| Message ID | 20230411104231.160837-4-aleksandr.mikhalitsyn@canonical.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Add SCM_PIDFD and SO_PEERPIDFD | expand |
On Tue, Apr 11, 2023 at 12:42:30PM +0200, Alexander Mikhalitsyn wrote: > Add SO_PEERPIDFD which allows to get pidfd of peer socket holder pidfd. > This thing is direct analog of SO_PEERCRED which allows to get plain PID. > > Cc: "David S. Miller" <davem@davemloft.net> > Cc: Eric Dumazet <edumazet@google.com> > Cc: Jakub Kicinski <kuba@kernel.org> > Cc: Paolo Abeni <pabeni@redhat.com> > Cc: Leon Romanovsky <leon@kernel.org> > Cc: David Ahern <dsahern@kernel.org> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Kees Cook <keescook@chromium.org> > Cc: Christian Brauner <brauner@kernel.org> > Cc: Kuniyuki Iwashima <kuniyu@amazon.com> > Cc: Lennart Poettering <mzxreary@0pointer.de> > Cc: Luca Boccassi <bluca@debian.org> > Cc: linux-kernel@vger.kernel.org > Cc: netdev@vger.kernel.org > Cc: linux-arch@vger.kernel.org > Tested-by: Luca Boccassi <bluca@debian.org> > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> > --- > v3: > - fixed possible fd leak (thanks to Christian Brauner) > v2: > According to review comments from Kuniyuki Iwashima and Christian Brauner: > - use pidfd_create(..) retval as a result > - whitespace change > --- > arch/alpha/include/uapi/asm/socket.h | 1 + > arch/mips/include/uapi/asm/socket.h | 1 + > arch/parisc/include/uapi/asm/socket.h | 1 + > arch/sparc/include/uapi/asm/socket.h | 1 + > include/uapi/asm-generic/socket.h | 1 + > net/core/sock.c | 33 +++++++++++++++++++++++++ > net/socket.c | 7 ++++++ > tools/include/uapi/asm-generic/socket.h | 1 + > 8 files changed, 46 insertions(+) > > diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h > index ff310613ae64..e94f621903fe 100644 > --- a/arch/alpha/include/uapi/asm/socket.h > +++ b/arch/alpha/include/uapi/asm/socket.h > @@ -138,6 +138,7 @@ > #define SO_RCVMARK 75 > > #define SO_PASSPIDFD 76 > +#define SO_PEERPIDFD 77 > > #if !defined(__KERNEL__) > > diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h > index 762dcb80e4ec..60ebaed28a4c 100644 > --- a/arch/mips/include/uapi/asm/socket.h > +++ b/arch/mips/include/uapi/asm/socket.h > @@ -149,6 +149,7 @@ > #define SO_RCVMARK 75 > > #define SO_PASSPIDFD 76 > +#define SO_PEERPIDFD 77 > > #if !defined(__KERNEL__) > > diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h > index df16a3e16d64..be264c2b1a11 100644 > --- a/arch/parisc/include/uapi/asm/socket.h > +++ b/arch/parisc/include/uapi/asm/socket.h > @@ -130,6 +130,7 @@ > #define SO_RCVMARK 0x4049 > > #define SO_PASSPIDFD 0x404A > +#define SO_PEERPIDFD 0x404B > > #if !defined(__KERNEL__) > > diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h > index 6e2847804fea..682da3714686 100644 > --- a/arch/sparc/include/uapi/asm/socket.h > +++ b/arch/sparc/include/uapi/asm/socket.h > @@ -131,6 +131,7 @@ > #define SO_RCVMARK 0x0054 > > #define SO_PASSPIDFD 0x0055 > +#define SO_PEERPIDFD 0x0056 > > #if !defined(__KERNEL__) > > diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h > index b76169fdb80b..8ce8a39a1e5f 100644 > --- a/include/uapi/asm-generic/socket.h > +++ b/include/uapi/asm-generic/socket.h > @@ -133,6 +133,7 @@ > #define SO_RCVMARK 75 > > #define SO_PASSPIDFD 76 > +#define SO_PEERPIDFD 77 > > #if !defined(__KERNEL__) > > diff --git a/net/core/sock.c b/net/core/sock.c > index 3f974246ba3e..2b040a69e355 100644 > --- a/net/core/sock.c > +++ b/net/core/sock.c > @@ -1763,6 +1763,39 @@ int sk_getsockopt(struct sock *sk, int level, int optname, > goto lenout; > } > > + case SO_PEERPIDFD: > + { > + struct pid *peer_pid; > + struct file *pidfd_file = NULL; > + int pidfd; > + > + if (len > sizeof(pidfd)) > + len = sizeof(pidfd); > + > + spin_lock(&sk->sk_peer_lock); > + peer_pid = get_pid(sk->sk_peer_pid); > + spin_unlock(&sk->sk_peer_lock); > + > + pidfd = pidfd_prepare(peer_pid, 0, &pidfd_file); > + > + put_pid(peer_pid); Would be a bit nicer if this would be: pidfd = pidfd_prepare(peer_pid, 0, &pidfd_file); put_pid(peer_pid); if (pidfd < 0) return pidfd; if (copy_to_sockptr(optval, &pidfd, len) || copy_to_sockptr(optlen, &len, sizeof(int))) return -EFAULT; fd_install(pidfd, pidfd_file); return 0; Otherwise seems good enough to me. > + > + if (copy_to_sockptr(optval, &pidfd, len) || > + copy_to_sockptr(optlen, &len, sizeof(int))) { > + if (pidfd >= 0) { > + put_unused_fd(pidfd); > + fput(pidfd_file); > + } > + > + return -EFAULT; > + } > + > + if (pidfd_file) > + fd_install(pidfd, pidfd_file); > + > + return 0; > + } > + > case SO_PEERGROUPS: > { > const struct cred *cred; > diff --git a/net/socket.c b/net/socket.c > index 9c1ef11de23f..505b85489354 100644 > --- a/net/socket.c > +++ b/net/socket.c > @@ -2248,6 +2248,13 @@ static bool sockopt_installs_fd(int level, int optname) > default: > return false; > } > + } else if (level == SOL_SOCKET) { > + switch (optname) { > + case SO_PEERPIDFD: > + return true; > + default: > + return false; > + } > } > > return false; > diff --git a/tools/include/uapi/asm-generic/socket.h b/tools/include/uapi/asm-generic/socket.h > index fbbc4bf53ee3..54d9c8bf7c55 100644 > --- a/tools/include/uapi/asm-generic/socket.h > +++ b/tools/include/uapi/asm-generic/socket.h > @@ -122,6 +122,7 @@ > #define SO_RCVMARK 75 > > #define SO_PASSPIDFD 76 > +#define SO_PEERPIDFD 77 > > #if !defined(__KERNEL__) > > -- > 2.34.1 >
On Tue, Apr 11, 2023 at 5:57 PM Christian Brauner <brauner@kernel.org> wrote: > > On Tue, Apr 11, 2023 at 12:42:30PM +0200, Alexander Mikhalitsyn wrote: > > Add SO_PEERPIDFD which allows to get pidfd of peer socket holder pidfd. > > This thing is direct analog of SO_PEERCRED which allows to get plain PID. > > > > Cc: "David S. Miller" <davem@davemloft.net> > > Cc: Eric Dumazet <edumazet@google.com> > > Cc: Jakub Kicinski <kuba@kernel.org> > > Cc: Paolo Abeni <pabeni@redhat.com> > > Cc: Leon Romanovsky <leon@kernel.org> > > Cc: David Ahern <dsahern@kernel.org> > > Cc: Arnd Bergmann <arnd@arndb.de> > > Cc: Kees Cook <keescook@chromium.org> > > Cc: Christian Brauner <brauner@kernel.org> > > Cc: Kuniyuki Iwashima <kuniyu@amazon.com> > > Cc: Lennart Poettering <mzxreary@0pointer.de> > > Cc: Luca Boccassi <bluca@debian.org> > > Cc: linux-kernel@vger.kernel.org > > Cc: netdev@vger.kernel.org > > Cc: linux-arch@vger.kernel.org > > Tested-by: Luca Boccassi <bluca@debian.org> > > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> > > --- > > v3: > > - fixed possible fd leak (thanks to Christian Brauner) > > v2: > > According to review comments from Kuniyuki Iwashima and Christian Brauner: > > - use pidfd_create(..) retval as a result > > - whitespace change > > --- > > arch/alpha/include/uapi/asm/socket.h | 1 + > > arch/mips/include/uapi/asm/socket.h | 1 + > > arch/parisc/include/uapi/asm/socket.h | 1 + > > arch/sparc/include/uapi/asm/socket.h | 1 + > > include/uapi/asm-generic/socket.h | 1 + > > net/core/sock.c | 33 +++++++++++++++++++++++++ > > net/socket.c | 7 ++++++ > > tools/include/uapi/asm-generic/socket.h | 1 + > > 8 files changed, 46 insertions(+) > > > > diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h > > index ff310613ae64..e94f621903fe 100644 > > --- a/arch/alpha/include/uapi/asm/socket.h > > +++ b/arch/alpha/include/uapi/asm/socket.h > > @@ -138,6 +138,7 @@ > > #define SO_RCVMARK 75 > > > > #define SO_PASSPIDFD 76 > > +#define SO_PEERPIDFD 77 > > > > #if !defined(__KERNEL__) > > > > diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h > > index 762dcb80e4ec..60ebaed28a4c 100644 > > --- a/arch/mips/include/uapi/asm/socket.h > > +++ b/arch/mips/include/uapi/asm/socket.h > > @@ -149,6 +149,7 @@ > > #define SO_RCVMARK 75 > > > > #define SO_PASSPIDFD 76 > > +#define SO_PEERPIDFD 77 > > > > #if !defined(__KERNEL__) > > > > diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h > > index df16a3e16d64..be264c2b1a11 100644 > > --- a/arch/parisc/include/uapi/asm/socket.h > > +++ b/arch/parisc/include/uapi/asm/socket.h > > @@ -130,6 +130,7 @@ > > #define SO_RCVMARK 0x4049 > > > > #define SO_PASSPIDFD 0x404A > > +#define SO_PEERPIDFD 0x404B > > > > #if !defined(__KERNEL__) > > > > diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h > > index 6e2847804fea..682da3714686 100644 > > --- a/arch/sparc/include/uapi/asm/socket.h > > +++ b/arch/sparc/include/uapi/asm/socket.h > > @@ -131,6 +131,7 @@ > > #define SO_RCVMARK 0x0054 > > > > #define SO_PASSPIDFD 0x0055 > > +#define SO_PEERPIDFD 0x0056 > > > > #if !defined(__KERNEL__) > > > > diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h > > index b76169fdb80b..8ce8a39a1e5f 100644 > > --- a/include/uapi/asm-generic/socket.h > > +++ b/include/uapi/asm-generic/socket.h > > @@ -133,6 +133,7 @@ > > #define SO_RCVMARK 75 > > > > #define SO_PASSPIDFD 76 > > +#define SO_PEERPIDFD 77 > > > > #if !defined(__KERNEL__) > > > > diff --git a/net/core/sock.c b/net/core/sock.c > > index 3f974246ba3e..2b040a69e355 100644 > > --- a/net/core/sock.c > > +++ b/net/core/sock.c > > @@ -1763,6 +1763,39 @@ int sk_getsockopt(struct sock *sk, int level, int optname, > > goto lenout; > > } > > > > + case SO_PEERPIDFD: > > + { > > + struct pid *peer_pid; > > + struct file *pidfd_file = NULL; > > + int pidfd; > > + > > + if (len > sizeof(pidfd)) > > + len = sizeof(pidfd); > > + > > + spin_lock(&sk->sk_peer_lock); > > + peer_pid = get_pid(sk->sk_peer_pid); > > + spin_unlock(&sk->sk_peer_lock); > > + > > + pidfd = pidfd_prepare(peer_pid, 0, &pidfd_file); > > + > > + put_pid(peer_pid); > > Would be a bit nicer if this would be: > > pidfd = pidfd_prepare(peer_pid, 0, &pidfd_file); > put_pid(peer_pid); > if (pidfd < 0) > return pidfd; > if (copy_to_sockptr(optval, &pidfd, len) || > copy_to_sockptr(optlen, &len, sizeof(int))) { put_unused_fd(pidfd); fput(pidfd_file); are still needed there, right? > return -EFAULT; } > > fd_install(pidfd, pidfd_file); > return 0; > > Otherwise seems good enough to me. Will do. > > > + > > + if (copy_to_sockptr(optval, &pidfd, len) || > > + copy_to_sockptr(optlen, &len, sizeof(int))) { > > + if (pidfd >= 0) { > > + put_unused_fd(pidfd); > > + fput(pidfd_file); > > + } > > + > > + return -EFAULT; > > + } > > + > > + if (pidfd_file) > > + fd_install(pidfd, pidfd_file); > > + > > + return 0; > > + } > > + > > case SO_PEERGROUPS: > > { > > const struct cred *cred; > > diff --git a/net/socket.c b/net/socket.c > > index 9c1ef11de23f..505b85489354 100644 > > --- a/net/socket.c > > +++ b/net/socket.c > > @@ -2248,6 +2248,13 @@ static bool sockopt_installs_fd(int level, int optname) > > default: > > return false; > > } > > + } else if (level == SOL_SOCKET) { > > + switch (optname) { > > + case SO_PEERPIDFD: > > + return true; > > + default: > > + return false; > > + } > > } > > > > return false; > > diff --git a/tools/include/uapi/asm-generic/socket.h b/tools/include/uapi/asm-generic/socket.h > > index fbbc4bf53ee3..54d9c8bf7c55 100644 > > --- a/tools/include/uapi/asm-generic/socket.h > > +++ b/tools/include/uapi/asm-generic/socket.h > > @@ -122,6 +122,7 @@ > > #define SO_RCVMARK 75 > > > > #define SO_PASSPIDFD 76 > > +#define SO_PEERPIDFD 77 > > > > #if !defined(__KERNEL__) > > > > -- > > 2.34.1 > >
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h index ff310613ae64..e94f621903fe 100644 --- a/arch/alpha/include/uapi/asm/socket.h +++ b/arch/alpha/include/uapi/asm/socket.h @@ -138,6 +138,7 @@ #define SO_RCVMARK 75 #define SO_PASSPIDFD 76 +#define SO_PEERPIDFD 77 #if !defined(__KERNEL__) diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h index 762dcb80e4ec..60ebaed28a4c 100644 --- a/arch/mips/include/uapi/asm/socket.h +++ b/arch/mips/include/uapi/asm/socket.h @@ -149,6 +149,7 @@ #define SO_RCVMARK 75 #define SO_PASSPIDFD 76 +#define SO_PEERPIDFD 77 #if !defined(__KERNEL__) diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h index df16a3e16d64..be264c2b1a11 100644 --- a/arch/parisc/include/uapi/asm/socket.h +++ b/arch/parisc/include/uapi/asm/socket.h @@ -130,6 +130,7 @@ #define SO_RCVMARK 0x4049 #define SO_PASSPIDFD 0x404A +#define SO_PEERPIDFD 0x404B #if !defined(__KERNEL__) diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h index 6e2847804fea..682da3714686 100644 --- a/arch/sparc/include/uapi/asm/socket.h +++ b/arch/sparc/include/uapi/asm/socket.h @@ -131,6 +131,7 @@ #define SO_RCVMARK 0x0054 #define SO_PASSPIDFD 0x0055 +#define SO_PEERPIDFD 0x0056 #if !defined(__KERNEL__) diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h index b76169fdb80b..8ce8a39a1e5f 100644 --- a/include/uapi/asm-generic/socket.h +++ b/include/uapi/asm-generic/socket.h @@ -133,6 +133,7 @@ #define SO_RCVMARK 75 #define SO_PASSPIDFD 76 +#define SO_PEERPIDFD 77 #if !defined(__KERNEL__) diff --git a/net/core/sock.c b/net/core/sock.c index 3f974246ba3e..2b040a69e355 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1763,6 +1763,39 @@ int sk_getsockopt(struct sock *sk, int level, int optname, goto lenout; } + case SO_PEERPIDFD: + { + struct pid *peer_pid; + struct file *pidfd_file = NULL; + int pidfd; + + if (len > sizeof(pidfd)) + len = sizeof(pidfd); + + spin_lock(&sk->sk_peer_lock); + peer_pid = get_pid(sk->sk_peer_pid); + spin_unlock(&sk->sk_peer_lock); + + pidfd = pidfd_prepare(peer_pid, 0, &pidfd_file); + + put_pid(peer_pid); + + if (copy_to_sockptr(optval, &pidfd, len) || + copy_to_sockptr(optlen, &len, sizeof(int))) { + if (pidfd >= 0) { + put_unused_fd(pidfd); + fput(pidfd_file); + } + + return -EFAULT; + } + + if (pidfd_file) + fd_install(pidfd, pidfd_file); + + return 0; + } + case SO_PEERGROUPS: { const struct cred *cred; diff --git a/net/socket.c b/net/socket.c index 9c1ef11de23f..505b85489354 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2248,6 +2248,13 @@ static bool sockopt_installs_fd(int level, int optname) default: return false; } + } else if (level == SOL_SOCKET) { + switch (optname) { + case SO_PEERPIDFD: + return true; + default: + return false; + } } return false; diff --git a/tools/include/uapi/asm-generic/socket.h b/tools/include/uapi/asm-generic/socket.h index fbbc4bf53ee3..54d9c8bf7c55 100644 --- a/tools/include/uapi/asm-generic/socket.h +++ b/tools/include/uapi/asm-generic/socket.h @@ -122,6 +122,7 @@ #define SO_RCVMARK 75 #define SO_PASSPIDFD 76 +#define SO_PEERPIDFD 77 #if !defined(__KERNEL__)