From fcc0463a3eb858fe9412a88b821dfd75134046cb Mon Sep 17 00:00:00 2001
From: Dimitri Papadopoulos
 <3350651-DimitriPapadopoulos@users.noreply.gitlab.com>
Date: Tue, 25 Apr 2023 13:22:46 +0300
Subject: [PATCH] Get rid of non-reentrant functions

Because we know the code in `main.c` is executed in a single-threaded
environment, we don't need to modify non-reentant functions in this file,
unless some linter complains in the future:
* localtime()
* getpwnam()

The only remaining non-entrant function is:
* getpwuid()

Using constant 2049 instead of sysconf(_SC_GETPW_R_SIZE_MAX) might not
be the best idea. I want to avoid dynamic allocation. On Ubuntu 18.04,
sysconf(_SC_GETPW_R_SIZE_MAX) is 1024, so 2049 "ought to be enough".

Signed-off-by: Dimitri Papadopoulos <3350651-DimitriPapadopoulos@users.noreply.gitlab.com>
---
 auth.c | 13 +++++++------
 main.c |  2 +-
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/auth.c b/auth.c
index 317fc218..a449cfc0 100644
--- a/auth.c
+++ b/auth.c
@@ -1114,7 +1114,8 @@ int set_csd_user(struct openconnect_info *vpninfo)
 	setsid();
 
 	if (vpninfo->uid_csd_given && vpninfo->uid_csd != getuid()) {
-		struct passwd *pw;
+		struct passwd pwd, *result;
+		char buffer[2049]; /* should be sysconf(_SC_GETPW_R_SIZE_MAX) */
 		int err;
 
 		if (setgid(vpninfo->gid_csd)) {
@@ -1138,17 +1139,17 @@ int set_csd_user(struct openconnect_info *vpninfo)
 			return -err;
 		}
 
-		if (!(pw = getpwuid(vpninfo->uid_csd))) {
-			err = errno;
+		if ((err = getpwuid_r(vpninfo->uid_csd, &pwd, buffer, sizeof(buffer),
+				&result)) || !result) {
 			fprintf(stderr, _("Invalid user uid=%ld: %s\n"),
 				(long)vpninfo->uid_csd, strerror(err));
 			return -err;
 		}
-		setenv("HOME", pw->pw_dir, 1);
-		if (chdir(pw->pw_dir)) {
+		setenv("HOME", result->pw_dir, 1);
+		if (chdir(result->pw_dir)) {
 			err = errno;
 			fprintf(stderr, _("Failed to change to CSD home directory '%s': %s\n"),
-				pw->pw_dir, strerror(err));
+				result->pw_dir, strerror(err));
 			return -err;
 		}
 	}
diff --git a/main.c b/main.c
index b7179a2e..b02e8e02 100644
--- a/main.c
+++ b/main.c
@@ -1586,7 +1586,7 @@ static void print_connection_info(struct openconnect_info *vpninfo)
 		     dtls_state);
 	if (vpninfo->auth_expiration != 0) {
 		char buf[80];
-		struct tm *tm = localtime(&&vpninfo->auth_expiration);
+		struct tm *tm = localtime(&vpninfo->auth_expiration);
 		strftime(buf, 80, "%a, %d %b %Y %H:%M:%S %Z", tm);
 		vpn_progress(vpninfo, PRG_INFO,
 			     _("Session authentication will expire at %s\n"),
-- 
2.50.1