X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=utils%2Fstatd%2Fsm-notify.c;h=b7a5dd50b0e880c4a4b1d391c748e57c647bb5e3;hp=aa2c7d199b59c67b48839050c17f2eafd90aefc8;hb=7829fe89c152888f737dfd0e05850bc28671991d;hpb=235f44178d3412193b2b76c3be510918b67c6d95

diff --git a/utils/statd/sm-notify.c b/utils/statd/sm-notify.c
index aa2c7d1..b7a5dd5 100644
--- a/utils/statd/sm-notify.c
+++ b/utils/statd/sm-notify.c
@@ -22,9 +22,14 @@
 #include <stdarg.h>
 #include <netdb.h>
 #include <errno.h>
+#include <grp.h>
 
 #ifndef BASEDIR
-#define BASEDIR		"/var/lib/nfs"
+# ifdef NFS_STATEDIR
+#  define BASEDIR		NFS_STATEDIR
+# else
+#  define BASEDIR		"/var/lib/nfs"
+# endif
 #endif
 
 #define DEFAULT_SM_STATE_PATH	BASEDIR "/state"
@@ -80,6 +85,8 @@ static int		addr_get_port(nsm_address *);
 static void		addr_set_port(nsm_address *, int);
 static int		host_lookup(int, const char *, nsm_address *);
 void			nsm_log(int fac, const char *fmt, ...);
+static int		record_pid();
+static void		drop_privs(void);
 
 static struct nsm_host *	hosts = NULL;
 
@@ -87,9 +94,13 @@ int
 main(int argc, char **argv)
 {
 	int	c;
+	int	force = 0;
 
-	while ((c = getopt(argc, argv, "dm:np:v:qP:")) != -1) {
+	while ((c = getopt(argc, argv, "dm:np:v:qP:f")) != -1) {
 		switch (c) {
+		case 'f':
+			force = 1;
+			break;
 		case 'd':
 			opt_debug++;
 			break;
@@ -131,10 +142,18 @@ main(int argc, char **argv)
 	}
 
 	if (optind < argc) {
-usage:		fprintf(stderr, "sm-notify [-d]\n");
+usage:		fprintf(stderr,
+			"Usage: sm-notify [-dfq] [-m max-retry-minutes] [-p srcport]\n"
+			"            [-P /path/to/state/directory] [-N my_host_name\n");
 		return 1;
 	}
 
+	if (strcmp(_SM_BASE_PATH, BASEDIR) == 0) {
+		if (record_pid() == 0 && force == 0 && opt_update_state == 0)
+			/* already run, don't try again */
+			exit(0);
+	}
+
 	if (opt_srcaddr) {
 		strncpy(nsm_hostname, opt_srcaddr, sizeof(nsm_hostname)-1);
 	} else
@@ -230,6 +249,8 @@ notify(void)
 	if (opt_max_retry)
 		failtime = time(NULL) + opt_max_retry;
 
+	drop_privs();
+
 	while (hosts) {
 		struct pollfd	pfd;
 		time_t		now = time(NULL);
@@ -678,3 +699,51 @@ nsm_log(int fac, const char *fmt, ...)
 	}
 	va_end(ap);
 }
+
+/*
+ * Record pid in /var/run/sm-notify.pid
+ * This file should remain until a reboot, even if the
+ * program exits.
+ * If file already exists, fail.
+ */
+static int record_pid()
+{
+	char pid[20];
+	int fd;
+
+	snprintf(pid, 20, "%d\n", getpid());
+	fd = open("/var/run/sm-notify.pid", O_CREAT|O_EXCL|O_WRONLY, 0600);
+	if (!fd)
+		return 0;
+	write(fd, pid, strlen(pid));
+	close(fd);
+	return 1;
+}
+
+/* Drop privileges to match owner of state-directory
+ * (in case a reply triggers some unknown bug).
+ */
+static void drop_privs(void)
+{
+	struct stat st;
+
+	if (stat(_SM_DIR_PATH, &st) == -1 &&
+	    stat(_SM_BASE_PATH, &st) == -1) {
+		st.st_uid = 0;
+		st.st_gid = 0;
+	}
+
+	if (st.st_uid == 0) {
+		nsm_log(LOG_WARNING,
+			"sm-notify running as root. chown %s to choose different user\n",
+		    _SM_DIR_PATH);
+		return;
+	}
+
+	setgroups(0, NULL);
+	if (setgid(st.st_gid) == -1
+	    || setuid(st.st_uid) == -1) {
+		nsm_log(LOG_ERR, "Fail to drop privileges");
+		exit(1);
+	}
+}