X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=utils%2Fmountd%2Frmtab.c;h=844de511f48b07d76baac5b0b828b9e5520af33f;hp=289a42e2b95fe0a0089ea71b7c65a0e010e60637;hb=18fc7a86a2a1213762cc4107565903127efadafc;hpb=8b7ad01b14df1e7529b9ba8a1ea17df0d6004ef9

diff --git a/utils/mountd/rmtab.c b/utils/mountd/rmtab.c
index 289a42e..844de51 100644
--- a/utils/mountd/rmtab.c
+++ b/utils/mountd/rmtab.c
@@ -8,7 +8,9 @@
 
 #include "config.h"
 
+#include <sys/types.h>
 #include <sys/stat.h>
+#include <unistd.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <netdb.h>
@@ -18,45 +20,74 @@
 #include "xio.h"
 #include "mountd.h"
 
+#include <limits.h> /* PATH_MAX */
+
+/* If new path is a link do not destroy it but place the
+ * file where the link points.
+ */
+
+static int 
+slink_safe_rename(const char * oldpath, const char * newpath)
+{
+	int r;
+	struct stat s;
+	char slink_path[PATH_MAX];
+	const char *real_newpath = newpath;
+
+	if ((lstat(newpath, &s) == 0) && S_ISLNK(s.st_mode)) {
+		/* New path is a symbolic link, do not destroy but follow */
+		if ((r = readlink(newpath, slink_path, PATH_MAX - 1)) == -1)
+			return -1;
+		slink_path[r] = '\0';
+		real_newpath = slink_path;
+	}
+
+	return rename(oldpath, real_newpath);
+}
+
 void
-mountlist_add(nfs_export *exp, const char *path)
+mountlist_add(char *host, const char *path)
 {
 	struct rmtabent	xe;
 	struct rmtabent	*rep;
 	int		lockid;
+	long		pos;
 
 	if ((lockid = xflock(_PATH_RMTAB, "a")) < 0)
 		return;
-	setrmtabent("r");
-	while ((rep = getrmtabent(1)) != NULL) {
+	setrmtabent("r+");
+	while ((rep = getrmtabent(1, &pos)) != NULL) {
 		if (strcmp (rep->r_client,
-			    exp->m_client->m_hostname) == 0
+			    host) == 0
 		    && strcmp(rep->r_path, path) == 0) {
+			rep->r_count++;
+			putrmtabent(rep, &pos);
 			endrmtabent();
 			xfunlock(lockid);
 			return;
 		}
 	}
 	endrmtabent();
-	strncpy(xe.r_client, exp->m_client->m_hostname,
+	strncpy(xe.r_client, host,
 		sizeof (xe.r_client) - 1);
 	xe.r_client [sizeof (xe.r_client) - 1] = '\0';
 	strncpy(xe.r_path, path, sizeof (xe.r_path) - 1);
 	xe.r_path [sizeof (xe.r_path) - 1] = '\0';
+	xe.r_count = 1;
 	if (setrmtabent("a")) {
-		putrmtabent(&xe);
+		putrmtabent(&xe, NULL);
 		endrmtabent();
 	}
 	xfunlock(lockid);
 }
 
 void
-mountlist_del(nfs_export *exp, const char *path)
+mountlist_del(char *hname, const char *path)
 {
 	struct rmtabent	*rep;
 	FILE		*fp;
-	char		*hname = exp->m_client->m_hostname;
 	int		lockid;
+	int		match;
 
 	if ((lockid = xflock(_PATH_RMTAB, "w")) < 0)
 		return;
@@ -69,12 +100,15 @@ mountlist_del(nfs_export *exp, const char *path)
 		xfunlock(lockid);
 		return;
 	}
-	while ((rep = getrmtabent(1)) != NULL) {
-		if (strcmp (rep->r_client, hname)
-		    || strcmp(rep->r_path, path))
-			fputrmtabent(fp, rep);
+	while ((rep = getrmtabent(1, NULL)) != NULL) {
+		match = !strcmp (rep->r_client, hname)
+			&& !strcmp(rep->r_path, path);
+		if (match)
+			rep->r_count--;
+		if (!match || rep->r_count)
+			fputrmtabent(fp, rep, NULL);
 	}
-	if (rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
+	if (slink_safe_rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
 		xlog(L_ERROR, "couldn't rename %s to %s",
 				_PATH_RMTABTMP, _PATH_RMTAB);
 	}
@@ -114,15 +148,15 @@ mountlist_del_all(struct sockaddr_in *sin)
 		free (hp);
 		return;
 	}
-	while ((rep = getrmtabent(1)) != NULL) {
+	while ((rep = getrmtabent(1, NULL)) != NULL) {
 		if (strcmp(rep->r_client, hp->h_name) == 0 &&
 		    (exp = auth_authenticate("umountall", sin, rep->r_path))) {
 			export_reset(exp);
 			continue;
 		}
-		fputrmtabent(fp, rep);
+		fputrmtabent(fp, rep, NULL);
 	}
-	if (rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
+	if (slink_safe_rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
 		xlog(L_ERROR, "couldn't rename %s to %s",
 				_PATH_RMTABTMP, _PATH_RMTAB);
 	}
@@ -158,7 +192,7 @@ mountlist_list(void)
 		last_mtime = stb.st_mtime;
 
 		setrmtabent("r");
-		while ((rep = getrmtabent(1)) != NULL) {
+		while ((rep = getrmtabent(1, NULL)) != NULL) {
 			m = (mountlist) xmalloc(sizeof(*m));
 			m->ml_hostname = xstrdup(rep->r_client);
 			m->ml_directory = xstrdup(rep->r_path);