From: Michael Tremer <michael.tremer@ipfire.org>
Date: Fri, 8 Dec 2023 15:47:20 +0000 (+0000)
Subject: jail: Have the child process allocate a new PTY
X-Git-Tag: 0.9.30~1288
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=92f2120ef7c40c6d67cb2940427e90f20aaad307;p=pakfire.git

jail: Have the child process allocate a new PTY

The master file descriptor is being sent to the parent process.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/libpakfire/jail.c b/src/libpakfire/jail.c
index ed1223d65..264664ea8 100644
--- a/src/libpakfire/jail.c
+++ b/src/libpakfire/jail.c
@@ -838,6 +838,16 @@ static int pakfire_jail_epoll_add_fd(struct pakfire_jail* jail, int epollfd, int
 	return 0;
 }
 
+static int pakfire_jail_setup_pty_forwarding(struct pakfire_jail* jail,
+		struct pakfire_jail_exec* ctx, const int epollfd, const int fd) {
+	// Store the file descriptor
+	ctx->consolefd = fd;
+
+	// XXX TODO
+
+	return 0;
+}
+
 static int pakfire_jail_wait(struct pakfire_jail* jail, struct pakfire_jail_exec* ctx) {
 	int epollfd = -1;
 	struct epoll_event events[EPOLL_MAX_EVENTS];
@@ -1036,7 +1046,14 @@ static int pakfire_jail_wait(struct pakfire_jail* jail, struct pakfire_jail_exec
 					if (r)
 						goto ERROR;
 
-					// XXX Do something with the file descriptor
+					// Setup PTY forwarding
+					if (ctx->consolefd < 0) {
+						r = pakfire_jail_setup_pty_forwarding(jail, ctx, epollfd, fd);
+						if (r) {
+							CTX_ERROR(jail->ctx, "Failed setting up PTY forwarding: %s\n", strerror(-r));
+							goto ERROR;
+						}
+					}
 
 					// Don't fall through to log processing
 					continue;
@@ -1693,7 +1710,6 @@ static int pakfire_jail_switch_root(struct pakfire_jail* jail, const char* root)
 	return 0;
 }
 
-#if 0
 static int pakfire_jail_open_pty(struct pakfire_jail* jail, struct pakfire_jail_exec* ctx) {
 	int r;
 
@@ -1709,14 +1725,15 @@ static int pakfire_jail_open_pty(struct pakfire_jail* jail, struct pakfire_jail_
 
 	CTX_DEBUG(jail->ctx, "Allocated console at %s (%d)\n", ctx->console, ctx->consolefd);
 
+#if 0
 	// Create a symlink
 	r = pakfire_symlink(jail->ctx, "/dev/console", ctx->console);
 	if (r)
 		return r;
+#endif
 
 	return r;
 }
-#endif
 
 static int pakfire_jail_child(struct pakfire_jail* jail, struct pakfire_jail_exec* ctx,
 		const char* argv[]) {
@@ -1782,27 +1799,13 @@ static int pakfire_jail_child(struct pakfire_jail* jail, struct pakfire_jail_exe
 		return 126;
 	}
 
+	const int socket_send = pakfire_jail_get_pipe_to_write(jail, &ctx->socket);
+
 	// Mount all default stuff
 	r = pakfire_mount_all(jail->pakfire, PAKFIRE_MNTNS_INNER, 0);
 	if (r)
 		return 126;
 
-#if 0
-	// Create a new session
-	r = setsid();
-	if (r < 0) {
-		CTX_ERROR(jail->ctx, "Could not create a new session: %s\n", strerror(errno));
-		return 126;
-	}
-
-	// Allocate a new PTY
-	r = pakfire_jail_open_pty(jail, ctx);
-	if (r) {
-		CTX_ERROR(jail->ctx, "Could not allocate a new PTY: %s\n", strerror(-r));
-		return 126;
-	}
-#endif
-
 	const char* root = pakfire_get_path(jail->pakfire);
 	const char* arch = pakfire_get_effective_arch(jail->pakfire);
 
@@ -1862,6 +1865,36 @@ static int pakfire_jail_child(struct pakfire_jail* jail, struct pakfire_jail_exe
 		}
 	}
 
+#if 0
+	// Create a new session
+	r = setsid();
+	if (r < 0) {
+		CTX_ERROR(jail->ctx, "Could not create a new session: %s\n", strerror(errno));
+		return r;
+	}
+#endif
+
+	// Allocate a new PTY
+	r = pakfire_jail_open_pty(jail, ctx);
+	if (r) {
+		CTX_ERROR(jail->ctx, "Could not allocate a new PTY: %s\n", strerror(-r));
+		return r;
+	}
+
+	// Send the PTY master to the parent process
+	r = pakfire_jail_send_fd(jail, socket_send, ctx->consolefd);
+	if (r) {
+		CTX_ERROR(jail->ctx, "Failed sending the PTY master to the parent: %s\n", strerror(-r));
+		return r;
+	}
+
+	// Close the master of the PTY
+	close(ctx->consolefd);
+	ctx->consolefd = -1;
+
+	// Close the socket
+	close(socket_send);
+
 	// Close other end of log pipes
 	close(ctx->pipes.log_INFO[0]);
 	close(ctx->pipes.log_ERROR[0]);
@@ -1995,6 +2028,8 @@ static int __pakfire_jail_exec(struct pakfire_jail* jail, const char* argv[],
 		},
 
 		.pidfd = -1,
+
+		.consolefd = -1,
 	};
 
 	DEBUG(jail->pakfire, "Executing jail...\n");
@@ -2162,6 +2197,8 @@ ERROR:
 	pakfire_jail_close_pipe(jail, ctx.pipes.stderr);
 	if (ctx.pidfd >= 0)
 		close(ctx.pidfd);
+	if (ctx.consolefd >= 0)
+		close(ctx.consolefd);
 	pakfire_jail_close_pipe(jail, ctx.pipes.log_INFO);
 	pakfire_jail_close_pipe(jail, ctx.pipes.log_ERROR);
 #ifdef ENABLE_DEBUG