From f7cd45464fd7c037f6a60098ae77760998b3b4b6 Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Fri, 10 May 2019 15:25:43 +0200
Subject: Initial commit

---
 src/rpc.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)
 create mode 100644 src/rpc.c

(limited to 'src/rpc.c')

diff --git a/src/rpc.c b/src/rpc.c
new file mode 100644
index 0000000..e49547e
--- /dev/null
+++ b/src/rpc.c
@@ -0,0 +1,132 @@
+#include "rpc.h"
+#include "util.h"
+#include "main.h"
+#include "userlist.h"
+
+#include <poll.h>
+#include <sys/types.h>  
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/un.h>
+#include <stdio.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+
+#define SOCKPATH "/run/idle-daemon"
+
+static void handleClient( int fd, struct ucred *user );
+
+int rpcOpen()
+{
+	int fd = socket( AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0 );
+	if ( fd == -1 ) {
+		perror( "Cannot create local RPC socket" );
+		return -1;
+	}
+	struct sockaddr_un address = {
+		.sun_family = AF_UNIX,
+		.sun_path = SOCKPATH,
+	};
+	unlink( SOCKPATH );
+	if ( bind( fd, (struct sockaddr *)&address, sizeof(address) ) == -1 ) {
+		perror( "Could not bind RPC socket" );
+		close( fd );
+		return -1;
+	}
+	chmod( SOCKPATH, 0777 );
+	if ( listen( fd, 10 ) == -1 ) {
+		perror( "Could not listen() on RPC socket" );
+		close( fd );
+		return -1;
+	}
+	return fd;
+}
+
+void rpcWait( int listenFd, int seconds )
+{
+	waitRead( listenFd, seconds * 1000 );
+}
+
+void rpcHandle( int listenFd )
+{
+	int fd;
+	while ( ( fd = accept( listenFd, NULL, NULL ) ) != -1 ) {
+		// Determine who connected
+		socklen_t len;
+		struct ucred ucred;
+		len = sizeof(struct ucred);
+		if ( getsockopt( fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len ) == -1 ) {
+			perror( "Could not get credentials of connection" );
+			close( fd ); // TODO: Allow more for root (eg. cancel reboot/poweroff)
+			continue;
+		}
+		if ( ! doublefork() )
+			continue; // Parent continues
+		handleClient( fd, &ucred );
+		exit( 0 );
+	}
+	if ( errno != EAGAIN && errno != EWOULDBLOCK ) {
+		perror( "accept() on RPC socket failed" );
+	}
+}
+
+static void handleClient( int fd, struct ucred *user )
+{
+	//printf( "Credentials from SO_PEERCRED: pid=%ld, euid=%ld, egid=%ld\n",
+	//	(long) ucred.pid, (long) ucred.uid, (long) ucred.gid );
+	// Make socket blocking (should be default on linux after accept() but...)
+	(void)user;
+	int flags = fcntl( fd, F_GETFL, 0 );
+	if ( flags != -1 ) {
+		fcntl( fd, F_SETFL, flags & ~O_NONBLOCK );
+	}
+	// But set timeouts
+	struct timeval tv = {
+		.tv_sec = 2,
+	};
+	setsockopt( fd, SOL_SOCKET, SO_RCVTIMEO, (const char*)&tv, sizeof(tv) );
+	setsockopt( fd, SOL_SOCKET, SO_SNDTIMEO, (const char*)&tv, sizeof(tv) );
+	// Now read request
+	char buffer[1000];
+	ssize_t len = read( fd, buffer, sizeof(buffer) - 1 );
+	if ( len <= 0 )
+		return;
+	buffer[len] = '\0';
+	if ( strncmp( buffer, "get", 3 ) != 0 ) {
+		write( fd, "error", 5 );
+	} else {
+		// Get request
+		FILE *s = fdopen( fd, "w" );
+		if ( s == NULL ) {
+			perror( "Cannot wrap socket in stream" );
+			return;
+		}
+		// 1) Global state
+		time_t deadline;
+		const char *name = "none";
+		main_getStatus( &name, &deadline );
+		fprintf( s, "[General]\n"
+				"nextAction=%s\n"
+				"nextActionTime=%lld\n",
+				name, (long long)deadline );
+		// 2) Requested sessions
+		char *tok = strtok( buffer + 4, " \t\n\r" );
+		while ( tok != NULL ) {
+			struct user *user = main_getUser( tok );
+			if ( user != NULL ) {
+				fprintf( s, "[%s]\n"
+						"logoutTime=%lld\n"
+						"locked=%d\n",
+						tok, (long long)user->logoutTime, (int)user->isLocked );
+			}
+			tok = strtok( NULL, " \t\n\r" );
+		}
+		fflush( s );
+	}
+	shutdown( fd, SHUT_WR );
+	read( fd, buffer, sizeof(buffer) );
+	close( fd );
+}
+
-- 
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