zcip: make it work on NOMMU (+ improve NOMMU support machinery)

fsck: fix bad English in a comment

6 files changed, 100 insertions, 88 deletions

diff --git a/TODO_config_nommu b/TODO_config_nommu
index 74095aa9a..695ac1114 100644
--- a/TODO_config_nommu
+++ b/TODO_config_nommu
@@ -5,7 +5,7 @@
 #
 # Automatically generated make config: don't edit
 # Busybox version: 1.6.0.svn
-# Mon Mar 26 15:00:56 2007
+# Mon Mar 26 18:36:12 2007
 #
 CONFIG_HAVE_DOT_CONFIG=y
 
@@ -266,7 +266,7 @@ CONFIG_RESET=y
 CONFIG_RESIZE=y
 CONFIG_FEATURE_RESIZE_PRINT=y
 CONFIG_SETCONSOLE=y
-# CONFIG_FEATURE_SETCONSOLE_LONG_OPTIONS is not set
+CONFIG_FEATURE_SETCONSOLE_LONG_OPTIONS=y
 CONFIG_SETKEYCODES=y
 CONFIG_SETLOGCONS=y
 
@@ -605,7 +605,7 @@ CONFIG_WGET=y
 CONFIG_FEATURE_WGET_STATUSBAR=y
 CONFIG_FEATURE_WGET_AUTHENTICATION=y
 CONFIG_FEATURE_WGET_LONG_OPTIONS=y
-# CONFIG_ZCIP is not set
+CONFIG_ZCIP=y
 
 #
 # Process Utilities
diff --git a/e2fsprogs/fsck.c b/e2fsprogs/fsck.c
index 447b4d008..b70fd7088 100644
--- a/e2fsprogs/fsck.c
+++ b/e2fsprogs/fsck.c
@@ -509,12 +509,7 @@ static struct fsck_instance *wait_one(int flags)
                 goto ret_inst;
         }
 
-        /*
-         * gcc -Wall fails saving throw against stupidity
-         * (inst and prev are thought to be uninitialized variables)
-         */
-        inst = prev = NULL;
-
+        inst = prev = NULL; /* for gcc */
         do {
                 pid = waitpid(-1, &status, flags);
                 kill_all_if_cancel_requested();
diff --git a/include/libbb.h b/include/libbb.h
index 32e099b54..67fd2af21 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -263,6 +263,13 @@ char *xrealloc_getcwd_or_warn(char *cwd);
 char *xmalloc_readlink_or_warn(const char *path);
 char *xmalloc_realpath(const char *path);
 extern void xstat(const char *filename, struct stat *buf);
+/* Unlike waitpid, waits ONLY for one process,
+ * It's safe to pass negative 'pids' from failed [v]fork -
+ * wait4pid will return -1 and ECHILD in errno.
+ * IOW: rc = wait4pid(spawn(argv));
+ *      if (rc < 0) bb_perror_msg("%s", argv[0]);
+ *      if (rc > 0) bb_error_msg("exit code: %d", rc);
+ */
 extern int wait4pid(int pid);
 extern void xsetgid(gid_t gid);
 extern void xsetuid(uid_t uid);
diff --git a/libbb/vfork_daemon_rexec.c b/libbb/vfork_daemon_rexec.c
index 89ae9a73c..ec8b9b1d7 100644
--- a/libbb/vfork_daemon_rexec.c
+++ b/libbb/vfork_daemon_rexec.c
@@ -40,11 +40,14 @@ pid_t spawn(char **argv)
                  * (but don't run atexit() stuff, which would screw up parent.)
                  */
                 failed = errno;
-                _exit(0);
+                _exit(111);
         }
         /* parent */
-        /* Unfortunately, this is not reliable: vfork()
-         * can be equivalent to fork() according to standards */
+        /* Unfortunately, this is not reliable: according to standards
+         * vfork() can be equivalent to fork() and we won't see value
+         * of 'failed'.
+         * Interested party can wait on pid and learn exit code.
+         * If 111 - then it (most probably) failed to exec */
         if (failed) {
                 errno = failed;
                 return -1;
diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index 14bd62a15..7f870ac8b 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -192,9 +192,16 @@ int wait4pid(int pid)
 {
         int status;
 
-        if (pid == -1 || waitpid(pid, &status, 0) == -1) return -1;
-        if (WIFEXITED(status)) return WEXITSTATUS(status);
-        if (WIFSIGNALED(status)) return WTERMSIG(status);
+        if (pid <= 0) {
+                errno = ECHILD;
+                return -1;
+        }
+        if (waitpid(pid, &status, 0) == -1)
+                return -1;
+        if (WIFEXITED(status))
+                return WEXITSTATUS(status);
+        if (WIFSIGNALED(status))
+                return WTERMSIG(status) + 10000;
         return 0;
 }
 
diff --git a/networking/zcip.c b/networking/zcip.c
index c0cf665dd..6035b91e1 100644
--- a/networking/zcip.c
+++ b/networking/zcip.c
@@ -70,10 +70,6 @@ enum {
 #define VDBG(fmt,args...) \
         do { } while (0)
 
-static unsigned opts;
-#define FOREGROUND (opts & 1)
-#define QUIT (opts & 2)
-
 /**
  * Pick a random link local IP address on 169.254/16, except that
  * the first and last 256 addresses are reserved.
@@ -128,49 +124,30 @@ static void arp(int fd, struct sockaddr *saddr, int op,
 }
 
 /**
- * Run a script.
+ * Run a script. argv[2] is already NULL.
  */
-static int run(const char *script, const char *arg, const char *intf, struct in_addr *ip)
+static int run(char *argv[3], const char *intf, struct in_addr *ip)
 {
-        int pid, status;
-        const char *why;
+        int status;
 
-        if(1) { //always true: if (script != NULL)
-                VDBG("%s run %s %s\n", intf, script, arg);
-                if (ip != NULL) {
-                        char *addr = inet_ntoa(*ip);
-                        setenv("ip", addr, 1);
-                        bb_info_msg("%s %s %s", arg, intf, addr);
-                }
+        VDBG("%s run %s %s\n", intf, argv[0], argv[1]);
 
-                pid = vfork();
-                if (pid < 0) {                  // error
-                        why = "vfork";
-                        goto bad;
-                } else if (pid == 0) {          // child
-                        execl(script, script, arg, NULL);
-                        bb_perror_msg("execl");
-                        _exit(EXIT_FAILURE);
-                }
+        if (ip) {
+                char *addr = inet_ntoa(*ip);
+                setenv("ip", addr, 1);
+                bb_info_msg("%s %s %s", argv[1], intf, addr);
+        }
 
-                if (waitpid(pid, &status, 0) <= 0) {
-                        why = "waitpid";
-                        goto bad;
-                }
-                if (WEXITSTATUS(status) != 0) {
-                        bb_error_msg("script %s failed, exit=%d",
-                                script, WEXITSTATUS(status));
-                        return -errno;
-                }
+        status = wait4pid(spawn(argv));
+        if (status < 0) {
+                bb_perror_msg("%s %s", argv[1], intf);
+                return -errno;
         }
-        return 0;
-bad:
-        status = -errno;
-        bb_perror_msg("%s %s, %s", arg, intf, why);
+        if (status != 0)
+                bb_error_msg("script %s %s failed, exitcode=%d", argv[0], argv[1], status);
         return status;
 }
 
-
 /**
  * Return milliseconds of random delay, up to "secs" seconds.
  */
@@ -182,43 +159,58 @@ static unsigned ATTRIBUTE_ALWAYS_INLINE ms_rdelay(unsigned secs)
 /**
  * main program
  */
-
-/* Used to be auto variables on main() stack, but
- * most of them were zero-inited. Moving them to bss
- * is more space-efficient.
- */
-static  const struct in_addr null_ip; // = { 0 };
-static  const struct ether_addr null_addr; // = { {0, 0, 0, 0, 0, 0} };
-
-static  struct sockaddr saddr; // memset(0);
-static  struct in_addr ip; // = { 0 };
-static  struct ifreq ifr; //memset(0);
-
-static  char *intf; // = NULL;
-static  char *script; // = NULL;
-static  suseconds_t timeout; // = 0;    // milliseconds
-static  unsigned conflicts; // = 0;
-static  unsigned nprobes; // = 0;
-static  unsigned nclaims; // = 0;
-static  int ready; // = 0;
-static  int verbose; // = 0;
-static  int state = PROBE;
-
 int zcip_main(int argc, char *argv[]);
 int zcip_main(int argc, char *argv[])
 {
+        int state = PROBE;
         struct ether_addr eth_addr;
         const char *why;
         int fd;
+        char *r_opt;
+        unsigned opts;
+
+        /* Ugly trick, but I want these zeroed in one go */
+        struct {
+                const struct in_addr null_ip;
+                const struct ether_addr null_addr;
+                struct sockaddr saddr;
+                struct in_addr ip;
+                struct ifreq ifr;
+                char *intf;
+                char *script_av[3];
+                suseconds_t timeout; // milliseconds
+                unsigned conflicts;
+                unsigned nprobes;
+                unsigned nclaims;
+                int ready;
+                int verbose;
+        } L;
+#define null_ip   (L.null_ip  )
+#define null_addr (L.null_addr)
+#define saddr     (L.saddr    )
+#define ip        (L.ip       )
+#define ifr       (L.ifr      )
+#define intf      (L.intf     )
+#define script_av (L.script_av)
+#define timeout   (L.timeout  )
+#define conflicts (L.conflicts)
+#define nprobes   (L.nprobes  )
+#define nclaims   (L.nclaims  )
+#define ready     (L.ready    )
+#define verbose   (L.verbose  )
+
+        memset(&L, 0, sizeof(L));
 
+#define FOREGROUND (opts & 1)
+#define QUIT       (opts & 2)
         // parse commandline: prog [options] ifname script
-        char *r_opt;
-        opt_complementary = "vv:vf"; // -v accumulates and implies -f
+        // exactly 2 args; -v accumulates and implies -f
+        opt_complementary = "=2:vv:vf";
         opts = getopt32(argc, argv, "fqr:v", &r_opt, &verbose);
         if (!FOREGROUND) {
                 /* Do it early, before all bb_xx_msg calls */
-                logmode = LOGMODE_SYSLOG;
                 openlog(applet_name, 0, LOG_DAEMON);
+                logmode |= LOGMODE_SYSLOG;
         }
         if (opts & 4) { // -r n.n.n.n
                 if (inet_aton(r_opt, &ip) == 0
@@ -227,16 +219,21 @@ int zcip_main(int argc, char *argv[])
                         bb_error_msg_and_die("invalid link address");
                 }
         }
+        // On NOMMU reexec early (or else we will rerun things twice)
+#ifdef BB_NOMMU
+        if (!FOREGROUND)
+                bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
+#endif
         argc -= optind;
         argv += optind;
-        if (argc != 2)
-                bb_show_usage();
+
         intf = argv[0];
-        script = argv[1];
+        script_av[0] = argv[1];
         setenv("interface", intf, 1);
 
         // initialize the interface (modprobe, ifup, etc)
-        if (run(script, "init", intf, NULL) < 0)
+        script_av[1] = (char*)"init";
+        if (run(script_av, intf, NULL))
                 return EXIT_FAILURE;
 
         // initialize saddr
@@ -271,8 +268,9 @@ int zcip_main(int argc, char *argv[])
 
         // daemonize now; don't delay system startup
         if (!FOREGROUND) {
-//NOMMU
+#ifndef BB_NOMMU
                 bb_daemonize(DAEMON_CHDIR_ROOT);
+#endif
                 bb_info_msg("start, interface %s", intf);
         }
 
@@ -375,7 +373,8 @@ int zcip_main(int argc, char *argv[])
                                         state = MONITOR;
                                         // link is ok to use earlier
                                         // FIXME update filters
-                                        run(script, "config", intf, &ip);
+                                        script_av[1] = (char*)"config";
+                                        run(script_av, intf, &ip);
                                         ready = 1;
                                         conflicts = 0;
                                         timeout = -1; // Never timeout in the monitor state.
@@ -429,8 +428,8 @@ int zcip_main(int argc, char *argv[])
                                         // this shouldn't necessarily exit.
                                         bb_error_msg("%s: poll error", intf);
                                         if (ready) {
-                                                run(script, "deconfig",
-                                                                intf, &ip);
+                                                script_av[1] = (char*)"deconfig";
+                                                run(script_av, intf, &ip);
                                         }
                                         return EXIT_FAILURE;
                                 }
@@ -516,7 +515,8 @@ int zcip_main(int argc, char *argv[])
                                         state = PROBE;
                                         VDBG("defend conflict -- starting over\n");
                                         ready = 0;
-                                        run(script, "deconfig", intf, &ip);
+                                        script_av[1] = (char*)"deconfig";
+                                        run(script_av, intf, &ip);
 
                                         // restart the whole protocol
                                         pick(&ip);
@@ -542,7 +542,7 @@ int zcip_main(int argc, char *argv[])
                         goto bad;
                 } // switch poll
         }
-bad:
+ bad:
         bb_perror_msg("%s, %s", intf, why);
         return EXIT_FAILURE;
 }