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IABSD.fr/src/sys/kern/uipc_usrreq.c
deraadt
- sys/kern/uipc_usrreq.c
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/* $OpenBSD: uipc_usrreq.c,v 1.220 2025/06/12 20:37:58 deraadt Exp $ */ /* $NetBSD: uipc_usrreq.c,v 1.18 1996/02/09 19:00:50 christos Exp $ */ /* * Copyright (c) 1982, 1986, 1989, 1991, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94 */ #include <sys/param.h> #include <sys/systm.h> #include <sys/proc.h> #include <sys/filedesc.h> #include <sys/domain.h> #include <sys/protosw.h> #include <sys/queue.h> #include <sys/socket.h> #include <sys/socketvar.h> #include <sys/unpcb.h> #include <sys/un.h> #include <sys/namei.h> #include <sys/vnode.h> #include <sys/file.h> #include <sys/stat.h> #include <sys/mbuf.h> #include <sys/task.h> #include <sys/pledge.h> #include <sys/pool.h> #include <sys/rwlock.h> #include <sys/mutex.h> #include <sys/sysctl.h> #include <sys/lock.h> #include <sys/refcnt.h> #include "kcov.h" #if NKCOV > 0 #include <sys/kcov.h> #endif /* * Locks used to protect global data and struct members: * I immutable after creation * D unp_df_lock * G unp_gc_lock * M unp_ino_mtx * R unp_rights_mtx * a atomic * s socket lock */ 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 * not received and need to be closed. */ struct unp_deferral { SLIST_ENTRY(unp_deferral) ud_link; /* [D] */ int ud_n; /* [I] */ /* followed by ud_n struct fdpass */ struct fdpass ud_fp[]; /* [I] */ }; void uipc_setaddr(const struct unpcb *, struct mbuf *); void unp_discard(struct fdpass *, int); 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); /* * Unix communications domain. * * TODO: * RDM * rethink name space problems * need a proper out-of-band */ const struct sockaddr sun_noname = { sizeof(sun_noname), AF_UNIX }; /* [G] list of all UNIX domain sockets, for unp_gc() */ LIST_HEAD(unp_head, unpcb) unp_head = LIST_HEAD_INITIALIZER(unp_head); /* [D] list of sets of files that were sent over sockets that are now closed */ SLIST_HEAD(,unp_deferral) unp_deferred = SLIST_HEAD_INITIALIZER(unp_deferred); ino_t unp_ino; /* [U] prototype for fake inode numbers */ int unp_rights; /* [R] file descriptors in flight */ int unp_defer; /* [G] number of deferred fp to close by the GC task */ int unp_gcing; /* [G] GC task currently running */ const struct pr_usrreqs uipc_usrreqs = { .pru_attach = uipc_attach, .pru_detach = uipc_detach, .pru_bind = uipc_bind, .pru_listen = uipc_listen, .pru_connect = uipc_connect, .pru_accept = uipc_accept, .pru_disconnect = uipc_disconnect, .pru_shutdown = uipc_shutdown, .pru_rcvd = uipc_rcvd, .pru_send = uipc_send, .pru_abort = uipc_abort, .pru_sense = uipc_sense, .pru_sockaddr = uipc_sockaddr, .pru_peeraddr = uipc_peeraddr, .pru_connect2 = uipc_connect2, }; const struct pr_usrreqs uipc_dgram_usrreqs = { .pru_attach = uipc_attach, .pru_detach = uipc_detach, .pru_bind = uipc_bind, .pru_listen = uipc_listen, .pru_connect = uipc_connect, .pru_disconnect = uipc_disconnect, .pru_shutdown = uipc_dgram_shutdown, .pru_send = uipc_dgram_send, .pru_sense = uipc_sense, .pru_sockaddr = uipc_sockaddr, .pru_peeraddr = uipc_peeraddr, .pru_connect2 = uipc_connect2, }; void unp_init(void) { pool_init(&unpcb_pool, sizeof(struct unpcb), 0, 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) { if (unp != NULL && unp->unp_addr != NULL) { nam->m_len = unp->unp_addr->m_len; memcpy(mtod(nam, caddr_t), mtod(unp->unp_addr, caddr_t), nam->m_len); } else { nam->m_len = sizeof(sun_noname); memcpy(mtod(nam, struct sockaddr *), &sun_noname, nam->m_len); } } /* * Both send and receive buffers are allocated PIPSIZ bytes of buffering * for stream sockets, although the total for sender and receiver is * actually only PIPSIZ. * Datagram sockets really use the sendspace as the maximum datagram size, * and don't really want to reserve the sendspace. Their recvspace should * be large enough for at least one max-size datagram plus address. */ #define PIPSIZ 32768 u_int unpst_sendspace = PIPSIZ; /* [a] */ u_int unpst_recvspace = PIPSIZ; /* [a] */ u_int unpsq_sendspace = PIPSIZ; /* [a] */ u_int unpsq_recvspace = PIPSIZ; /* [a] */ u_int unpdg_sendspace = 8192; /* [a] really max datagram size */ u_int unpdg_recvspace = PIPSIZ; /* [a] */ #ifndef SMALL_KERNEL const struct sysctl_bounded_args unpstctl_vars[] = { { UNPCTL_RECVSPACE, &unpst_recvspace, 0, SB_MAX }, { UNPCTL_SENDSPACE, &unpst_sendspace, 0, SB_MAX }, }; const struct sysctl_bounded_args unpsqctl_vars[] = { { UNPCTL_RECVSPACE, &unpsq_recvspace, 0, SB_MAX }, { UNPCTL_SENDSPACE, &unpsq_sendspace, 0, SB_MAX }, }; const struct sysctl_bounded_args unpdgctl_vars[] = { { UNPCTL_RECVSPACE, &unpdg_recvspace, 0, SB_MAX }, { UNPCTL_SENDSPACE, &unpdg_sendspace, 0, SB_MAX }, }; #endif /* SMALL_KERNEL */ int uipc_attach(struct socket *so, int proto, int wait) { struct unpcb *unp; int error; if (so->so_pcb) return EISCONN; if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { switch (so->so_type) { case SOCK_STREAM: error = soreserve(so, atomic_load_int(&unpst_sendspace), atomic_load_int(&unpst_recvspace)); break; case SOCK_SEQPACKET: error = soreserve(so, atomic_load_int(&unpsq_sendspace), atomic_load_int(&unpsq_recvspace)); break; case SOCK_DGRAM: error = soreserve(so, atomic_load_int(&unpdg_sendspace), atomic_load_int(&unpdg_recvspace)); break; default: panic("unp_attach"); } if (error) return (error); } unp = pool_get(&unpcb_pool, (wait == M_WAIT ? PR_WAITOK : 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); rw_enter_write(&unp_gc_lock); LIST_INSERT_HEAD(&unp_head, unp, unp_link); rw_exit_write(&unp_gc_lock); return (0); } int uipc_detach(struct socket *so) { struct unpcb *unp = sotounpcb(so); if (unp == NULL) return (EINVAL); unp_detach(unp); return (0); } int uipc_bind(struct socket *so, struct mbuf *nam, struct proc *p) { struct unpcb *unp = sotounpcb(so); struct sockaddr_un *soun; struct mbuf *nam2; struct vnode *vp; struct vattr vattr; int error; struct nameidata nd; size_t pathlen; if (unp->unp_flags & (UNP_BINDING | UNP_CONNECTING)) return (EINVAL); if (unp->unp_vnode != NULL) return (EINVAL); if ((error = unp_nam2sun(nam, &soun, &pathlen))) return (error); unp->unp_flags |= UNP_BINDING; /* * Enforce `i_lock' -> `solock' because fifo subsystem * requires it. The socket can't be closed concurrently * because the file descriptor reference is still held. */ sounlock(unp->unp_socket); nam2 = m_getclr(M_WAITOK, MT_SONAME); nam2->m_len = sizeof(struct sockaddr_un); memcpy(mtod(nam2, struct sockaddr_un *), soun, offsetof(struct sockaddr_un, sun_path) + pathlen); /* No need to NUL terminate: m_getclr() returns zero'd mbufs. */ soun = mtod(nam2, struct sockaddr_un *); /* Fixup sun_len to keep it in sync with m_len. */ soun->sun_len = nam2->m_len; NDINIT(&nd, CREATE, NOFOLLOW | LOCKPARENT, UIO_SYSSPACE, soun->sun_path, p); nd.ni_pledge = PLEDGE_UNIX; nd.ni_unveil = UNVEIL_CREATE; KERNEL_LOCK(); /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ error = namei(&nd); if (error != 0) { m_freem(nam2); solock(unp->unp_socket); goto out; } vp = nd.ni_vp; if (vp != NULL) { VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd); if (nd.ni_dvp == vp) vrele(nd.ni_dvp); else vput(nd.ni_dvp); vrele(vp); m_freem(nam2); error = EADDRINUSE; solock(unp->unp_socket); goto out; } vattr_null(&vattr); vattr.va_type = VSOCK; vattr.va_mode = ACCESSPERMS &~ p->p_fd->fd_cmask; error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); vput(nd.ni_dvp); if (error) { m_freem(nam2); solock(unp->unp_socket); goto out; } solock(unp->unp_socket); unp->unp_addr = nam2; vp = nd.ni_vp; vp->v_socket = unp->unp_socket; unp->unp_vnode = vp; unp->unp_connid.uid = p->p_ucred->cr_uid; unp->unp_connid.gid = p->p_ucred->cr_gid; unp->unp_connid.pid = p->p_p->ps_pid; unp->unp_flags |= UNP_FEIDSBIND; VOP_UNLOCK(vp); out: KERNEL_UNLOCK(); unp->unp_flags &= ~UNP_BINDING; return (error); } int uipc_listen(struct socket *so) { struct unpcb *unp = sotounpcb(so); if (unp->unp_flags & (UNP_BINDING | UNP_CONNECTING)) return (EINVAL); if (unp->unp_vnode == NULL) return (EINVAL); return (0); } int uipc_connect(struct socket *so, struct mbuf *nam) { return unp_connect(so, nam, curproc); } int uipc_accept(struct socket *so, struct mbuf *nam) { struct socket *so2; struct unpcb *unp = sotounpcb(so); /* * Pass back name of connected socket, 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); return (0); } int uipc_disconnect(struct socket *so) { struct unpcb *unp = sotounpcb(so); unp_disconnect(unp); return (0); } int uipc_shutdown(struct socket *so) { struct unpcb *unp = sotounpcb(so); struct socket *so2; socantsendmore(so); if (unp->unp_conn != NULL) { so2 = unp->unp_conn->unp_socket; socantrcvmore(so2); } return (0); } int uipc_dgram_shutdown(struct socket *so) { socantsendmore(so); return (0); } void uipc_rcvd(struct socket *so) { struct unpcb *unp = sotounpcb(so); struct socket *so2; if (unp->unp_conn == NULL) return; so2 = unp->unp_conn->unp_socket; /* * Adjust backpressure on sender * and wakeup any waiting to write. */ mtx_enter(&so->so_rcv.sb_mtx); mtx_enter(&so2->so_snd.sb_mtx); so2->so_snd.sb_mbcnt = so->so_rcv.sb_mbcnt; so2->so_snd.sb_cc = so->so_rcv.sb_cc; mtx_leave(&so2->so_snd.sb_mtx); mtx_leave(&so->so_rcv.sb_mtx); sowwakeup(so2); } int uipc_send(struct socket *so, struct mbuf *m, struct mbuf *nam, struct mbuf *control) { struct unpcb *unp = sotounpcb(so); struct socket *so2; int error = 0, dowakeup = 0; if (control) { sounlock(so); error = unp_internalize(control, curproc); solock(so); if (error) goto out; } /* * We hold both solock() and `sb_mtx' mutex while modifying * SS_CANTSENDMORE flag. solock() is enough to check it. */ if (so->so_snd.sb_state & SS_CANTSENDMORE) { error = EPIPE; goto dispose; } if (unp->unp_conn == NULL) { error = ENOTCONN; goto dispose; } so2 = unp->unp_conn->unp_socket; /* * Send to paired receive port, and then raise * send buffer counts to maintain backpressure. * Wake up readers. */ /* * sbappend*() should be serialized together * with so_snd modification. */ mtx_enter(&so2->so_rcv.sb_mtx); mtx_enter(&so->so_snd.sb_mtx); if (control) { if (sbappendcontrol(&so2->so_rcv, m, control)) { control = NULL; } else { mtx_leave(&so->so_snd.sb_mtx); mtx_leave(&so2->so_rcv.sb_mtx); error = ENOBUFS; goto dispose; } } else if (so->so_type == SOCK_SEQPACKET) sbappendrecord(&so2->so_rcv, m); else sbappend(&so2->so_rcv, m); so->so_snd.sb_mbcnt = so2->so_rcv.sb_mbcnt; so->so_snd.sb_cc = so2->so_rcv.sb_cc; if (so2->so_rcv.sb_cc > 0) dowakeup = 1; mtx_leave(&so->so_snd.sb_mtx); mtx_leave(&so2->so_rcv.sb_mtx); if (dowakeup) sorwakeup(so2); m = NULL; dispose: /* we need to undo unp_internalize in case of errors */ if (control && error) unp_dispose(control); out: m_freem(control); m_freem(m); return (error); } int uipc_dgram_send(struct socket *so, struct mbuf *m, struct mbuf *nam, struct mbuf *control) { struct unpcb *unp = sotounpcb(so); struct socket *so2; const struct sockaddr *from; int error = 0, dowakeup = 0; if (control) { sounlock(so); error = unp_internalize(control, curproc); solock(so); if (error) goto out; } if (nam) { if (unp->unp_conn) { error = EISCONN; goto dispose; } error = unp_connect(so, nam, curproc); if (error) goto dispose; } if (unp->unp_conn == NULL) { if (nam != NULL) error = ECONNREFUSED; else error = ENOTCONN; goto dispose; } so2 = unp->unp_conn->unp_socket; if (unp->unp_addr) from = mtod(unp->unp_addr, struct sockaddr *); else from = &sun_noname; mtx_enter(&so2->so_rcv.sb_mtx); if (sbappendaddr(&so2->so_rcv, from, m, control)) { dowakeup = 1; m = NULL; control = NULL; } else error = ENOBUFS; mtx_leave(&so2->so_rcv.sb_mtx); if (dowakeup) sorwakeup(so2); if (nam) unp_disconnect(unp); dispose: /* we need to undo unp_internalize in case of errors */ if (control && error) unp_dispose(control); out: m_freem(control); m_freem(m); return (error); } void uipc_abort(struct socket *so) { struct unpcb *unp = sotounpcb(so); unp_detach(unp); sofree(so, 1); } int uipc_sense(struct socket *so, struct stat *sb) { struct unpcb *unp = sotounpcb(so); 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; sb->st_atim.tv_nsec = sb->st_mtim.tv_nsec = sb->st_ctim.tv_nsec = unp->unp_ctime.tv_nsec; sb->st_ino = unp->unp_ino; return (0); } int uipc_sockaddr(struct socket *so, struct mbuf *nam) { struct unpcb *unp = sotounpcb(so); uipc_setaddr(unp, nam); return (0); } int uipc_peeraddr(struct socket *so, struct mbuf *nam) { struct unpcb *unp = sotounpcb(so); struct socket *so2; so2 = unp_solock_peer(so); uipc_setaddr(unp->unp_conn, nam); if (so2 != NULL && so2 != so) sounlock(so2); return (0); } int uipc_connect2(struct socket *so, struct socket *so2) { struct unpcb *unp = sotounpcb(so), *unp2; int error; if ((error = unp_connect2(so, so2))) return (error); unp->unp_connid.uid = curproc->p_ucred->cr_uid; unp->unp_connid.gid = curproc->p_ucred->cr_gid; unp->unp_connid.pid = curproc->p_p->ps_pid; unp->unp_flags |= UNP_FEIDS; unp2 = sotounpcb(so2); unp2->unp_connid.uid = curproc->p_ucred->cr_uid; unp2->unp_connid.gid = curproc->p_ucred->cr_gid; unp2->unp_connid.pid = curproc->p_p->ps_pid; unp2->unp_flags |= UNP_FEIDS; return (0); } #ifndef SMALL_KERNEL int uipc_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp, size_t newlen) { int *valp = &unp_defer; /* All sysctl names at this level are terminal. */ switch (name[0]) { case SOCK_STREAM: if (namelen != 2) return (ENOTDIR); return sysctl_bounded_arr(unpstctl_vars, nitems(unpstctl_vars), name + 1, namelen - 1, oldp, oldlenp, newp, newlen); case SOCK_SEQPACKET: if (namelen != 2) return (ENOTDIR); return sysctl_bounded_arr(unpsqctl_vars, nitems(unpsqctl_vars), name + 1, namelen - 1, oldp, oldlenp, newp, newlen); case SOCK_DGRAM: if (namelen != 2) return (ENOTDIR); return sysctl_bounded_arr(unpdgctl_vars, nitems(unpdgctl_vars), name + 1, namelen - 1, oldp, oldlenp, newp, newlen); case NET_UNIX_INFLIGHT: valp = &unp_rights; /* FALLTHROUGH */ case NET_UNIX_DEFERRED: if (namelen != 1) return (ENOTDIR); return sysctl_rdint(oldp, oldlenp, newp, *valp); default: return (ENOPROTOOPT); } } #endif /* SMALL_KERNEL */ void unp_detach(struct unpcb *unp) { struct socket *so = unp->unp_socket; struct vnode *vp = unp->unp_vnode; struct unpcb *unp2; unp->unp_vnode = NULL; rw_enter_write(&unp_gc_lock); LIST_REMOVE(unp, unp_link); rw_exit_write(&unp_gc_lock); if (vp != NULL) { /* Enforce `i_lock' -> solock() lock order. */ sounlock(so); VOP_LOCK(vp, LK_EXCLUSIVE); vp->v_socket = NULL; KERNEL_LOCK(); vput(vp); KERNEL_UNLOCK(); solock(so); } if (unp->unp_conn != NULL) { /* * Datagram socket could be connected to itself. * Such socket will be disconnected here. */ unp_disconnect(unp); } 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); pool_put(&unpcb_pool, unp); if (unp_rights) task_add(systqmp, &unp_gc_task); } int unp_connect(struct socket *so, struct mbuf *nam, struct proc *p) { struct sockaddr_un *soun; struct vnode *vp; struct socket *so2, *so3; struct unpcb *unp, *unp2, *unp3; struct nameidata nd; int error; unp = sotounpcb(so); if (unp->unp_flags & (UNP_BINDING | UNP_CONNECTING)) return (EISCONN); if ((error = unp_nam2sun(nam, &soun, NULL))) return (error); NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, soun->sun_path, p); nd.ni_pledge = PLEDGE_UNIX; nd.ni_unveil = UNVEIL_WRITE; unp->unp_flags |= UNP_CONNECTING; /* * Enforce `i_lock' -> `solock' because fifo subsystem * requires it. The socket can't be closed concurrently * because the file descriptor reference is still held. */ sounlock(so); KERNEL_LOCK(); error = namei(&nd); if (error != 0) goto unlock; vp = nd.ni_vp; if (vp->v_type != VSOCK) { error = ENOTSOCK; goto put; } if ((error = VOP_ACCESS(vp, VWRITE, p->p_ucred, p)) != 0) goto put; so2 = vp->v_socket; if (so2 == NULL) { error = ECONNREFUSED; goto put; } if (so->so_type != so2->so_type) { error = EPROTOTYPE; goto put; } if (so->so_proto->pr_flags & PR_CONNREQUIRED) { solock(so2); if ((so2->so_options & SO_ACCEPTCONN) == 0 || (so3 = sonewconn(so2, 0, M_WAIT)) == NULL) { sounlock(so2); error = ECONNREFUSED; goto put; } /* * Since `so2' is protected by vnode(9) lock, `so3' * can't be PRU_ABORT'ed here. */ sounlock(so2); sounlock(so3); 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 uipc_bind(). */ if (unp2->unp_addr) unp3->unp_addr = m_copym(unp2->unp_addr, 0, M_COPYALL, M_NOWAIT); unp3->unp_connid.uid = p->p_ucred->cr_uid; unp3->unp_connid.gid = p->p_ucred->cr_gid; unp3->unp_connid.pid = p->p_p->ps_pid; unp3->unp_flags |= UNP_FEIDS; if (unp2->unp_flags & UNP_FEIDSBIND) { unp->unp_connid = unp2->unp_connid; unp->unp_flags |= UNP_FEIDS; } so2 = so3; } else solock_pair(so, so2); error = unp_connect2(so, so2); /* * `so2' can't be PRU_ABORT'ed concurrently */ sounlock_pair(so, so2); put: vput(vp); unlock: KERNEL_UNLOCK(); solock(so); unp->unp_flags &= ~UNP_CONNECTING; /* * The peer socket could be closed by concurrent thread * when `so' and `vp' are unlocked. */ if (error == 0 && unp->unp_conn == NULL) error = ECONNREFUSED; return (error); } int unp_connect2(struct socket *so, struct socket *so2) { struct unpcb *unp = sotounpcb(so); struct unpcb *unp2; soassertlocked(so); soassertlocked(so2); if (so2->so_type != so->so_type) return (EPROTOTYPE); unp2 = sotounpcb(so2); unp->unp_conn = unp2; switch (so->so_type) { case SOCK_DGRAM: SLIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_nextref); soisconnected(so); break; case SOCK_STREAM: case SOCK_SEQPACKET: unp2->unp_conn = unp; soisconnected(so); soisconnected(so2); break; default: panic("unp_connect2"); } return (0); } void unp_disconnect(struct unpcb *unp) { struct socket *so2; struct unpcb *unp2; 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: SLIST_REMOVE(&unp2->unp_refs, unp, unpcb, unp_nextref); unp->unp_socket->so_state &= ~SS_ISCONNECTED; break; case SOCK_STREAM: case SOCK_SEQPACKET: unp->unp_socket->so_snd.sb_mbcnt = 0; unp->unp_socket->so_snd.sb_cc = 0; soisdisconnected(unp->unp_socket); unp2->unp_conn = NULL; unp2->unp_socket->so_snd.sb_mbcnt = 0; unp2->unp_socket->so_snd.sb_cc = 0; soisdisconnected(unp2->unp_socket); break; } if (so2 != unp->unp_socket) sounlock(so2); } static struct unpcb * fptounp(struct file *fp) { struct socket *so; if (fp->f_type != DTYPE_SOCKET) return (NULL); if ((so = fp->f_data) == NULL) return (NULL); if (so->so_proto->pr_domain != &unixdomain) return (NULL); return (sotounpcb(so)); } int unp_externalize(struct mbuf *rights, socklen_t controllen, int flags) { struct proc *p = curproc; /* XXX */ struct cmsghdr *cm = mtod(rights, struct cmsghdr *); struct filedesc *fdp = p->p_fd; int i, *fds = NULL; struct fdpass *rp; struct file *fp; int nfds, error = 0; /* * This code only works because SCM_RIGHTS is the only supported * control message type on unix sockets. Enforce this here. */ if (cm->cmsg_type != SCM_RIGHTS || cm->cmsg_level != SOL_SOCKET) return EINVAL; nfds = (cm->cmsg_len - CMSG_ALIGN(sizeof(*cm))) / sizeof(struct fdpass); if (controllen < CMSG_ALIGN(sizeof(struct cmsghdr))) controllen = 0; else controllen -= CMSG_ALIGN(sizeof(struct cmsghdr)); if (nfds > controllen / sizeof(int)) { error = EMSGSIZE; goto out; } /* Make sure the recipient should be able to see the descriptors.. */ rp = (struct fdpass *)CMSG_DATA(cm); /* fdp->fd_rdir requires KERNEL_LOCK() */ KERNEL_LOCK(); for (i = 0; i < nfds; i++) { fp = rp->fp; rp++; error = pledge_recvfd(p, fp); if (error) break; /* * No to block devices. If passing a directory, * make sure that it is underneath the root. */ if (fdp->fd_rdir != NULL && fp->f_type == DTYPE_VNODE) { struct vnode *vp = (struct vnode *)fp->f_data; if (vp->v_type == VBLK || (vp->v_type == VDIR && !vn_isunder(vp, fdp->fd_rdir, p))) { error = EPERM; break; } } } KERNEL_UNLOCK(); if (error) goto out; fds = mallocarray(nfds, sizeof(int), M_TEMP, M_WAITOK); fdplock(fdp); restart: /* * First loop -- allocate file descriptor table slots for the * new descriptors. */ rp = ((struct fdpass *)CMSG_DATA(cm)); for (i = 0; i < nfds; i++) { if ((error = fdalloc(p, 0, &fds[i])) != 0) { /* * Back out what we've done so far. */ for (--i; i >= 0; i--) fdremove(fdp, fds[i]); if (error == ENOSPC) { fdexpand(p); goto restart; } fdpunlock(fdp); /* * This is the error that has historically * been returned, and some callers may * expect it. */ error = EMSGSIZE; goto out; } /* * Make the slot reference the descriptor so that * fdalloc() works properly.. We finalize it all * in the loop below. */ mtx_enter(&fdp->fd_fplock); KASSERT(fdp->fd_ofiles[fds[i]] == NULL); fdp->fd_ofiles[fds[i]] = rp->fp; mtx_leave(&fdp->fd_fplock); fdp->fd_ofileflags[fds[i]] = (rp->flags & UF_PLEDGED); if (flags & MSG_CMSG_CLOEXEC) fdp->fd_ofileflags[fds[i]] |= UF_EXCLOSE; rp++; } /* * Keep `fdp' locked to prevent concurrent close() of just * inserted descriptors. Such descriptors could have the only * `f_count' reference which is now shared between control * message and `fdp'. */ /* * Now that adding them has succeeded, update all of the * descriptor passing state. */ rp = (struct fdpass *)CMSG_DATA(cm); for (i = 0; i < nfds; i++) { struct unpcb *unp; fp = rp->fp; rp++; if ((unp = fptounp(fp)) != NULL) { rw_enter_write(&unp_gc_lock); unp->unp_msgcount--; rw_exit_write(&unp_gc_lock); } } fdpunlock(fdp); mtx_enter(&unp_rights_mtx); unp_rights -= nfds; mtx_leave(&unp_rights_mtx); /* * Copy temporary array to message and adjust length, in case of * transition from large struct file pointers to ints. */ memcpy(CMSG_DATA(cm), fds, nfds * sizeof(int)); cm->cmsg_len = CMSG_LEN(nfds * sizeof(int)); rights->m_len = CMSG_LEN(nfds * sizeof(int)); out: if (fds != NULL) free(fds, M_TEMP, nfds * sizeof(int)); if (error) { if (nfds > 0) { /* * No lock required. We are the only `cm' holder. */ rp = ((struct fdpass *)CMSG_DATA(cm)); unp_discard(rp, nfds); } } return (error); } int unp_internalize(struct mbuf *control, struct proc *p) { struct filedesc *fdp = p->p_fd; struct cmsghdr *cm = mtod(control, struct cmsghdr *); struct fdpass *rp; struct file *fp; struct unpcb *unp; int i, error; int nfds, *ip, fd, neededspace; /* * Check for two potential msg_controllen values because * IETF stuck their nose in a place it does not belong. */ if (control->m_len < CMSG_LEN(0) || cm->cmsg_len < CMSG_LEN(0)) return (EINVAL); if (cm->cmsg_type != SCM_RIGHTS || cm->cmsg_level != SOL_SOCKET || !(cm->cmsg_len == control->m_len || control->m_len == CMSG_ALIGN(cm->cmsg_len))) return (EINVAL); nfds = (cm->cmsg_len - CMSG_ALIGN(sizeof(*cm))) / sizeof (int); mtx_enter(&unp_rights_mtx); if (unp_rights + nfds > maxfiles / 10) { mtx_leave(&unp_rights_mtx); return (EMFILE); } unp_rights += nfds; mtx_leave(&unp_rights_mtx); /* Make sure we have room for the struct file pointers */ morespace: neededspace = CMSG_SPACE(nfds * sizeof(struct fdpass)) - control->m_len; if (neededspace > m_trailingspace(control)) { char *tmp; /* if we already have a cluster, the message is just too big */ if (control->m_flags & M_EXT) { error = E2BIG; goto nospace; } /* copy cmsg data temporarily out of the mbuf */ tmp = malloc(control->m_len, M_TEMP, M_WAITOK); memcpy(tmp, mtod(control, caddr_t), control->m_len); /* allocate a cluster and try again */ MCLGET(control, M_WAIT); if ((control->m_flags & M_EXT) == 0) { free(tmp, M_TEMP, control->m_len); error = ENOBUFS; /* allocation failed */ goto nospace; } /* copy the data back into the cluster */ cm = mtod(control, struct cmsghdr *); memcpy(cm, tmp, control->m_len); free(tmp, M_TEMP, control->m_len); goto morespace; } /* adjust message & mbuf to note amount of space actually used. */ cm->cmsg_len = CMSG_LEN(nfds * sizeof(struct fdpass)); control->m_len = CMSG_SPACE(nfds * sizeof(struct fdpass)); ip = ((int *)CMSG_DATA(cm)) + nfds - 1; rp = ((struct fdpass *)CMSG_DATA(cm)) + nfds - 1; fdplock(fdp); for (i = 0; i < nfds; i++) { memcpy(&fd, ip, sizeof fd); ip--; if ((fp = fd_getfile(fdp, fd)) == NULL) { error = EBADF; goto fail; } if (fp->f_count >= FDUP_MAX_COUNT) { error = EDEADLK; goto fail; } error = pledge_sendfd(p, fp); if (error) goto fail; /* kqueue descriptors cannot be copied */ if (fp->f_type == DTYPE_KQUEUE) { error = EINVAL; goto fail; } #if NKCOV > 0 /* kcov descriptors cannot be copied */ if (fp->f_type == DTYPE_VNODE && kcov_vnode(fp->f_data)) { error = EINVAL; goto fail; } #endif rp->fp = fp; rp->flags = fdp->fd_ofileflags[fd] & UF_PLEDGED; rp--; if ((unp = fptounp(fp)) != NULL) { rw_enter_write(&unp_gc_lock); unp->unp_msgcount++; unp->unp_file = fp; rw_exit_write(&unp_gc_lock); } } fdpunlock(fdp); return (0); fail: fdpunlock(fdp); if (fp != NULL) FRELE(fp, p); /* Back out what we just did. */ for ( ; i > 0; i--) { rp++; fp = rp->fp; if ((unp = fptounp(fp)) != NULL) { rw_enter_write(&unp_gc_lock); unp->unp_msgcount--; rw_exit_write(&unp_gc_lock); } FRELE(fp, p); } nospace: mtx_enter(&unp_rights_mtx); unp_rights -= nfds; mtx_leave(&unp_rights_mtx); return (error); } void unp_gc(void *arg __unused) { struct unp_deferral *defer; struct file *fp; struct socket *so; struct unpcb *unp; int nunref, i; rw_enter_write(&unp_gc_lock); if (unp_gcing) goto unlock; unp_gcing = 1; rw_exit_write(&unp_gc_lock); rw_enter_write(&unp_df_lock); /* close any fds on the deferred list */ while ((defer = SLIST_FIRST(&unp_deferred)) != NULL) { SLIST_REMOVE_HEAD(&unp_deferred, ud_link); rw_exit_write(&unp_df_lock); for (i = 0; i < defer->ud_n; i++) { fp = defer->ud_fp[i].fp; if (fp == NULL) continue; if ((unp = fptounp(fp)) != NULL) { rw_enter_write(&unp_gc_lock); unp->unp_msgcount--; rw_exit_write(&unp_gc_lock); } mtx_enter(&unp_rights_mtx); unp_rights--; mtx_leave(&unp_rights_mtx); /* closef() expects a refcount of 2 */ FREF(fp); (void) closef(fp, NULL); } free(defer, M_TEMP, sizeof(*defer) + sizeof(struct fdpass) * defer->ud_n); rw_enter_write(&unp_df_lock); } rw_exit_write(&unp_df_lock); nunref = 0; rw_enter_write(&unp_gc_lock); /* * Determine sockets which may be prospectively dead. Such * sockets have their `unp_msgcount' equal to the `f_count'. * If `unp_msgcount' is 0, the socket has not been passed * and can't be unreferenced. */ LIST_FOREACH(unp, &unp_head, unp_link) { unp->unp_gcflags = 0; if (unp->unp_msgcount == 0) continue; if ((fp = unp->unp_file) == NULL) continue; if (fp->f_count == unp->unp_msgcount) { unp->unp_gcflags |= UNP_GCDEAD; unp->unp_gcrefs = unp->unp_msgcount; nunref++; } } /* * Scan all sockets previously marked as dead. Remove * the `unp_gcrefs' reference each socket holds on any * dead socket in its buffer. */ LIST_FOREACH(unp, &unp_head, unp_link) { if ((unp->unp_gcflags & UNP_GCDEAD) == 0) continue; so = unp->unp_socket; mtx_enter(&so->so_rcv.sb_mtx); unp_scan(so->so_rcv.sb_mb, unp_remove_gcrefs); mtx_leave(&so->so_rcv.sb_mtx); } /* * If the dead socket has `unp_gcrefs' reference counter * greater than 0, it can't be unreferenced. Mark it as * alive and increment the `unp_gcrefs' reference for each * dead socket within its buffer. Repeat this until we * have no new alive sockets found. */ do { unp_defer = 0; LIST_FOREACH(unp, &unp_head, unp_link) { if ((unp->unp_gcflags & UNP_GCDEAD) == 0) continue; if (unp->unp_gcrefs == 0) continue; unp->unp_gcflags &= ~UNP_GCDEAD; so = unp->unp_socket; mtx_enter(&so->so_rcv.sb_mtx); unp_scan(so->so_rcv.sb_mb, unp_restore_gcrefs); mtx_leave(&so->so_rcv.sb_mtx); KASSERT(nunref > 0); nunref--; } } while (unp_defer > 0); /* * If there are any unreferenced sockets, then for each dispose * of files in its receive buffer and then close it. */ if (nunref) { LIST_FOREACH(unp, &unp_head, unp_link) { if (unp->unp_gcflags & UNP_GCDEAD) { struct sockbuf *sb = &unp->unp_socket->so_rcv; struct mbuf *m; /* * This socket could still be connected * and if so it's `so_rcv' is still * accessible by concurrent PRU_SEND * thread. */ mtx_enter(&sb->sb_mtx); m = sb->sb_mb; memset(&sb->sb_startzero, 0, (caddr_t)&sb->sb_endzero - (caddr_t)&sb->sb_startzero); sb->sb_timeo_nsecs = INFSLP; mtx_leave(&sb->sb_mtx); unp_scan(m, unp_discard); m_purge(m); } } } unp_gcing = 0; unlock: rw_exit_write(&unp_gc_lock); } void unp_dispose(struct mbuf *m) { if (m) unp_scan(m, unp_discard); } void unp_scan(struct mbuf *m0, void (*op)(struct fdpass *, int)) { struct mbuf *m; struct fdpass *rp; struct cmsghdr *cm; int qfds; while (m0) { for (m = m0; m; m = m->m_next) { if (m->m_type == MT_CONTROL && m->m_len >= sizeof(*cm)) { cm = mtod(m, struct cmsghdr *); if (cm->cmsg_level != SOL_SOCKET || cm->cmsg_type != SCM_RIGHTS) continue; qfds = (cm->cmsg_len - CMSG_ALIGN(sizeof *cm)) / sizeof(struct fdpass); if (qfds > 0) { rp = (struct fdpass *)CMSG_DATA(cm); op(rp, qfds); } break; /* XXX, but saves time */ } } m0 = m0->m_nextpkt; } } void unp_discard(struct fdpass *rp, int nfds) { struct unp_deferral *defer; /* copy the file pointers to a deferral structure */ defer = malloc(sizeof(*defer) + sizeof(*rp) * nfds, M_TEMP, M_WAITOK); defer->ud_n = nfds; memcpy(&defer->ud_fp[0], rp, sizeof(*rp) * nfds); memset(rp, 0, sizeof(*rp) * nfds); rw_enter_write(&unp_df_lock); SLIST_INSERT_HEAD(&unp_deferred, defer, ud_link); rw_exit_write(&unp_df_lock); task_add(systqmp, &unp_gc_task); } void unp_remove_gcrefs(struct fdpass *rp, int nfds) { struct unpcb *unp; int i; rw_assert_wrlock(&unp_gc_lock); for (i = 0; i < nfds; i++) { if (rp[i].fp == NULL) continue; if ((unp = fptounp(rp[i].fp)) == NULL) continue; if (unp->unp_gcflags & UNP_GCDEAD) { KASSERT(unp->unp_gcrefs > 0); unp->unp_gcrefs--; } } } void unp_restore_gcrefs(struct fdpass *rp, int nfds) { struct unpcb *unp; int i; rw_assert_wrlock(&unp_gc_lock); for (i = 0; i < nfds; i++) { if (rp[i].fp == NULL) continue; if ((unp = fptounp(rp[i].fp)) == NULL) continue; if (unp->unp_gcflags & UNP_GCDEAD) { unp->unp_gcrefs++; unp_defer++; } } } int unp_nam2sun(struct mbuf *nam, struct sockaddr_un **sun, size_t *pathlen) { struct sockaddr *sa = mtod(nam, struct sockaddr *); size_t size, len; if (nam->m_len < offsetof(struct sockaddr, sa_data)) return EINVAL; if (sa->sa_family != AF_UNIX) return EAFNOSUPPORT; if (sa->sa_len != nam->m_len) return EINVAL; if (sa->sa_len > sizeof(struct sockaddr_un)) return EINVAL; *sun = (struct sockaddr_un *)sa; /* ensure that sun_path is NUL terminated and fits */ size = (*sun)->sun_len - offsetof(struct sockaddr_un, sun_path); len = strnlen((*sun)->sun_path, size); if (len == sizeof((*sun)->sun_path)) return EINVAL; if (len == size) { if (m_trailingspace(nam) == 0) return EINVAL; nam->m_len++; (*sun)->sun_len++; (*sun)->sun_path[len] = '\0'; } if (pathlen != NULL) *pathlen = len; return 0; }