Changes and cleanups around the privileged user.

Ticket:  CM-19457
Reviewed By: nobody
Testing Done:  lots of logins, and login combinations

Validate that the mapuser database files are valid by using kill 0 on
the pids.  If not valid, try to unlink, and if we do, report it as a
DEBUG.  If we can't unlink (not root) report that we are skipping at INFO.

As part of that, don't count valid fields and read entire file.

Document in man page and config file that the mapped_priv_user account
is known to libpam-radius-auth as well, and must be updated in both
places if it changes.

Updated the public symbols (the getgr additions) from previous commit

Fixed some white space and line length issues.

1 files changed, 36 insertions, 17 deletions

diff --git a/map_common.c b/map_common.c
index 830d85a..b6fe3bc 100644
--- a/map_common.c
+++ b/map_common.c
@@ -26,6 +26,7 @@
 #include "map_common.h"
 #include <sys/stat.h>
 #include <stddef.h>
+#include <signal.h>
 #include <fcntl.h>
 #include <dirent.h>
 #include <ctype.h>
@@ -293,7 +294,7 @@ get_pw_mapuser(const char *name, struct pwbuf *pb, uid_t mapuid, int privileged)
 	for (ret = 1; ret && (ent = fgetpwent(pwfile));) {
 		if (!ent->pw_name)
 			continue;	/* shouldn't happen */
-		if (!strcmp(ent->pw_name, name) ||
+		if (!strcmp(ent->pw_name, name) || /*  added locally */
 		    !strcmp(ent->pw_name, privileged ? mapped_priv_user :
 			    mappeduser) || ent->pw_uid == mapuid) {
 			ret =
@@ -320,7 +321,6 @@ static int chk_session_file(char *session, uid_t uid, struct pwbuf *pb)
 	FILE *mapf;
 	uid_t auid = 0;
 	int ret = 1, privileged = 0;;
-	int gotinfo = 0;	/*  user, session, auid */
 
 	snprintf(sessfile, sizeof sessfile, "%s%s", dbdir, session);
 
@@ -333,46 +333,65 @@ static int chk_session_file(char *session, uid_t uid, struct pwbuf *pb)
 		return ret;
 	}
 	user[0] = '\0';
-	while (gotinfo != 4 && fgets(rbuf, sizeof rbuf, mapf)) {
-		strtok(rbuf, " \t\n\r\f");	/* terminate buffer at first whitespace */
+	while (fgets(rbuf, sizeof rbuf, mapf)) {
+		/* terminate buffer at first whitespace */
+		strtok(rbuf, " \t\n\r\f");
 		if (!strncmp("user=", rbuf, 5)) {
 			if (pb->name && strcmp(rbuf + 5, pb->name))
 				break;
 			snprintf(user, sizeof user, "%s", rbuf + 5);
-			gotinfo++;
+		} else if (!strncmp("pid=", rbuf, 4)) {
+			char *ok;
+			unsigned pid = (unsigned) strtoul(rbuf + 4, &ok, 10);
+			if (ok != (rbuf + 4) && pid > 0 && kill(pid, 0) &&
+			    errno == ESRCH) {
+				/*  ESRCH instead of any error because perms as
+				 *  non-root.  Try to unlink, since we often
+				 *  run as root; report as DEBUG if we unlink,
+				 *  report as INFO if not */
+				if (unlink(sessfile) == 0)
+					syslog(LOG_DEBUG, "session file %s"
+					       " PID=%u no longer active,"
+					       " removed", sessfile, pid);
+				else
+					syslog(LOG_INFO, "session file %s"
+					       " PID=%u no longer active, skip",
+					       sessfile, pid);
+				auid = 0; /*  force fail */
+				break;
+			}
 		} else if (!strncmp("auid=", rbuf, 5)) {
 			char *ok;
 			uid_t fuid = (uid_t) strtoul(rbuf + 5, &ok, 10);
 			if (ok != (rbuf + 5)) {
-				gotinfo++;
 				if (uid != -1 && fuid != uid) {
-					auid = fuid;
-					break;	/*  getpwuid, but uid/auid mismatch, nogo */
+					/*  getpwuid call but mismatch, nogo */
+					break;
 				} else
 					auid = fuid;
 			}
 		} else if (!strcasecmp("privileged=yes", rbuf)) {
 			privileged = 1;
-			gotinfo++;
-		} else if (!strcasecmp("privileged=no", rbuf))
-			gotinfo++;
-		else if (!strncmp("session=", rbuf, 8)) {
+		} else if (!strcasecmp("privileged=no", rbuf)) {
+			privileged = 0;
+		} else if (!strncmp("session=", rbuf, 8)) {
 			/*  structural problem, so log warning */
 			if (strcmp(session, rbuf + 8)) {
 				syslog(LOG_WARNING,
-				       "%s: session field \"%s\" mismatch in %s",
+				       "%s: session \"%s\" mismatch in %s",
 				       libname, rbuf, sessfile);
-			} else
-				gotinfo++;
+				auid = 0; /*  force a skip */
+			}
 		}
 	}
 	fclose(mapf);
 
-	if (auid && user[0]) {	/*  otherwise not a match */
+	if (auid && (uid == (uid_t)-1 || auid == uid) && user[0]) {
 		if (!pb->name)
 			pb->name = user;	/*  uid lookups */
 		ret = get_pw_mapuser(user, pb, auid, privileged);
 	}
+	/*  otherwise not a match */
 
 	return ret;
 }
@@ -429,7 +448,7 @@ int find_mappingfile(struct pwbuf *pb, uid_t uid)
 int make_mapuser(struct pwbuf *pb, const char *name)
 {
 	int ret;
-	ret = get_pw_mapuser(mappeduser, pb, (uid_t) - 1, 0);
+	ret = get_pw_mapuser(mappeduser, pb, (uid_t)-1, 0);
 	return ret;
 }