Re: [patch 1/2][RFC] add socketat syscall

["Michael Kerrisk" <mtk.manpages-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>]

> On Fri, Oct 31, 2008 at 4:56 PM, Daniel Lezcano <dlezcano-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org> wrote:
>> This patch adds the socketat syscall which allows to specify in
>> which network namespace we want to create a socket. The network
>> namespace destination is referred by a socket fd previously opened
>> in the destination network namespace.

Daniel,

Is there any documentation for this system call, and/or test programs?

Cheers,

Michael

>> Signed-off-by: Daniel Lezcano <dlezcano-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org>
>> ---
>>  arch/x86/include/asm/unistd_32.h   |    1
>>  arch/x86/include/asm/unistd_64.h   |    3 +-
>>  arch/x86/kernel/syscall_table_32.S |    1
>>  include/linux/syscalls.h           |    1
>>  kernel/sys_ni.c                    |    1
>>  net/socket.c                       |   45 +++++++++++++++++++++++++++++++++++++
>>  6 files changed, 51 insertions(+), 1 deletion(-)
>>
>> Index: net-next-2.6/arch/x86/include/asm/unistd_32.h
>> ===================================================================
>> --- net-next-2.6.orig/arch/x86/include/asm/unistd_32.h
>> +++ net-next-2.6/arch/x86/include/asm/unistd_32.h
>> @@ -338,6 +338,7 @@
>>  #define __NR_dup3              330
>>  #define __NR_pipe2             331
>>  #define __NR_inotify_init1     332
>> +#define __NR_socketat           333
>>
>>  #ifdef __KERNEL__
>>
>> Index: net-next-2.6/arch/x86/include/asm/unistd_64.h
>> ===================================================================
>> --- net-next-2.6.orig/arch/x86/include/asm/unistd_64.h
>> +++ net-next-2.6/arch/x86/include/asm/unistd_64.h
>> @@ -653,7 +653,8 @@ __SYSCALL(__NR_dup3, sys_dup3)
>>  __SYSCALL(__NR_pipe2, sys_pipe2)
>>  #define __NR_inotify_init1                     294
>>  __SYSCALL(__NR_inotify_init1, sys_inotify_init1)
>> -
>> +#define __NR_socketat                           295
>> +__SYSCALL(__NR_socketat, sys_socketat)
>>
>>  #ifndef __NO_STUBS
>>  #define __ARCH_WANT_OLD_READDIR
>> Index: net-next-2.6/arch/x86/kernel/syscall_table_32.S
>> ===================================================================
>> --- net-next-2.6.orig/arch/x86/kernel/syscall_table_32.S
>> +++ net-next-2.6/arch/x86/kernel/syscall_table_32.S
>> @@ -332,3 +332,4 @@ ENTRY(sys_call_table)
>>        .long sys_dup3                  /* 330 */
>>        .long sys_pipe2
>>        .long sys_inotify_init1
>> +       .long sys_socketat
>> Index: net-next-2.6/net/socket.c
>> ===================================================================
>> --- net-next-2.6.orig/net/socket.c
>> +++ net-next-2.6/net/socket.c
>> @@ -1253,6 +1253,51 @@ out_release:
>>        return retval;
>>  }
>>
>> +asmlinkage long sys_socketat(int fd, int family, int type, int protocol)
>> +{
>> +       int retval, fput_needed;
>> +       struct socket *sock;
>> +       struct socket *sockat;
>> +       struct net *net;
>> +       int flags;
>> +
>> +       /* Check the SOCK_* constants for consistency.  */
>> +       BUILD_BUG_ON(SOCK_CLOEXEC != O_CLOEXEC);
>> +       BUILD_BUG_ON((SOCK_MAX | SOCK_TYPE_MASK) != SOCK_TYPE_MASK);
>> +       BUILD_BUG_ON(SOCK_CLOEXEC & SOCK_TYPE_MASK);
>> +       BUILD_BUG_ON(SOCK_NONBLOCK & SOCK_TYPE_MASK);
>> +
>> +       flags = type & ~SOCK_TYPE_MASK;
>> +       if (flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
>> +               return -EINVAL;
>> +       type &= SOCK_TYPE_MASK;
>> +
>> +       if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))
>> +               flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
>> +
>> +       sock = sockfd_lookup_light(fd, &retval, &fput_needed);
>> +       if (!sock)
>> +               goto out;
>> +
>> +       net = sock_net(sock->sk);
>> +
>> +       retval = __sock_create(net, family, type, protocol, &sockat, 0);
>> +       if (retval)
>> +               goto out_fput;
>> +
>> +       retval = sock_map_fd(sock, flags & (O_CLOEXEC | O_NONBLOCK));
>> +       if (retval < 0)
>> +               goto out_release;
>> +out_fput:
>> +       fput_light(sock->file, fput_needed);
>> +out:
>> +       return retval;
>> +
>> +out_release:
>> +       sock_release(sockat);
>> +       goto out;
>> +}
>> +
>>  /*
>>  *     Create a pair of connected sockets.
>>  */
>> Index: net-next-2.6/include/linux/syscalls.h
>> ===================================================================
>> --- net-next-2.6.orig/include/linux/syscalls.h
>> +++ net-next-2.6/include/linux/syscalls.h
>> @@ -423,6 +423,7 @@ asmlinkage long sys_recvfrom(int, void _
>>                                struct sockaddr __user *, int __user *);
>>  asmlinkage long sys_recvmsg(int fd, struct msghdr __user *msg, unsigned flags);
>>  asmlinkage long sys_socket(int, int, int);
>> +asmlinkage long sys_socketat(int, int, int, int);
>>  asmlinkage long sys_socketpair(int, int, int, int __user *);
>>  asmlinkage long sys_socketcall(int call, unsigned long __user *args);
>>  asmlinkage long sys_listen(int, int);
>> Index: net-next-2.6/kernel/sys_ni.c
>> ===================================================================
>> --- net-next-2.6.orig/kernel/sys_ni.c
>> +++ net-next-2.6/kernel/sys_ni.c
>> @@ -40,6 +40,7 @@ cond_syscall(sys_send);
>>  cond_syscall(sys_recvfrom);
>>  cond_syscall(sys_recv);
>>  cond_syscall(sys_socket);
>> +cond_syscall(sys_socketat);
>>  cond_syscall(sys_setsockopt);
>>  cond_syscall(compat_sys_setsockopt);
>>  cond_syscall(sys_getsockopt);
>>
>> --
>> _______________________________________________
>> Containers mailing list
>> Containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
>> https://lists.linux-foundation.org/mailman/listinfo/containers
>>
>
>
>
> --
> Michael Kerrisk Linux man-pages maintainer;
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-- 
Michael Kerrisk
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git://git.kernel.org/pub/scm/docs/man-pages/man-pages.git
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