feature: add doas support in firecfg and jailcheck

Closes netblue30#5899.

Suggested-by: @shaggonit

Author: kmk3

src/firecfg/main.c

@@ -289,7 +289,10 @@ static void set_links_homedir(const char *homedir) {
 }
 
 static const char *get_sudo_user(void) {
-	const char *user = getenv("SUDO_USER");
+	const char *doas_user = getenv("DOAS_USER");
+	const char *sudo_user = getenv("SUDO_USER");
+	const char *user = doas_user ? doas_user : sudo_user;
+
 	if (!user) {
 		user = getpwuid(getuid())->pw_name;
 		if (!user) {

src/jailcheck/main.c

@@ -86,7 +86,7 @@ int main(int argc, char **argv) {
 
 	// user setup
 	if (getuid() != 0) {
-		fprintf(stderr, "Error: you need to be root (via sudo) to run this program\n");
+		fprintf(stderr, "Error: you need to be root (via sudo or doas) to run this program\n");
 		exit(1);
 	}
 	user_name = get_sudo_user();

src/jailcheck/utils.c

@@ -26,7 +26,10 @@
 #define BUFLEN 4096
 
 char *get_sudo_user(void) {
-	char *user = getenv("SUDO_USER");
+	char *doas_user = getenv("DOAS_USER");
+	char *sudo_user = getenv("SUDO_USER");
+	char *user = doas_user ? doas_user : sudo_user;
+
 	if (!user) {
 		user = getpwuid(getuid())->pw_name;
 		if (!user) {

src/man/firecfg.1.in

@@ -23,7 +23,9 @@ The integration covers:
 - programs started by clicking on file icons in file manager - only Cinnamon, KDE, LXDE/LXQT, MATE and XFCE
 desktop managers are supported in this moment
 .RE
-
+.PP
+Note: The examples use \fBsudo\fR, but \fBdoas\fR is also supported.
+.PP
 To set it up, run "sudo firecfg" after installing Firejail software.
 The same command should also be run after
 installing new programs. If the program is supported by Firejail, the symbolic link in /usr/local/bin

src/man/jailcheck.1.in

@@ -24,9 +24,8 @@ them from inside the sandbox.
 \fB5. Seccomp test
 .TP
 \fB6. Networking test
-.TP
-The program is started as root using sudo.
-
+.PP
+The program should be started using \fBsudo\fR or \fBdoas\fR.
 .SH OPTIONS
 .TP
 \fB\-\-debug