diff options
Diffstat (limited to 'sys/kern/uipc_usrreq.c')
| -rw-r--r-- | sys/kern/uipc_usrreq.c | 235 |
1 files changed, 181 insertions, 54 deletions
diff --git a/sys/kern/uipc_usrreq.c b/sys/kern/uipc_usrreq.c index 372a473a75c..0710393d376 100644 --- a/sys/kern/uipc_usrreq.c +++ b/sys/kern/uipc_usrreq.c @@ -1,4 +1,4 @@ -/* $OpenBSD: uipc_usrreq.c,v 1.165 2022/06/06 14:45:41 claudio Exp $ */ +/* $OpenBSD: uipc_usrreq.c,v 1.166 2022/07/01 09:56:17 mvs Exp $ */ /* $NetBSD: uipc_usrreq.c,v 1.18 1996/02/09 19:00:50 christos Exp $ */ /* @@ -55,6 +55,7 @@ #include <sys/mutex.h> #include <sys/sysctl.h> #include <sys/lock.h> +#include <sys/refcnt.h> #include "kcov.h" #if NKCOV > 0 @@ -66,9 +67,10 @@ * I immutable after creation * D unp_df_lock * G unp_gc_lock - * U unp_lock + * M unp_ino_mtx * R unp_rights_mtx * a atomic + * s socket lock */ struct rwlock unp_lock = RWLOCK_INITIALIZER("unplock"); @@ -76,6 +78,7 @@ struct rwlock unp_df_lock = RWLOCK_INITIALIZER("unpdflk"); struct rwlock unp_gc_lock = RWLOCK_INITIALIZER("unpgclk"); struct mutex unp_rights_mtx = MUTEX_INITIALIZER(IPL_SOFTNET); +struct mutex unp_ino_mtx = MUTEX_INITIALIZER(IPL_SOFTNET); /* * Stack of sets of files that were passed over a socket but were @@ -94,6 +97,9 @@ void unp_remove_gcrefs(struct fdpass *, int); void unp_restore_gcrefs(struct fdpass *, int); void unp_scan(struct mbuf *, void (*)(struct fdpass *, int)); int unp_nam2sun(struct mbuf *, struct sockaddr_un **, size_t *); +static inline void unp_ref(struct unpcb *); +static inline void unp_rele(struct unpcb *); +struct socket *unp_solock_peer(struct socket *); struct pool unpcb_pool; struct task unp_gc_task = TASK_INITIALIZER(unp_gc, NULL); @@ -127,6 +133,53 @@ unp_init(void) IPL_SOFTNET, 0, "unpcb", NULL); } +static inline void +unp_ref(struct unpcb *unp) +{ + refcnt_take(&unp->unp_refcnt); +} + +static inline void +unp_rele(struct unpcb *unp) +{ + refcnt_rele_wake(&unp->unp_refcnt); +} + +struct socket * +unp_solock_peer(struct socket *so) +{ + struct unpcb *unp, *unp2; + struct socket *so2; + + unp = so->so_pcb; + +again: + if ((unp2 = unp->unp_conn) == NULL) + return NULL; + + so2 = unp2->unp_socket; + + if (so < so2) + solock(so2); + else if (so > so2){ + unp_ref(unp2); + sounlock(so); + solock(so2); + solock(so); + + /* Datagram socket could be reconnected due to re-lock. */ + if (unp->unp_conn != unp2) { + sounlock(so2); + unp_rele(unp2); + goto again; + } + + unp_rele(unp2); + } + + return so2; +} + void uipc_setaddr(const struct unpcb *unp, struct mbuf *nam) { @@ -201,7 +254,10 @@ uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam, * if it was bound and we are still connected * (our peer may have closed already!). */ + so2 = unp_solock_peer(so); uipc_setaddr(unp->unp_conn, nam); + if (so2 != NULL && so2 != so) + sounlock(so2); break; case PRU_SHUTDOWN: @@ -218,9 +274,8 @@ uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam, case SOCK_STREAM: case SOCK_SEQPACKET: - if (unp->unp_conn == NULL) + if ((so2 = unp_solock_peer(so)) == NULL) break; - so2 = unp->unp_conn->unp_socket; /* * Adjust backpressure on sender * and wakeup any waiting to write. @@ -228,6 +283,7 @@ uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam, so2->so_snd.sb_mbcnt = so->so_rcv.sb_mbcnt; so2->so_snd.sb_cc = so->so_rcv.sb_cc; sowwakeup(so2); + sounlock(so2); break; default: @@ -256,13 +312,16 @@ uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam, error = unp_connect(so, nam, p); if (error) break; - } else { - if (unp->unp_conn == NULL) { + } + + if ((so2 = unp_solock_peer(so)) == NULL) { + if (nam != NULL) + error = ECONNREFUSED; + else error = ENOTCONN; - break; - } + break; } - so2 = unp->unp_conn->unp_socket; + if (unp->unp_addr) from = mtod(unp->unp_addr, struct sockaddr *); else @@ -273,6 +332,10 @@ uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam, control = NULL; } else error = ENOBUFS; + + if (so2 != so) + sounlock(so2); + if (nam) unp_disconnect(unp); break; @@ -284,11 +347,11 @@ uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam, error = EPIPE; break; } - if (unp->unp_conn == NULL) { + if ((so2 = unp_solock_peer(so)) == NULL) { error = ENOTCONN; break; } - so2 = unp->unp_conn->unp_socket; + /* * Send to paired receive port, and then raise * send buffer counts to maintain backpressure. @@ -310,6 +373,8 @@ uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam, so->so_snd.sb_cc = so2->so_rcv.sb_cc; if (so2->so_rcv.sb_cc > 0) sorwakeup(so2); + + sounlock(so2); m = NULL; break; @@ -323,12 +388,7 @@ uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam, case PRU_ABORT: unp_detach(unp); - /* - * As long as `unp_lock' is taken before entering - * uipc_usrreq() releasing it here would lead to a - * double unlock. - */ - sofree(so, 1); + sofree(so, 0); break; case PRU_SENSE: { @@ -336,8 +396,10 @@ uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam, sb->st_blksize = so->so_snd.sb_hiwat; sb->st_dev = NODEV; + mtx_enter(&unp_ino_mtx); if (unp->unp_ino == 0) unp->unp_ino = unp_ino++; + mtx_leave(&unp_ino_mtx); sb->st_atim.tv_sec = sb->st_mtim.tv_sec = sb->st_ctim.tv_sec = unp->unp_ctime.tv_sec; @@ -358,7 +420,10 @@ uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam, break; case PRU_PEERADDR: + so2 = unp_solock_peer(so); uipc_setaddr(unp->unp_conn, nam); + if (so2 != NULL && so2 != so) + sounlock(so2); break; case PRU_SLOWTIMO: @@ -410,8 +475,6 @@ uipc_attach(struct socket *so, int proto) struct unpcb *unp; int error; - rw_assert_wrlock(&unp_lock); - if (so->so_pcb) return EISCONN; if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { @@ -438,6 +501,7 @@ uipc_attach(struct socket *so, int proto) unp = pool_get(&unpcb_pool, PR_NOWAIT|PR_ZERO); if (unp == NULL) return (ENOBUFS); + refcnt_init(&unp->unp_refcnt); unp->unp_socket = so; so->so_pcb = unp; getnanotime(&unp->unp_ctime); @@ -445,12 +509,6 @@ uipc_attach(struct socket *so, int proto) /* * Enforce `unp_gc_lock' -> `solock()' lock order. */ - /* - * We also release the lock on listening socket and on our peer - * socket when called from unp_connect(). This is safe. The - * listening socket protected by vnode(9) lock. The peer socket - * has 'UNP_CONNECTING' flag set. - */ sounlock(so); rw_enter_write(&unp_gc_lock); LIST_INSERT_HEAD(&unp_head, unp, unp_link); @@ -512,14 +570,13 @@ unp_detach(struct unpcb *unp) { struct socket *so = unp->unp_socket; struct vnode *vp = unp->unp_vnode; - - rw_assert_wrlock(&unp_lock); + struct unpcb *unp2; unp->unp_vnode = NULL; /* * Enforce `unp_gc_lock' -> `solock()' lock order. - * Enforce `i_lock' -> `unp_lock' lock order. + * Enforce `i_lock' -> `solock()' lock order. */ sounlock(so); @@ -538,10 +595,47 @@ unp_detach(struct unpcb *unp) solock(so); - if (unp->unp_conn) + if (unp->unp_conn != NULL) { + /* + * Datagram socket could be connected to itself. + * Such socket will be disconnected here. + */ unp_disconnect(unp); - while (!SLIST_EMPTY(&unp->unp_refs)) - unp_drop(SLIST_FIRST(&unp->unp_refs), ECONNRESET); + } + + while ((unp2 = SLIST_FIRST(&unp->unp_refs)) != NULL) { + struct socket *so2 = unp2->unp_socket; + + if (so < so2) + solock(so2); + else { + unp_ref(unp2); + sounlock(so); + solock(so2); + solock(so); + + if (unp2->unp_conn != unp) { + /* `unp2' was disconnected due to re-lock. */ + sounlock(so2); + unp_rele(unp2); + continue; + } + + unp_rele(unp2); + } + + unp2->unp_conn = NULL; + SLIST_REMOVE(&unp->unp_refs, unp2, unpcb, unp_nextref); + so2->so_error = ECONNRESET; + so2->so_state &= ~SS_ISCONNECTED; + + sounlock(so2); + } + + sounlock(so); + refcnt_finalize(&unp->unp_refcnt, "unpfinal"); + solock(so); + soisdisconnected(so); so->so_pcb = NULL; m_freem(unp->unp_addr); @@ -681,24 +775,42 @@ unp_connect(struct socket *so, struct mbuf *nam, struct proc *p) } if ((error = VOP_ACCESS(vp, VWRITE, p->p_ucred, p)) != 0) goto put; - solock(so); so2 = vp->v_socket; if (so2 == NULL) { error = ECONNREFUSED; - goto put_locked; + goto put; } if (so->so_type != so2->so_type) { error = EPROTOTYPE; - goto put_locked; + goto put; } + if (so->so_proto->pr_flags & PR_CONNREQUIRED) { + solock(so2); + if ((so2->so_options & SO_ACCEPTCONN) == 0 || (so3 = sonewconn(so2, 0)) == NULL) { error = ECONNREFUSED; - goto put_locked; } + + sounlock(so2); + + if (error != 0) + goto put; + + /* + * Since `so2' is protected by vnode(9) lock, `so3' + * can't be PRU_ABORT'ed here. + */ + solock_pair(so, so3); + unp2 = sotounpcb(so2); unp3 = sotounpcb(so3); + + /* + * `unp_addr', `unp_connid' and 'UNP_FEIDSBIND' flag + * are immutable since we set them in unp_bind(). + */ if (unp2->unp_addr) unp3->unp_addr = m_copym(unp2->unp_addr, 0, M_COPYALL, M_NOWAIT); @@ -706,15 +818,29 @@ unp_connect(struct socket *so, struct mbuf *nam, struct proc *p) unp3->unp_connid.gid = p->p_ucred->cr_gid; unp3->unp_connid.pid = p->p_p->ps_pid; unp3->unp_flags |= UNP_FEIDS; - so2 = so3; + if (unp2->unp_flags & UNP_FEIDSBIND) { unp->unp_connid = unp2->unp_connid; unp->unp_flags |= UNP_FEIDS; } + + so2 = so3; + } else { + if (so2 != so) + solock_pair(so, so2); + else + solock(so); } + error = unp_connect2(so, so2); -put_locked: + sounlock(so); + + /* + * `so2' can't be PRU_ABORT'ed concurrently + */ + if (so2 != so) + sounlock(so2); put: vput(vp); unlock: @@ -738,7 +864,8 @@ unp_connect2(struct socket *so, struct socket *so2) struct unpcb *unp = sotounpcb(so); struct unpcb *unp2; - rw_assert_wrlock(&unp_lock); + soassertlocked(so); + soassertlocked(so2); if (so2->so_type != so->so_type) return (EPROTOTYPE); @@ -767,11 +894,15 @@ unp_connect2(struct socket *so, struct socket *so2) void unp_disconnect(struct unpcb *unp) { - struct unpcb *unp2 = unp->unp_conn; + struct socket *so2; + struct unpcb *unp2; - if (unp2 == NULL) + if ((so2 = unp_solock_peer(unp->unp_socket)) == NULL) return; + + unp2 = unp->unp_conn; unp->unp_conn = NULL; + switch (unp->unp_socket->so_type) { case SOCK_DGRAM: @@ -790,35 +921,31 @@ unp_disconnect(struct unpcb *unp) soisdisconnected(unp2->unp_socket); break; } + + if (so2 != unp->unp_socket) + sounlock(so2); } void unp_shutdown(struct unpcb *unp) { - struct socket *so; + struct socket *so2; switch (unp->unp_socket->so_type) { case SOCK_STREAM: case SOCK_SEQPACKET: - if (unp->unp_conn && (so = unp->unp_conn->unp_socket)) - socantrcvmore(so); + if ((so2 = unp_solock_peer(unp->unp_socket)) == NULL) + break; + + socantrcvmore(so2); + sounlock(so2); + break; default: break; } } -void -unp_drop(struct unpcb *unp, int errno) -{ - struct socket *so = unp->unp_socket; - - rw_assert_wrlock(&unp_lock); - - so->so_error = errno; - unp_disconnect(unp); -} - #ifdef notdef unp_drain(void) { |