nfsd_path.h \
nfslib.h \
nfsrpc.h \
nls.h \
@@ -24,6 +25,7 @@ noinst_HEADERS = \
xlog.h \
xmalloc.h \
xcommon.h \
+ xstat.h \
conffile.h
MAINTAINERCLEANFILES = Makefile.in
diff --git a/support/include/nfsd_path.h b/support/include/nfsd_path.h
new file mode 100644
index 000000000000..db9b41a179ad
--- /dev/null
+++ b/support/include/nfsd_path.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) 2019 Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
+ */
+#ifndef NFSD_PATH_H
+#define NFSD_PATH_H
+
+void nfsd_path_init(void);
+
+const char * nfsd_path_nfsd_rootdir(void);
+char * nfsd_path_strip_root(char *pathname);
+char * nfsd_path_prepend_dir(const char *dir, const char *pathname);
+
+int nfsd_path_stat(const char *pathname, struct stat *statbuf);
+int nfsd_path_lstat(const char *pathname, struct stat *statbuf);
+
+#endif
diff --git a/support/include/xstat.h b/support/include/xstat.h
new file mode 100644
index 000000000000..f1241bbfdc0e
--- /dev/null
+++ b/support/include/xstat.h
@@ -0,0 +1,11 @@
+/*
+ * Copyright (C) 2019 Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
+ */
+#ifndef XSTAT_H
+#define XSTAT_H
+
+struct stat;
+
+int xlstat(const char *pathname, struct stat *statbuf);
+int xstat(const char *pathname, struct stat *statbuf);
+#endif
diff --git a/support/misc/Makefile.am b/support/misc/Makefile.am
index d0bff8feb6ae..f9993e3ac897 100644
--- a/support/misc/Makefile.am
+++ b/support/misc/Makefile.am
@@ -1,6 +1,7 @@
## Process this file with automake to produce Makefile.in
noinst_LIBRARIES = libmisc.a
-libmisc_a_SOURCES = tcpwrapper.c from_local.c mountpoint.c file.c workqueue.c
+libmisc_a_SOURCES = tcpwrapper.c from_local.c mountpoint.c file.c \
+ nfsd_path.c workqueue.c xstat.c
MAINTAINERCLEANFILES = Makefile.in
diff --git a/support/misc/nfsd_path.c b/support/misc/nfsd_path.c
new file mode 100644
index 000000000000..fe2c011b1521
--- /dev/null
+++ b/support/misc/nfsd_path.c
@@ -0,0 +1,168 @@
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "config.h"
+#include "conffile.h"
+#include "xmalloc.h"
+#include "xlog.h"
+#include "xstat.h"
+#include "nfsd_path.h"
+#include "workqueue.h"
+
+static struct xthread_workqueue *nfsd_wq;
+
+static int
+nfsd_path_isslash(const char *path)
+{
+ return path[0] == '/' && path[1] == '/';
+}
+
+static int
+nfsd_path_isdot(const char *path)
+{
+ return path[0] == '.' && path[1] == '/';
+}
+
+static const char *
+nfsd_path_strip(const char *path)
+{
+ if (!path || *path == '\0')
+ goto out;
+ for (;;) {
+ if (nfsd_path_isslash(path)) {
+ path++;
+ continue;
+ }
+ if (nfsd_path_isdot(path)) {
+ path += 2;
+ continue;
+ }
+ break;
+ }
+out:
+ return path;
+}
+
+const char *
+nfsd_path_nfsd_rootdir(void)
+{
+ const char *rootdir;
+
+ rootdir = nfsd_path_strip(conf_get_str("exports", "rootdir"));
+ if (!rootdir || rootdir[0] == '\0')
+ return NULL;
+ if (rootdir[0] == '/' && rootdir[1] == '\0')
+ return NULL;
+ return rootdir;
+}
+
+char *
+nfsd_path_strip_root(char *pathname)
+{
+ const char *dir = nfsd_path_nfsd_rootdir();
+ char *ret;
+
+ ret = strstr(pathname, dir);
+ if (!ret || ret != pathname)
+ return pathname;
+ return pathname + strlen(dir);
+}
+
+char *
+nfsd_path_prepend_dir(const char *dir, const char *pathname)
+{
+ size_t len, dirlen;
+ char *ret;
+
+ dirlen = strlen(dir);
+ while (dirlen > 0 && dir[dirlen - 1] == '/')
+ dirlen--;
+ if (!dirlen)
+ return NULL;
+ len = dirlen + strlen(pathname) + 1;
+ ret = xmalloc(len + 1);
+ snprintf(ret, len, "%.*s/%s", (int)dirlen, dir, pathname);
+ return ret;
+}
+
+static void
+nfsd_setup_workqueue(void)
+{
+ const char *rootdir = nfsd_path_nfsd_rootdir();
+
+ if (!rootdir)
+ return;
+ nfsd_wq = xthread_workqueue_alloc();
+ if (!nfsd_wq)
+ return;
+ xthread_workqueue_chroot(nfsd_wq, rootdir);
+}
+
+void
+nfsd_path_init(void)
+{
+ nfsd_setup_workqueue();
+}
+
+struct nfsd_stat_data {
+ const char *pathname;
+ struct stat *statbuf;
+ int ret;
+ int err;
+};
+
+static void
+nfsd_statfunc(void *data)
+{
+ struct nfsd_stat_data *d = data;
+
+ d->ret = xstat(d->pathname, d->statbuf);
+ if (d->ret < 0)
+ d->err = errno;
+}
+
+static void
+nfsd_lstatfunc(void *data)
+{
+ struct nfsd_stat_data *d = data;
+
+ d->ret = xlstat(d->pathname, d->statbuf);
+ if (d->ret < 0)
+ d->err = errno;
+}
+
+static int
+nfsd_run_stat(struct xthread_workqueue *wq,
+ void (*func)(void *),
+ const char *pathname,
+ struct stat *statbuf)
+{
+ struct nfsd_stat_data data = {
+ pathname,
+ statbuf,
+ 0,
+ 0
+ };
+ xthread_work_run_sync(wq, func, &data);
+ if (data.ret < 0)
+ errno = data.err;
+ return data.ret;
+}
+
+int
+nfsd_path_stat(const char *pathname, struct stat *statbuf)
+{
+ if (!nfsd_wq)
+ return xstat(pathname, statbuf);
+ return nfsd_run_stat(nfsd_wq, nfsd_statfunc, pathname, statbuf);
+}
+
+int
+nfsd_path_lstat(const char *pathname, struct stat *statbuf)
+{
+ if (!nfsd_wq)
+ return xlstat(pathname, statbuf);
+ return nfsd_run_stat(nfsd_wq, nfsd_lstatfunc, pathname, statbuf);
+}
diff --git a/support/misc/xstat.c b/support/misc/xstat.c
new file mode 100644
index 000000000000..d092f73dfd65
--- /dev/null
+++ b/support/misc/xstat.c
@@ -0,0 +1,33 @@
+#include <sys/types.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "config.h"
+#include "xstat.h"
+
+#ifdef HAVE_FSTATAT
+
+int xlstat(const char *pathname, struct stat *statbuf)
+{
+ return fstatat(AT_FDCWD, pathname, statbuf, AT_NO_AUTOMOUNT |
+ AT_SYMLINK_NOFOLLOW);
+}
+
+int xstat(const char *pathname, struct stat *statbuf)
+{
+ return fstatat(AT_FDCWD, pathname, statbuf, AT_NO_AUTOMOUNT);
+}
+
+#else
+
+int xlstat(const char *pathname, struct stat *statbuf)
+{
+ return lstat(pathname, statbuf);
+}
+
+int xstat(const char *pathname, struct stat *statbuf)
+{
+ return stat(pathname, statbuf);
+}
+#endif
--
2.21.0
