flag parameters: socket and socketpair

This patch adds support for flag values which are ORed to the type passwd
to socket and socketpair.  The additional code is minimal.  The flag
values in this implementation can and must match the O_* flags.  This
avoids overhead in the conversion.

The internal functions sock_alloc_fd and sock_map_fd get a new parameters
and all callers are changed.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <netinet/in.h>
#include <sys/socket.h>

#define PORT 57392

/* For Linux these must be the same.  */
#define SOCK_CLOEXEC O_CLOEXEC

int
main (void)
{
  int fd;
  fd = socket (PF_INET, SOCK_STREAM, 0);
  if (fd == -1)
    {
      puts ("socket(0) failed");
      return 1;
    }
  int coe = fcntl (fd, F_GETFD);
  if (coe == -1)
    {
      puts ("fcntl failed");
      return 1;
    }
  if (coe & FD_CLOEXEC)
    {
      puts ("socket(0) set close-on-exec flag");
      return 1;
    }
  close (fd);

  fd = socket (PF_INET, SOCK_STREAM|SOCK_CLOEXEC, 0);
  if (fd == -1)
    {
      puts ("socket(SOCK_CLOEXEC) failed");
      return 1;
    }
  coe = fcntl (fd, F_GETFD);
  if (coe == -1)
    {
      puts ("fcntl failed");
      return 1;
    }
  if ((coe & FD_CLOEXEC) == 0)
    {
      puts ("socket(SOCK_CLOEXEC) does not set close-on-exec flag");
      return 1;
    }
  close (fd);

  int fds[2];
  if (socketpair (PF_UNIX, SOCK_STREAM, 0, fds) == -1)
    {
      puts ("socketpair(0) failed");
      return 1;
    }
  for (int i = 0; i < 2; ++i)
    {
      coe = fcntl (fds[i], F_GETFD);
      if (coe == -1)
        {
          puts ("fcntl failed");
          return 1;
        }
      if (coe & FD_CLOEXEC)
        {
          printf ("socketpair(0) set close-on-exec flag for fds[%d]\n", i);
          return 1;
        }
      close (fds[i]);
    }

  if (socketpair (PF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0, fds) == -1)
    {
      puts ("socketpair(SOCK_CLOEXEC) failed");
      return 1;
    }
  for (int i = 0; i < 2; ++i)
    {
      coe = fcntl (fds[i], F_GETFD);
      if (coe == -1)
        {
          puts ("fcntl failed");
          return 1;
        }
      if ((coe & FD_CLOEXEC) == 0)
        {
          printf ("socketpair(SOCK_CLOEXEC) does not set close-on-exec flag for fds[%d]\n", i);
          return 1;
        }
      close (fds[i]);
    }

  puts ("OK");

  return 0;
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/asm-mips/socket.h b/include/asm-mips/socket.h
index 63f60254d308741efde979586ccdd9456ac47811..facc2d7a87cafaa7220a842cdce0954f15bdd78c 100644 (file)
--- a/include/asm-mips/socket.h
+++ b/include/asm-mips/socket.h
@@ -102,6 +102,13 @@ enum sock_type {
 };
 
 #define SOCK_MAX (SOCK_PACKET + 1)
+/* Mask which covers at least up to SOCK_MASK-1.  The
+ *  * remaining bits are used as flags. */
+#define SOCK_TYPE_MASK 0xf
+
+/* Flags for socket, socketpair, paccept */
+#define SOCK_CLOEXEC   O_CLOEXEC
+#define SOCK_NONBLOCK  O_NONBLOCK
 
 #define ARCH_HAS_SOCKET_TYPES 1
 

diff --git a/include/linux/net.h b/include/linux/net.h
index 150a48c68d52b044ef2c40c7be8b3e81a3b99971..8b5383c45b456ec2f5cf4e142d4b20c1c9a563b2 100644 (file)
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -20,6 +20,7 @@
 
 #include <linux/wait.h>
 #include <linux/socket.h>
+#include <linux/fcntl.h>       /* For O_CLOEXEC */
 #include <asm/socket.h>
 
 struct poll_table_struct;
@@ -94,6 +95,12 @@ enum sock_type {
 };
 
 #define SOCK_MAX (SOCK_PACKET + 1)
+/* Mask which covers at least up to SOCK_MASK-1.  The
+ * remaining bits are used as flags. */
+#define SOCK_TYPE_MASK 0xf
+
+/* Flags for socket, socketpair, paccept */
+#define SOCK_CLOEXEC   O_CLOEXEC
 
 #endif /* ARCH_HAS_SOCKET_TYPES */
 
@@ -208,7 +215,7 @@ extern int               sock_sendmsg(struct socket *sock, struct msghdr *msg,
                                  size_t len);
 extern int          sock_recvmsg(struct socket *sock, struct msghdr *msg,
                                  size_t size, int flags);
-extern int          sock_map_fd(struct socket *sock);
+extern int          sock_map_fd(struct socket *sock, int flags);
 extern struct socket *sockfd_lookup(int fd, int *err);
 #define                     sockfd_put(sock) fput(sock->file)
 extern int          net_ratelimit(void);

diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index 4507f744f44e527cc140b6b5601e556c10bfd361..cdf137af7adc87d580280fbbce9b3c2d64b9dc82 100644 (file)
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -1285,7 +1285,7 @@ static int p9_socket_open(struct p9_trans *trans, struct socket *csocket)
        int fd, ret;
 
        csocket->sk->sk_allocation = GFP_NOIO;
-       fd = sock_map_fd(csocket);
+       fd = sock_map_fd(csocket, 0);
        if (fd < 0) {
                P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
                return fd;

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 79bece16aede7959948010158733bfaa21187df6..dbb79adf8f3c0bab606f7141e96ae96dd29b3e4c 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3910,7 +3910,7 @@ static int sctp_getsockopt_peeloff(struct sock *sk, int len, char __user *optval
                goto out;
 
        /* Map the socket to an unused fd that can be returned to the user.  */
-       retval = sock_map_fd(newsock);
+       retval = sock_map_fd(newsock, 0);
        if (retval < 0) {
                sock_release(newsock);
                goto out;

diff --git a/net/socket.c b/net/socket.c
index 1ba57d88898184160c8fd3c918eba73f3cd77d00..64601f900352ff90d9ccea0f0c9b436aa656b840 100644 (file)
--- a/net/socket.c
+++ b/net/socket.c
@@ -349,11 +349,11 @@ static struct dentry_operations sockfs_dentry_operations = {
  *     but we take care of internal coherence yet.
  */
 
-static int sock_alloc_fd(struct file **filep)
+static int sock_alloc_fd(struct file **filep, int flags)
 {
        int fd;
 
-       fd = get_unused_fd();
+       fd = get_unused_fd_flags(flags);
        if (likely(fd >= 0)) {
                struct file *file = get_empty_filp();
 
@@ -396,10 +396,10 @@ static int sock_attach_fd(struct socket *sock, struct file *file)
        return 0;
 }
 
-int sock_map_fd(struct socket *sock)
+int sock_map_fd(struct socket *sock, int flags)
 {
        struct file *newfile;
-       int fd = sock_alloc_fd(&newfile);
+       int fd = sock_alloc_fd(&newfile, flags);
 
        if (likely(fd >= 0)) {
                int err = sock_attach_fd(sock, newfile);
@@ -1218,12 +1218,18 @@ asmlinkage long sys_socket(int family, int type, int protocol)
 {
        int retval;
        struct socket *sock;
+       int flags;
+
+       flags = type & ~SOCK_TYPE_MASK;
+       if (flags & ~SOCK_CLOEXEC)
+               return -EINVAL;
+       type &= SOCK_TYPE_MASK;
 
        retval = sock_create(family, type, protocol, &sock);
        if (retval < 0)
                goto out;
 
-       retval = sock_map_fd(sock);
+       retval = sock_map_fd(sock, flags & O_CLOEXEC);
        if (retval < 0)
                goto out_release;
 
@@ -1246,6 +1252,12 @@ asmlinkage long sys_socketpair(int family, int type, int protocol,
        struct socket *sock1, *sock2;
        int fd1, fd2, err;
        struct file *newfile1, *newfile2;
+       int flags;
+
+       flags = type & ~SOCK_TYPE_MASK;
+       if (flags & ~SOCK_CLOEXEC)
+               return -EINVAL;
+       type &= SOCK_TYPE_MASK;
 
        /*
         * Obtain the first socket and check if the underlying protocol
@@ -1264,13 +1276,13 @@ asmlinkage long sys_socketpair(int family, int type, int protocol,
        if (err < 0)
                goto out_release_both;
 
-       fd1 = sock_alloc_fd(&newfile1);
+       fd1 = sock_alloc_fd(&newfile1, flags & O_CLOEXEC);
        if (unlikely(fd1 < 0)) {
                err = fd1;
                goto out_release_both;
        }
 
-       fd2 = sock_alloc_fd(&newfile2);
+       fd2 = sock_alloc_fd(&newfile2, flags & O_CLOEXEC);
        if (unlikely(fd2 < 0)) {
                err = fd2;
                put_filp(newfile1);
@@ -1426,7 +1438,7 @@ asmlinkage long sys_accept(int fd, struct sockaddr __user *upeer_sockaddr,
         */
        __module_get(newsock->ops->owner);
 
-       newfd = sock_alloc_fd(&newfile);
+       newfd = sock_alloc_fd(&newfile, 0);
        if (unlikely(newfd < 0)) {
                err = newfd;
                sock_release(newsock);