[Libguestfs] [PATCH libnbd 4/4] fuzzing: Use the new nbd_connect_socket API.

[Richard W.M. Jones]

Simplifies the code and avoids having a Unix domain socket on disk.
---
 fuzzing/libnbd-fuzz-wrapper.c | 78 ++++++++++-------------------------
 1 file changed, 21 insertions(+), 57 deletions(-)

diff --git a/fuzzing/libnbd-fuzz-wrapper.c b/fuzzing/libnbd-fuzz-wrapper.c
index ba3840a..bfaa072 100644
--- a/fuzzing/libnbd-fuzz-wrapper.c
+++ b/fuzzing/libnbd-fuzz-wrapper.c
@@ -35,22 +35,18 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/wait.h>
-#include <sys/un.h>
 
 #include <libnbd.h>
 
-static void client (const char *sockpath);
+static void client (int s);
 static void server (int fd, int s);
 
 int
 main (int argc, char *argv[])
 {
   int fd;
-  char tmpdir[] = "/tmp/sockXXXXXX";
-  char *sockpath;
-  struct sockaddr_un addr;
   pid_t pid;
-  int s, r, status;
+  int sv[2], r, status;
 
   if (argc != 2) {
     fprintf (stderr, "libnbd-fuzz-wrapper testcase\n");
@@ -64,29 +60,9 @@ main (int argc, char *argv[])
     exit (EXIT_FAILURE);
   }
 
-  /* Create a randomly named Unix domain socket. */
-  if (mkdtemp (tmpdir) == NULL) {
-    perror ("mkdtemp");
-    exit (EXIT_FAILURE);
-  }
-  if (asprintf (&sockpath, "%s/sock", tmpdir) == -1) {
-    perror ("asprintf");
-    exit (EXIT_FAILURE);
-  }
-
-  s = socket (AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0);
-  if (s == -1) {
-    perror ("socket");
-    exit (EXIT_FAILURE);
-  }
-  addr.sun_family = AF_UNIX;
-  memcpy (addr.sun_path, sockpath, strlen (sockpath) + 1);
-  if (bind (s, (struct sockaddr *) &addr, sizeof addr) == -1) {
-    perror (sockpath);
-    exit (EXIT_FAILURE);
-  }
-  if (listen (s, 1) == -1) {
-    perror ("listen");
+  /* Create a connected socket. */
+  if (socketpair (AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0, sv) == -1) {
+    perror ("socketpair");
     exit (EXIT_FAILURE);
   }
 
@@ -101,9 +77,12 @@ main (int argc, char *argv[])
 
   if (pid > 0) {
     /* Parent: libnbd client. */
-    close (s);
+    close (sv[1]);
     close (fd);
-    client (sockpath);
+
+    client (sv[0]);
+
+    close (sv[0]);
 
     r = wait (&status);
     if (r == -1) {
@@ -117,19 +96,17 @@ main (int argc, char *argv[])
   }
 
   /* Child: phony NBD server. */
-  server (fd, s);
+  close (sv[0]);
+
+  server (fd, sv[1]);
 
-  /* Clean up the socket and directory. */
-  close (s);
-  close (fd);
-  unlink (sockpath);
-  rmdir (tmpdir);
+  close (sv[1]);
 
   _exit (EXIT_SUCCESS);
 }
 
 static void
-client (const char *sockpath)
+client (int sock)
 {
   struct nbd_handle *nbd;
   char buf[512];
@@ -144,7 +121,7 @@ client (const char *sockpath)
    * interested in whether the process crashes.
    */
   /* This tests the handshake phase. */
-  nbd_connect_unix (nbd, sockpath);
+  nbd_connect_socket (nbd, sock);
 
   /* XXX We should do some more complicated operations here,
    * eg exercising structured reads.
@@ -155,28 +132,15 @@ client (const char *sockpath)
 }
 
 static void
-server (int fd, int listen_sock)
+server (int fd, int sock)
 {
-  int s;
   struct pollfd pfds[1];
   char rbuf[512], wbuf[512];
   size_t wsize = 0;
   ssize_t r;
-  int flags;
-
-  /* Accept a single connection on the socket. */
-  s = accept (listen_sock, NULL, NULL);
-  if (s == -1) {
-    perror ("accept");
-    _exit (EXIT_FAILURE);
-  }
-
-  /* Set the accepted socket to non-blocking mode. */
-  flags = fcntl (s, F_GETFL, 0);
-  if (flags >= 0) fcntl (s, F_SETFL, flags|O_NONBLOCK);
 
   for (;;) {
-    pfds[0].fd = s;
+    pfds[0].fd = sock;
     pfds[0].events = POLLIN;
     if (wsize >= 0 || fd >= 0) pfds[0].events |= POLLOUT;
     pfds[0].revents = 0;
@@ -191,7 +155,7 @@ server (int fd, int listen_sock)
 
     /* We can read from the client socket.  Just throw away anything sent. */
     if ((pfds[0].revents & POLLIN) != 0) {
-      r = read (s, rbuf, sizeof rbuf);
+      r = read (sock, rbuf, sizeof rbuf);
       if (r == -1 && errno != EINTR) {
         perror ("read");
         return;
@@ -205,7 +169,7 @@ server (int fd, int listen_sock)
       /* Write more data from the wbuf. */
       if (wsize > 0) {
       morewrite:
-        r = write (s, wbuf, wsize);
+        r = write (sock, wbuf, wsize);
         if (r == -1 && errno != EAGAIN && errno != EWOULDBLOCK) {
           perror ("write");
           return;
@@ -224,7 +188,7 @@ server (int fd, int listen_sock)
         }
         else if (r == 0) {
           fd = -1;              /* ignore the file from now on */
-          shutdown (s, SHUT_WR);
+          shutdown (sock, SHUT_WR);
         }
         else {
           wsize = r;
-- 
2.23.0