A complete telnetd.

lwIP crashes after a client connects and sh prints the prompt.

A complete telnetd.
0c380176 · Silas Boyd-Wickizer · abc4e71f · 0c380176 · 0c380176
--- a/Makefile
+++ b/Makefile
@@ -151,7 +151,7 @@ mscan.kern: $(O)/kernel
 ##
 QEMUOPTS = -smp $(QEMUSMP) -m 512 -serial mon:stdio -nographic \
 	-net user -net nic,model=e1000 \
-	-net dump,file=qemu.pcap
+	-net dump,file=qemu.pcap -redir tcp:2323::23

 qemu: $(O)/kernel
 	$(QEMU) $(QEMUOPTS) -kernel $(O)/kernel

--- a/telnetd.c
+++ b/telnetd.c
@@ -24,16 +24,38 @@ main(void)
  if (r < 0)
    die("telnetd listen: %d\n", r);

+  printf(1, "telnetd: port 23\n");
+
  for (;;) {
-    socklen_t socklen = sizeof(sin);
-    int ss = accept(s, (struct sockaddr *)&sin, &socklen);
+    socklen_t socklen;
+    int ss;
+    int pid;
+
+    socklen = sizeof(sin);
+    ss = accept(s, (struct sockaddr *)&sin, &socklen);
    if (ss < 0) {
-      printf(1, "telnetd accept: %d\n", ss);
+      printf(2, "telnetd accept: %d\n", ss);
      continue;
    }
+    printf(1, "telnetd: connection\n");

-    printf(1, "Got one!\n");
-    // XXX fork, exec sh, etc..
+    pid = fork(0);
+    if (pid < 0) {
+      printf(2, "telnetd fork: %d\n", pid);
+      close(ss);
+      continue;
+    }
+    if (pid == 0) {
+      static char *argv[] = { "sh", 0 };
+      close(0);
+      close(1);
+      close(2);
+      dup(ss);
+      dup(ss);
+      dup(ss);
+      exec("sh", argv);
+      exit();
+    }
    close(ss);
  }
 }