From: Omar Polo <op@omarpolo.com>
Subject: gotwebd: set chroot once and use it
To: gameoftrees@openbsd.org
Date: Thu, 15 Jun 2023 13:20:06 +0200

continuing the strlen() quest brought me here.  We have a lot of
strlen(env->httpd_chroot) ? env->httpd_chroot : D_HTTPD_CHROOT that
I'd like to get rid of.  I made parse.y strictier in that `chroot ""`
is now rejected, so that we can fill the default chroot path in
config_init(), optionally update in parse.y, and we're done.

sockets_run() in sockets.c will reset the chroot path since it calls
config_init() again but it's not an issue since reached that stage we
don't care anymore about the chroot path.  I'll address it in a future
commit anyway however since I'd prefer if we call config_init() only
once.

ok?

diff /home/op/w/got
commit - 23c35dae297d2eecd13e17118a547761314a578d
path + /home/op/w/got
blob - a6a1722df89866f0ad5a9adb12cf2820cd9831bb
file + gotwebd/config.c
--- gotwebd/config.c
+++ gotwebd/config.c
@@ -48,6 +48,8 @@ config_init(struct gotwebd *env)
 	struct privsep *ps = env->gotwebd_ps;
 	unsigned int what;
 
+	strlcpy(env->httpd_chroot, D_HTTPD_CHROOT, sizeof(env->httpd_chroot));
+
 	/* Global configuration. */
 	if (privsep_process == PROC_GOTWEBD)
 		env->prefork_gotwebd = GOTWEBD_NUMPROC;
blob - 3633c55f9eed4080f24d13cadb5b1fb99b89cf9c
file + gotwebd/gotwebd.c
--- gotwebd/gotwebd.c
+++ gotwebd/gotwebd.c
@@ -213,8 +213,7 @@ main(int argc, char **argv)
 		ps->ps_title[proc_id] = title;
 
 	for (proc = 0; proc < nitems(procs); proc++)
-		procs[proc].p_chroot = strlen(env->httpd_chroot) ?
-		    env->httpd_chroot : D_HTTPD_CHROOT;
+		procs[proc].p_chroot = env->httpd_chroot;
 
 	/* only the gotwebd returns */
 	proc_init(ps, procs, nitems(procs), argc0, argv, proc_id);
@@ -251,8 +250,7 @@ main(int argc, char **argv)
 		err(1, "gmon.out");
 #endif
 
-	if (unveil(strlen(env->httpd_chroot) > 0 ? env->httpd_chroot :
-	    D_HTTPD_CHROOT, "rwc") == -1)
+	if (unveil(env->httpd_chroot, "rwc") == -1)
 		err(1, "unveil");
 
 	if (unveil(GOT_TMPDIR_STR, "rw") == -1)
blob - a20548a36dab44bcdc56af91c0847fc938ea5df6
file + gotwebd/parse.y
--- gotwebd/parse.y
+++ gotwebd/parse.y
@@ -231,8 +231,7 @@ main		: PREFORK NUMBER {
 		| UNIX_SOCKET_NAME STRING {
 			n = snprintf(gotwebd->unix_socket_name,
 			    sizeof(gotwebd->unix_socket_name), "%s%s",
-			    strlen(gotwebd->httpd_chroot) ?
-			    gotwebd->httpd_chroot : D_HTTPD_CHROOT, $2);
+			    gotwebd->httpd_chroot, $2);
 			if (n < 0 ||
 			    (size_t)n >= sizeof(gotwebd->unix_socket_name)) {
 				yyerror("%s: unix_socket_name truncated",
@@ -364,8 +363,7 @@ serveropts1	: REPOS_PATH STRING {
 
 			n = snprintf(new_srv->unix_socket_name,
 			    sizeof(new_srv->unix_socket_name), "%s%s",
-			    strlen(gotwebd->httpd_chroot) ?
-			    gotwebd->httpd_chroot : D_HTTPD_CHROOT, $4);
+			    gotwebd->httpd_chroot, $4);
 			if (n < 0 ||
 			    (size_t)n >= sizeof(new_srv->unix_socket_name)) {
 				yyerror("%s: unix_socket_name truncated",