From 5425a217555f03f6c0aa8af371e0f7262b994a0d Mon Sep 17 00:00:00 2001
From: Quentin Young <qlyoung@cumulusnetworks.com>
Date: Thu, 2 Jan 2020 02:01:57 -0500
Subject: [PATCH] lib: improve frr_init_fast() speeeed

Aggressively disable some more things.

This also disables privilege dropping, because it breaks AFL deferred
mode. After this patch we can run about 10-20x faster with deferred
mode!

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>
---
 lib/libfrr.c | 24 ++++++------------------
 lib/privs.c  | 14 ++++++++++++++
 2 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/lib/libfrr.c b/lib/libfrr.c
index bcbba42fc7..9409fac9f2 100644
--- a/lib/libfrr.c
+++ b/lib/libfrr.c
@@ -785,6 +785,7 @@ struct thread_master *frr_init(void)
 	return master;
 }
 
+#ifdef FUZZING
 static struct thread_master *master;
 struct thread_master *frr_init_fast(void)
 {
@@ -795,30 +796,12 @@ struct thread_master *frr_init_fast(void)
 	const char *dir;
 	dir = di->module_path ? di->module_path : frr_moduledir;
 #endif
-	char p_instance[16] = "", p_pathspace[256] = "";
-
-	srandom(time(NULL));
-
-	if (di->instance) {
-		snprintf(frr_protonameinst, sizeof(frr_protonameinst), "%s[%u]",
-			 di->logname, di->instance);
-		snprintf(p_instance, sizeof(p_instance), "-%d", di->instance);
-	}
-	if (di->pathspace)
-		snprintf(p_pathspace, sizeof(p_pathspace), "%s/",
-			 di->pathspace);
-
-	snprintf(config_default, sizeof(config_default), "%s%s%s%s.conf",
-		 frr_sysconfdir, p_pathspace, di->name, p_instance);
-	snprintf(pidfile_default, sizeof(pidfile_default), "%s/%s%s.pid",
-		 frr_vtydir, di->name, p_instance);
 #if 0
 #ifdef HAVE_SQLITE3
 	snprintf(dbfile_default, sizeof(dbfile_default), "%s/%s%s%s.db",
 		 frr_dbdir, p_pathspace, di->name, p_instance);
 #endif
 #endif
-
 	zprivs_preinit(di->privs);
 
 	openzlog(di->progname, di->logname, di->instance,
@@ -826,6 +809,7 @@ struct thread_master *frr_init_fast(void)
 
 	command_setup_early_logging(di->early_logging, di->early_loglevel);
 
+#if 0
 	if (!frr_zclient_addr(&zclient_addr, &zclient_addr_len,
 			      frr_zclientpath)) {
 		fprintf(stderr, "Invalid zserv socket path: %s\n",
@@ -842,6 +826,7 @@ struct thread_master *frr_init_fast(void)
 		if (di->vty_path)
 			frr_mkdir(di->vty_path, true);
 	}
+#endif
 
 #if 0
 	frrmod_init(di->module);
@@ -885,7 +870,9 @@ struct thread_master *frr_init_fast(void)
 #endif
 
 	log_ref_init();
+#if 0
 	log_ref_vty_init();
+#endif
 	lib_error_init();
 
 #if 0
@@ -902,6 +889,7 @@ struct thread_master *frr_init_fast(void)
 
 	return master;
 }
+#endif
 
 const char *frr_get_progname(void)
 {
diff --git a/lib/privs.c b/lib/privs.c
index b3f51267d1..6bc9ba4534 100644
--- a/lib/privs.c
+++ b/lib/privs.c
@@ -273,6 +273,7 @@ static void zprivs_caps_init(struct zebra_privs_t *zprivs)
 	/* we have caps, we have no need to ever change back the original user
 	 */
 	/* only change uid if we don't have the correct one */
+#ifndef FUZZING
 	if ((zprivs_state.zuid) && (zprivs_state.zsuid != zprivs_state.zuid)) {
 		if (setreuid(zprivs_state.zuid, zprivs_state.zuid)) {
 			fprintf(stderr,
@@ -281,6 +282,7 @@ static void zprivs_caps_init(struct zebra_privs_t *zprivs)
 			exit(1);
 		}
 	}
+#endif
 
 	if (!zprivs_state.syscaps_p)
 		return;
@@ -312,6 +314,7 @@ static void zprivs_caps_init(struct zebra_privs_t *zprivs)
 	/* apply caps. CAP_EFFECTIVE is cleared. we'll raise the caps as
 	 * and when, and only when, they are needed.
 	 */
+#ifndef FUZZING
 	if (cap_set_proc(zprivs_state.caps)) {
 		cap_t current_caps;
 		char *current_caps_text = NULL;
@@ -338,6 +341,7 @@ static void zprivs_caps_init(struct zebra_privs_t *zprivs)
 
 		exit(1);
 	}
+#endif
 
 	/* set methods for the caller to use */
 	zprivs->change = zprivs_change_caps;
@@ -475,6 +479,9 @@ static struct zebra_privs_refs_t *get_privs_refs(struct zebra_privs_t *privs)
 struct zebra_privs_t *_zprivs_raise(struct zebra_privs_t *privs,
 				    const char *funcname)
 {
+#ifdef FUZZING
+	return NULL;
+#endif
 	int save_errno = errno;
 	struct zebra_privs_refs_t *refs;
 
@@ -505,6 +512,9 @@ struct zebra_privs_t *_zprivs_raise(struct zebra_privs_t *privs,
 
 void _zprivs_lower(struct zebra_privs_t **privs)
 {
+#ifdef FUZZING
+	return;
+#endif
 	int save_errno = errno;
 	struct zebra_privs_refs_t *refs;
 
@@ -649,6 +659,7 @@ void zprivs_init(struct zebra_privs_t *zprivs)
 
 	zprivs_state.zsuid = geteuid(); /* initial uid */
 	/* add groups only if we changed uid - otherwise skip */
+#ifndef FUZZING
 	if ((ngroups) && (zprivs_state.zsuid != zprivs_state.zuid)) {
 		if (setgroups(ngroups, groups)) {
 			fprintf(stderr, "privs_init: could not setgroups, %s\n",
@@ -666,6 +677,7 @@ void zprivs_init(struct zebra_privs_t *zprivs)
 			exit(1);
 		}
 	}
+#endif
 
 #ifdef HAVE_CAPABILITIES
 	zprivs_caps_init(zprivs);
@@ -691,6 +703,7 @@ void zprivs_init(struct zebra_privs_t *zprivs)
 	 */
 	zprivs_state.zsuid = geteuid();
 	/* only change uid if we don't have the correct one */
+#ifndef FUZZING
 	if ((zprivs_state.zuid) && (zprivs_state.zsuid != zprivs_state.zuid)) {
 		if (setreuid(-1, zprivs_state.zuid)) {
 			fprintf(stderr,
@@ -702,6 +715,7 @@ void zprivs_init(struct zebra_privs_t *zprivs)
 
 	zprivs->change = zprivs_change_uid;
 	zprivs->current_state = zprivs_state_uid;
+#endif
 #endif /* HAVE_CAPABILITIES */
 }
 
-- 
2.39.5