| Message ID | 20230608202628.837772-2-aleksandr.mikhalitsyn@canonical.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 5e2ff6704a275be009be8979af17c52361b79b89 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Add SCM_PIDFD and SO_PEERPIDFD | expand |
On Thu, Jun 8, 2023 at 10:26 PM Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> wrote: > > Implement SCM_PIDFD, a new type of CMSG type analogical to SCM_CREDENTIALS, > but it contains pidfd instead of plain pid, which allows programmers not > to care about PID reuse problem. > > We mask SO_PASSPIDFD feature if CONFIG_UNIX is not builtin because > it depends on a pidfd_prepare() API which is not exported to the kernel > modules. > > Idea comes from UAPI kernel group: > https://uapi-group.org/kernel-features/ > > Big thanks to Christian Brauner and Lennart Poettering for productive > discussions about this. > > 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> > Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> > Reviewed-by: Christian Brauner <brauner@kernel.org> > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> > --- Reviewed-by: Eric Dumazet <edumazet@google.com>
On Mon, Jun 12, 2023 at 11:19 AM Eric Dumazet <edumazet@google.com> wrote: > > On Thu, Jun 8, 2023 at 10:26 PM Alexander Mikhalitsyn > <aleksandr.mikhalitsyn@canonical.com> wrote: > > > > Implement SCM_PIDFD, a new type of CMSG type analogical to SCM_CREDENTIALS, > > but it contains pidfd instead of plain pid, which allows programmers not > > to care about PID reuse problem. > > > > We mask SO_PASSPIDFD feature if CONFIG_UNIX is not builtin because > > it depends on a pidfd_prepare() API which is not exported to the kernel > > modules. > > > > Idea comes from UAPI kernel group: > > https://uapi-group.org/kernel-features/ > > > > Big thanks to Christian Brauner and Lennart Poettering for productive > > discussions about this. > > > > 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> > > Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> > > Reviewed-by: Christian Brauner <brauner@kernel.org> > > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> > > --- > > Reviewed-by: Eric Dumazet <edumazet@google.com> Thanks, Eric! Kind regards, Alex
On Thu, Jun 08, 2023 at 10:26:25PM +0200, Alexander Mikhalitsyn wrote: > Implement SCM_PIDFD, a new type of CMSG type analogical to SCM_CREDENTIALS, > but it contains pidfd instead of plain pid, which allows programmers not > to care about PID reuse problem. > > We mask SO_PASSPIDFD feature if CONFIG_UNIX is not builtin because > it depends on a pidfd_prepare() API which is not exported to the kernel > modules. > > Idea comes from UAPI kernel group: > https://uapi-group.org/kernel-features/ > > Big thanks to Christian Brauner and Lennart Poettering for productive > discussions about this. > > 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> > Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> > Reviewed-by: Christian Brauner <brauner@kernel.org> > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> > --- > arch/alpha/include/uapi/asm/socket.h | 2 ++ > arch/mips/include/uapi/asm/socket.h | 2 ++ > arch/parisc/include/uapi/asm/socket.h | 2 ++ > arch/sparc/include/uapi/asm/socket.h | 2 ++ > include/linux/net.h | 1 + > include/linux/socket.h | 1 + > include/net/scm.h | 39 +++++++++++++++++++++++-- > include/uapi/asm-generic/socket.h | 2 ++ > net/core/sock.c | 11 +++++++ > net/mptcp/sockopt.c | 1 + > net/unix/af_unix.c | 18 ++++++++---- > tools/include/uapi/asm-generic/socket.h | 2 ++ > 12 files changed, 76 insertions(+), 7 deletions(-) ... > +static __inline__ void scm_pidfd_recv(struct msghdr *msg, struct scm_cookie *scm) > +{ > + struct file *pidfd_file = NULL; > + int pidfd; > + > + /* > + * put_cmsg() doesn't return an error if CMSG is truncated, > + * that's why we need to opencode these checks here. > + */ > + if ((msg->msg_controllen <= sizeof(struct cmsghdr)) || > + (msg->msg_controllen - sizeof(struct cmsghdr)) < sizeof(int)) { > + msg->msg_flags |= MSG_CTRUNC; > + return; > + } This does not work for compat tasks since the size of struct cmsghdr (aka struct compat_cmsghdr) is differently. If the check from put_cmsg() is open-coded here, then also a different check for compat tasks needs to be added. Discovered this because I was wondering why strace compat tests fail; it seems because of this. See https://github.com/strace/strace/blob/master/tests/scm_pidfd.c For compat tasks recvmsg() returns with msg_flags=MSG_CTRUNC since the above code expects a larger buffer than is necessary.
From: Heiko Carstens <hca@linux.ibm.com> Date: Fri, 1 Sep 2023 22:05:17 +0200 > On Thu, Jun 08, 2023 at 10:26:25PM +0200, Alexander Mikhalitsyn wrote: > > Implement SCM_PIDFD, a new type of CMSG type analogical to SCM_CREDENTIALS, > > but it contains pidfd instead of plain pid, which allows programmers not > > to care about PID reuse problem. > > > > We mask SO_PASSPIDFD feature if CONFIG_UNIX is not builtin because > > it depends on a pidfd_prepare() API which is not exported to the kernel > > modules. > > > > Idea comes from UAPI kernel group: > > https://uapi-group.org/kernel-features/ > > > > Big thanks to Christian Brauner and Lennart Poettering for productive > > discussions about this. > > > > 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> > > Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> > > Reviewed-by: Christian Brauner <brauner@kernel.org> > > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> > > --- > > arch/alpha/include/uapi/asm/socket.h | 2 ++ > > arch/mips/include/uapi/asm/socket.h | 2 ++ > > arch/parisc/include/uapi/asm/socket.h | 2 ++ > > arch/sparc/include/uapi/asm/socket.h | 2 ++ > > include/linux/net.h | 1 + > > include/linux/socket.h | 1 + > > include/net/scm.h | 39 +++++++++++++++++++++++-- > > include/uapi/asm-generic/socket.h | 2 ++ > > net/core/sock.c | 11 +++++++ > > net/mptcp/sockopt.c | 1 + > > net/unix/af_unix.c | 18 ++++++++---- > > tools/include/uapi/asm-generic/socket.h | 2 ++ > > 12 files changed, 76 insertions(+), 7 deletions(-) > ... > > +static __inline__ void scm_pidfd_recv(struct msghdr *msg, struct scm_cookie *scm) > > +{ > > + struct file *pidfd_file = NULL; > > + int pidfd; > > + > > + /* > > + * put_cmsg() doesn't return an error if CMSG is truncated, > > + * that's why we need to opencode these checks here. > > + */ > > + if ((msg->msg_controllen <= sizeof(struct cmsghdr)) || > > + (msg->msg_controllen - sizeof(struct cmsghdr)) < sizeof(int)) { > > + msg->msg_flags |= MSG_CTRUNC; > > + return; > > + } > > This does not work for compat tasks since the size of struct cmsghdr (aka > struct compat_cmsghdr) is differently. If the check from put_cmsg() is > open-coded here, then also a different check for compat tasks needs to be > added. > > Discovered this because I was wondering why strace compat tests fail; it > seems because of this. > > See https://github.com/strace/strace/blob/master/tests/scm_pidfd.c > > For compat tasks recvmsg() returns with msg_flags=MSG_CTRUNC since the > above code expects a larger buffer than is necessary. Can you test this ? ---8<--- diff --git a/include/net/scm.h b/include/net/scm.h index c5bcdf65f55c..099497ce4aee 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -9,6 +9,7 @@ #include <linux/pid.h> #include <linux/nsproxy.h> #include <linux/sched/signal.h> +#include <net/compat.h> /* Well, we should have at least one descriptor open * to accept passed FDs 8) @@ -125,14 +126,19 @@ static __inline__ void scm_pidfd_recv(struct msghdr *msg, struct scm_cookie *scm struct file *pidfd_file = NULL; int pidfd; - /* - * put_cmsg() doesn't return an error if CMSG is truncated, + /* put_cmsg() doesn't return an error if CMSG is truncated, * that's why we need to opencode these checks here. */ - if ((msg->msg_controllen <= sizeof(struct cmsghdr)) || - (msg->msg_controllen - sizeof(struct cmsghdr)) < sizeof(int)) { - msg->msg_flags |= MSG_CTRUNC; - return; + if (msg->msg_flags & MSG_CMSG_COMPAT) { + if (msg->msg_controllen < sizeof(struct compat_cmsghdr) + sizeof(int)) { + msg->msg_flags |= MSG_CTRUNC; + return; + } + } else { + if (msg->msg_controllen < sizeof(struct cmsghdr) + sizeof(int)) { + msg->msg_flags |= MSG_CTRUNC; + return; + } } if (!scm->pid) ---8<---
On Fri, Sep 01, 2023 at 01:33:22PM -0700, Kuniyuki Iwashima wrote: > From: Heiko Carstens <hca@linux.ibm.com> > Date: Fri, 1 Sep 2023 22:05:17 +0200 > > On Thu, Jun 08, 2023 at 10:26:25PM +0200, Alexander Mikhalitsyn wrote: > > > + if ((msg->msg_controllen <= sizeof(struct cmsghdr)) || > > > + (msg->msg_controllen - sizeof(struct cmsghdr)) < sizeof(int)) { > > > + msg->msg_flags |= MSG_CTRUNC; > > > + return; > > > + } > > > > This does not work for compat tasks since the size of struct cmsghdr (aka > > struct compat_cmsghdr) is differently. If the check from put_cmsg() is > > open-coded here, then also a different check for compat tasks needs to be > > added. > > > > Discovered this because I was wondering why strace compat tests fail; it > > seems because of this. > > > > See https://github.com/strace/strace/blob/master/tests/scm_pidfd.c > > > > For compat tasks recvmsg() returns with msg_flags=MSG_CTRUNC since the > > above code expects a larger buffer than is necessary. > > Can you test this ? Works for me. Tested-by: Heiko Carstens <hca@linux.ibm.com>
From: Heiko Carstens <hca@linux.ibm.com> Date: Fri, 1 Sep 2023 22:51:45 +0200 > On Fri, Sep 01, 2023 at 01:33:22PM -0700, Kuniyuki Iwashima wrote: > > From: Heiko Carstens <hca@linux.ibm.com> > > Date: Fri, 1 Sep 2023 22:05:17 +0200 > > > On Thu, Jun 08, 2023 at 10:26:25PM +0200, Alexander Mikhalitsyn wrote: > > > > + if ((msg->msg_controllen <= sizeof(struct cmsghdr)) || > > > > + (msg->msg_controllen - sizeof(struct cmsghdr)) < sizeof(int)) { > > > > + msg->msg_flags |= MSG_CTRUNC; > > > > + return; > > > > + } > > > > > > This does not work for compat tasks since the size of struct cmsghdr (aka > > > struct compat_cmsghdr) is differently. If the check from put_cmsg() is > > > open-coded here, then also a different check for compat tasks needs to be > > > added. > > > > > > Discovered this because I was wondering why strace compat tests fail; it > > > seems because of this. > > > > > > See https://github.com/strace/strace/blob/master/tests/scm_pidfd.c > > > > > > For compat tasks recvmsg() returns with msg_flags=MSG_CTRUNC since the > > > above code expects a larger buffer than is necessary. > > > > Can you test this ? > > Works for me. > > Tested-by: Heiko Carstens <hca@linux.ibm.com> Thanks! I'll post a formal patch.
On Fri, Sep 1, 2023 at 10:56 PM Kuniyuki Iwashima <kuniyu@amazon.com> wrote: > > From: Heiko Carstens <hca@linux.ibm.com> > Date: Fri, 1 Sep 2023 22:51:45 +0200 > > On Fri, Sep 01, 2023 at 01:33:22PM -0700, Kuniyuki Iwashima wrote: > > > From: Heiko Carstens <hca@linux.ibm.com> > > > Date: Fri, 1 Sep 2023 22:05:17 +0200 > > > > On Thu, Jun 08, 2023 at 10:26:25PM +0200, Alexander Mikhalitsyn wrote: > > > > > + if ((msg->msg_controllen <= sizeof(struct cmsghdr)) || > > > > > + (msg->msg_controllen - sizeof(struct cmsghdr)) < sizeof(int)) { > > > > > + msg->msg_flags |= MSG_CTRUNC; > > > > > + return; > > > > > + } > > > > > > > > This does not work for compat tasks since the size of struct cmsghdr (aka > > > > struct compat_cmsghdr) is differently. If the check from put_cmsg() is > > > > open-coded here, then also a different check for compat tasks needs to be > > > > added. > > > > > > > > Discovered this because I was wondering why strace compat tests fail; it > > > > seems because of this. > > > > > > > > See https://github.com/strace/strace/blob/master/tests/scm_pidfd.c > > > > > > > > For compat tasks recvmsg() returns with msg_flags=MSG_CTRUNC since the > > > > above code expects a larger buffer than is necessary. > > > > > > Can you test this ? > > > > Works for me. > > > > Tested-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Thanks for reporting this, Heiko! My bad. Kuniyuki, Thanks for the quick fix. Kind regards, Alex > > Thanks! > I'll post a formal patch.
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h index 739891b94136..ff310613ae64 100644 --- a/arch/alpha/include/uapi/asm/socket.h +++ b/arch/alpha/include/uapi/asm/socket.h @@ -137,6 +137,8 @@ #define SO_RCVMARK 75 +#define SO_PASSPIDFD 76 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h index 18f3d95ecfec..762dcb80e4ec 100644 --- a/arch/mips/include/uapi/asm/socket.h +++ b/arch/mips/include/uapi/asm/socket.h @@ -148,6 +148,8 @@ #define SO_RCVMARK 75 +#define SO_PASSPIDFD 76 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h index f486d3dfb6bb..df16a3e16d64 100644 --- a/arch/parisc/include/uapi/asm/socket.h +++ b/arch/parisc/include/uapi/asm/socket.h @@ -129,6 +129,8 @@ #define SO_RCVMARK 0x4049 +#define SO_PASSPIDFD 0x404A + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h index 2fda57a3ea86..6e2847804fea 100644 --- a/arch/sparc/include/uapi/asm/socket.h +++ b/arch/sparc/include/uapi/asm/socket.h @@ -130,6 +130,8 @@ #define SO_RCVMARK 0x0054 +#define SO_PASSPIDFD 0x0055 + #if !defined(__KERNEL__) diff --git a/include/linux/net.h b/include/linux/net.h index b73ad8e3c212..c234dfbe7a30 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -43,6 +43,7 @@ struct net; #define SOCK_PASSSEC 4 #define SOCK_SUPPORT_ZC 5 #define SOCK_CUSTOM_SOCKOPT 6 +#define SOCK_PASSPIDFD 7 #ifndef ARCH_HAS_SOCKET_TYPES /** diff --git a/include/linux/socket.h b/include/linux/socket.h index bd1cc3238851..3451a08f70d1 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -177,6 +177,7 @@ static inline size_t msg_data_left(struct msghdr *msg) #define SCM_RIGHTS 0x01 /* rw: access rights (array of int) */ #define SCM_CREDENTIALS 0x02 /* rw: struct ucred */ #define SCM_SECURITY 0x03 /* rw: security label */ +#define SCM_PIDFD 0x04 /* ro: pidfd (int) */ struct ucred { __u32 pid; diff --git a/include/net/scm.h b/include/net/scm.h index 585adc1346bd..c67f765a165b 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -120,12 +120,44 @@ static inline bool scm_has_secdata(struct socket *sock) } #endif /* CONFIG_SECURITY_NETWORK */ +static __inline__ void scm_pidfd_recv(struct msghdr *msg, struct scm_cookie *scm) +{ + struct file *pidfd_file = NULL; + int pidfd; + + /* + * put_cmsg() doesn't return an error if CMSG is truncated, + * that's why we need to opencode these checks here. + */ + if ((msg->msg_controllen <= sizeof(struct cmsghdr)) || + (msg->msg_controllen - sizeof(struct cmsghdr)) < sizeof(int)) { + msg->msg_flags |= MSG_CTRUNC; + return; + } + + WARN_ON_ONCE(!scm->pid); + pidfd = pidfd_prepare(scm->pid, 0, &pidfd_file); + + if (put_cmsg(msg, SOL_SOCKET, SCM_PIDFD, sizeof(int), &pidfd)) { + if (pidfd_file) { + put_unused_fd(pidfd); + fput(pidfd_file); + } + + return; + } + + if (pidfd_file) + fd_install(pidfd, pidfd_file); +} + static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm, int flags) { if (!msg->msg_control) { - if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp || - scm_has_secdata(sock)) + if (test_bit(SOCK_PASSCRED, &sock->flags) || + test_bit(SOCK_PASSPIDFD, &sock->flags) || + scm->fp || scm_has_secdata(sock)) msg->msg_flags |= MSG_CTRUNC; scm_destroy(scm); return; @@ -141,6 +173,9 @@ static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg, put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(ucreds), &ucreds); } + if (test_bit(SOCK_PASSPIDFD, &sock->flags)) + scm_pidfd_recv(msg, scm); + scm_destroy_cred(scm); scm_passec(sock, msg, scm); diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h index 638230899e98..b76169fdb80b 100644 --- a/include/uapi/asm-generic/socket.h +++ b/include/uapi/asm-generic/socket.h @@ -132,6 +132,8 @@ #define SO_RCVMARK 75 +#define SO_PASSPIDFD 76 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__)) diff --git a/net/core/sock.c b/net/core/sock.c index 24f2761bdb1d..ed4eb4ba738b 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1246,6 +1246,13 @@ int sk_setsockopt(struct sock *sk, int level, int optname, clear_bit(SOCK_PASSCRED, &sock->flags); break; + case SO_PASSPIDFD: + if (valbool) + set_bit(SOCK_PASSPIDFD, &sock->flags); + else + clear_bit(SOCK_PASSPIDFD, &sock->flags); + break; + case SO_TIMESTAMP_OLD: case SO_TIMESTAMP_NEW: case SO_TIMESTAMPNS_OLD: @@ -1732,6 +1739,10 @@ int sk_getsockopt(struct sock *sk, int level, int optname, v.val = !!test_bit(SOCK_PASSCRED, &sock->flags); break; + case SO_PASSPIDFD: + v.val = !!test_bit(SOCK_PASSPIDFD, &sock->flags); + break; + case SO_PEERCRED: { struct ucred peercred; diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index d4258869ac48..e172a5848b0d 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -355,6 +355,7 @@ static int mptcp_setsockopt_sol_socket(struct mptcp_sock *msk, int optname, case SO_BROADCAST: case SO_BSDCOMPAT: case SO_PASSCRED: + case SO_PASSPIDFD: case SO_PASSSEC: case SO_RXQ_OVFL: case SO_WIFI_STATUS: diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 653136d68b32..c46c2f5d860c 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1361,7 +1361,8 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, if (err) goto out; - if (test_bit(SOCK_PASSCRED, &sock->flags) && + if ((test_bit(SOCK_PASSCRED, &sock->flags) || + test_bit(SOCK_PASSPIDFD, &sock->flags)) && !unix_sk(sk)->addr) { err = unix_autobind(sk); if (err) @@ -1469,7 +1470,8 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, if (err) goto out; - if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr) { + if ((test_bit(SOCK_PASSCRED, &sock->flags) || + test_bit(SOCK_PASSPIDFD, &sock->flags)) && !u->addr) { err = unix_autobind(sk); if (err) goto out; @@ -1670,6 +1672,8 @@ static void unix_sock_inherit_flags(const struct socket *old, { if (test_bit(SOCK_PASSCRED, &old->flags)) set_bit(SOCK_PASSCRED, &new->flags); + if (test_bit(SOCK_PASSPIDFD, &old->flags)) + set_bit(SOCK_PASSPIDFD, &new->flags); if (test_bit(SOCK_PASSSEC, &old->flags)) set_bit(SOCK_PASSSEC, &new->flags); } @@ -1819,8 +1823,10 @@ static bool unix_passcred_enabled(const struct socket *sock, const struct sock *other) { return test_bit(SOCK_PASSCRED, &sock->flags) || + test_bit(SOCK_PASSPIDFD, &sock->flags) || !other->sk_socket || - test_bit(SOCK_PASSCRED, &other->sk_socket->flags); + test_bit(SOCK_PASSCRED, &other->sk_socket->flags) || + test_bit(SOCK_PASSPIDFD, &other->sk_socket->flags); } /* @@ -1904,7 +1910,8 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg, goto out; } - if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr) { + if ((test_bit(SOCK_PASSCRED, &sock->flags) || + test_bit(SOCK_PASSPIDFD, &sock->flags)) && !u->addr) { err = unix_autobind(sk); if (err) goto out; @@ -2718,7 +2725,8 @@ static int unix_stream_read_generic(struct unix_stream_read_state *state, /* Never glue messages from different writers */ if (!unix_skb_scm_eq(skb, &scm)) break; - } else if (test_bit(SOCK_PASSCRED, &sock->flags)) { + } else if (test_bit(SOCK_PASSCRED, &sock->flags) || + test_bit(SOCK_PASSPIDFD, &sock->flags)) { /* Copy credentials */ scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid); unix_set_secdata(&scm, skb); diff --git a/tools/include/uapi/asm-generic/socket.h b/tools/include/uapi/asm-generic/socket.h index 8756df13be50..fbbc4bf53ee3 100644 --- a/tools/include/uapi/asm-generic/socket.h +++ b/tools/include/uapi/asm-generic/socket.h @@ -121,6 +121,8 @@ #define SO_RCVMARK 75 +#define SO_PASSPIDFD 76 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__))