Make defconfig build for nommu.

Adds XVFORK() macro, teaches xpopen_both() to call /proc/self/exe with NULL
argv (and converts cpio -p to use that), adds TOYBOX_FORK guards to some
unconverted commands.

10 files changed, 43 insertions, 41 deletions

diff --git a/toys/other/login.c b/toys/other/login.c
index c727bf96..7f9559aa 100644
--- a/toys/other/login.c
+++ b/toys/other/login.c
@@ -159,9 +159,7 @@ void login_main(void)
   syslog(LOG_INFO, "%s logged in on %s %s %s", pwd->pw_name,
     ttyname(tty), hh ? "from" : "", hh ? TT.hostname : "");
 
-  // can't xexec here because name doesn't match argv[0]
-  snprintf(toybuf, sizeof(toybuf)-1, "-%s", basename_r(pwd->pw_shell));
-  toy_exec((char *[]){toybuf, 0});
-  execl(pwd->pw_shell, toybuf, NULL);
-  error_exit("Failed to spawn shell");
+  // not using xexec(), login calls absolute path from filesystem so must exec()
+  execl(pwd->pw_shell, xmprintf("-%s", pwd->pw_shell), (char *)0);
+  perror_exit("exec shell '%s'", pwd->pw_shell);
 }
diff --git a/toys/other/nbd_client.c b/toys/other/nbd_client.c
index a82ff7c8..3ad366f3 100644
--- a/toys/other/nbd_client.c
+++ b/toys/other/nbd_client.c
@@ -12,6 +12,7 @@ USE_NBD_CLIENT(OLDTOY(nbd-client, nbd_client, TOYFLAG_USR|TOYFLAG_BIN))
 
 config NBD_CLIENT
   bool "nbd-client"
+  depends on TOYBOX_FORK
   default y
   help
     usage: nbd-client [-ns] HOST PORT DEVICE
diff --git a/toys/other/netcat.c b/toys/other/netcat.c
index 3cc3f0a0..1c75eb26 100644
--- a/toys/other/netcat.c
+++ b/toys/other/netcat.c
@@ -26,10 +26,10 @@ config NETCAT_LISTEN
   bool "netcat server options (-let)"
   default y
   depends on NETCAT
+  depends on TOYBOX_FORK
   help
-    usage: netcat [-t] [-lL COMMAND...]
+    usage: netcat [-lL COMMAND...]
 
-    -t	allocate tty (must come before -l or -L)
     -l	listen for one incoming connection.
     -L	listen for multiple incoming connections (server mode).
 
@@ -38,6 +38,16 @@ config NETCAT_LISTEN
 
     For a quick-and-dirty server, try something like:
     netcat -s 127.0.0.1 -p 1234 -tL /bin/bash -l
+
+config NETCAT_LISTEN_TTY
+  bool
+  default y
+  depends on NETCAT_LISTEN
+  depends on TOYBOX_FORK
+  help
+    usage: netcat [-t]
+
+    -t	allocate tty (must come before -l or -L)
 */
 
 #define FOR_netcat
@@ -139,7 +149,7 @@ void netcat_main(void)
       // Do we need to return immediately because -l has arguments?
 
       if ((toys.optflags & FLAG_l) && toys.optc) {
-        if (xfork()) goto cleanup;
+        if (CFG_TOYBOX_FORK && xfork()) goto cleanup;
         close(0);
         close(1);
         close(2);
@@ -161,7 +171,10 @@ void netcat_main(void)
         // Do we need to fork and/or redirect for exec?
 
         else {
-          if (toys.optflags&FLAG_L) child = fork();
+          if (toys.optflags&FLAG_L) {
+            toys.stacktop = 0;
+            child = vfork();
+          }
           if (!child && toys.optc) {
             int fd = pollfds[0].fd;
 
@@ -183,7 +196,7 @@ void netcat_main(void)
   // (Does not play well with -L, but what _should_ that do?)
   set_alarm(0);
 
-  if (CFG_NETCAT_LISTEN && (toys.optflags&(FLAG_L|FLAG_l) && toys.optc))
+  if (CFG_NETCAT_LISTEN && ((toys.optflags&(FLAG_L|FLAG_l)) && toys.optc))
     xexec(toys.optargs);
 
   // Poll loop copying stdin->socket and socket->stdout.
diff --git a/toys/other/nsenter.c b/toys/other/nsenter.c
index 18a2cd21..bda77ac1 100644
--- a/toys/other/nsenter.c
+++ b/toys/other/nsenter.c
@@ -1,14 +1,14 @@
 /* nsenter.c - Enter existing namespaces
  *
- * Copyright 2014 andy Lutomirski <luto@amacapital.net>
+ * Copyright 2014 Andy Lutomirski <luto@amacapital.net>
  *
- * No standard
+ * See http://man7.org/linux/man-pages/man1/nsenter.1.html
  *
  * unshare.c - run command in new context
  *
  * Copyright 2011 Rob Landley <rob@landley.net>
  *
- * No Standard
+ * See http://man7.org/linux/man-pages/man1/unshare.1.html
  *
 
 // Note: flags go in same order (right to left) for shared subset
@@ -149,12 +149,9 @@ void unshare_main(void)
     }
 
     if ((toys.optflags & FLAG_p) && !(toys.optflags & FLAG_F)) {
-      pid_t pid = xfork();
+      toys.exitval = xrun(toys.optargs);
 
-      if (pid) {
-        while (waitpid(pid, 0, 0) == -1 && errno == EINTR);
-        return;
-      }
+      return;
     }
   }
 
diff --git a/toys/other/setsid.c b/toys/other/setsid.c
index 83db044d..95698260 100644
--- a/toys/other/setsid.c
+++ b/toys/other/setsid.c
@@ -19,7 +19,7 @@ config SETSID
 
 void setsid_main(void)
 {
-  while (setsid()<0) if (xvfork()) _exit(0);
+  while (setsid()<0) if (XVFORK()) _exit(0);
   if (toys.optflags) {
     setpgid(0, 0);
     tcsetpgrp(0, getpid());
diff --git a/toys/other/timeout.c b/toys/other/timeout.c
index bd716e63..0e912f7c 100644
--- a/toys/other/timeout.c
+++ b/toys/other/timeout.c
@@ -62,14 +62,10 @@ void timeout_main(void)
   if (TT.s_signal && -1 == (TT.nextsig = sig_to_num(TT.s_signal)))
     error_exit("bad -s: '%s'", TT.s_signal);
 
-  if (!(TT.pid = xvfork())) xexec(toys.optargs+1);
+  if (!(TT.pid = XVFORK())) xexec(toys.optargs+1);
   else {
-    int status;
-
     xsignal(SIGALRM, handler);
     setitimer(ITIMER_REAL, &TT.itv, (void *)toybuf);
-    while (-1 == waitpid(TT.pid, &status, 0) && errno == EINTR);
-    toys.exitval = WIFEXITED(status)
-      ? WEXITSTATUS(status) : WTERMSIG(status) + 127;
+    toys.exitval = xwaitpid(TT.pid);
   }
 }
diff --git a/toys/pending/arping.c b/toys/pending/arping.c
index 3e522bdf..be43cab1 100644
--- a/toys/pending/arping.c
+++ b/toys/pending/arping.c
@@ -39,15 +39,9 @@ GLOBALS(
     char *src_ip;
 
     int sockfd;
-    unsigned start;
-    unsigned end;
-    unsigned sent_at;
-    unsigned sent_nr;
-    unsigned rcvd_nr;
-    unsigned brd_sent;
-    unsigned rcvd_req;
-    unsigned brd_rcv;
-    unsigned unicast_flag;
+    unsigned long start, end;
+    unsigned sent_at, sent_nr, rcvd_nr, brd_sent, rcvd_req, brd_rcv,
+             unicast_flag;
 )
 
 struct sockaddr_ll src_pk, dst_pk; 
diff --git a/toys/posix/cpio.c b/toys/posix/cpio.c
index 312bb939..a442f0d1 100644
--- a/toys/posix/cpio.c
+++ b/toys/posix/cpio.c
@@ -82,12 +82,15 @@ void cpio_main(void)
   // In passthrough mode, parent stays in original dir and generates archive
   // to pipe, child does chdir to new dir and reads archive from stdin (pipe).
   if (TT.pass) {
-    if (!(pid = xpopen(0, &pipe, 0))) {
+    if (toys.stacktop) {
+      // xpopen() doesn't return from child due to vfork(), instead restarts
+      // with !toys.stacktop
+      pid = xpopen(0, &pipe, 0);
+      afd = pipe;
+    } else {
+      // child
       toys.optflags |= FLAG_i;
       xchdir(TT.pass);
-    } else {
-      toys.optflags |= FLAG_o;
-      afd = pipe;
     }
   }
 
diff --git a/toys/posix/time.c b/toys/posix/time.c
index b3cfd26b..2151826d 100644
--- a/toys/posix/time.c
+++ b/toys/posix/time.c
@@ -28,7 +28,7 @@ void time_main(void)
   struct timeval tv, tv2;
 
   gettimeofday(&tv, NULL);
-  if (!(pid = xvfork())) xexec(toys.optargs);
+  if (!(pid = XVFORK())) xexec(toys.optargs);
   else {
     int stat;
     struct rusage ru;
diff --git a/toys/posix/xargs.c b/toys/posix/xargs.c
index 50c42620..b4cb80a0 100644
--- a/toys/posix/xargs.c
+++ b/toys/posix/xargs.c
@@ -111,6 +111,7 @@ void xargs_main(void)
   struct double_list *dlist = NULL, *dtemp;
   int entries, bytes, done = 0, status;
   char *data = NULL, **out;
+  pid_t pid;
 
   if (!(toys.optflags & FLAG_0)) TT.delim = '\n';
 
@@ -168,8 +169,7 @@ void xargs_main(void)
     for (dtemp = dlist; dtemp; dtemp = dtemp->next)
       handle_entries(dtemp->data, out+entries);
 
-    pid_t pid=xvfork();
-    if (!pid) {
+    if (!(pid = XVFORK())) {
       xclose(0);
       open("/dev/null", O_RDONLY);
       xexec(out);