/*- * Copyright (c) 1982, 1986, 1989, 1991, 1993 * The Regents of the University of California. * Copyright (c) 2004-2007 Robert N. M. Watson * 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. * 4. 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. * * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94 */ /* * UNIX Domain (Local) Sockets * * This is an implementation of UNIX (local) domain sockets. Each socket has * an associated struct unpcb (UNIX protocol control block). Stream sockets * may be connected to 0 or 1 other socket. Datagram sockets may be * connected to 0, 1, or many other sockets. Sockets may be created and * connected in pairs (socketpair(2)), or bound/connected to using the file * system name space. For most purposes, only the receive socket buffer is * used, as sending on one socket delivers directly to the receive socket * buffer of a second socket. * * The implementation is substantially complicated by the fact that * "ancillary data", such as file descriptors or credentials, may be passed * across UNIX domain sockets. The potential for passing UNIX domain sockets * over other UNIX domain sockets requires the implementation of a simple * garbage collector to find and tear down cycles of disconnected sockets. * * TODO: * SEQPACKET, RDM * rethink name space problems * need a proper out-of-band * lock pushdown */ #include __FBSDID("$FreeBSD$"); #include "opt_ddb.h" #include "opt_mac.h" #include #include #include #include /* XXX must be before */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DDB #include #endif #include #include static uma_zone_t unp_zone; static unp_gen_t unp_gencnt; static u_int unp_count; /* Count of local sockets. */ static ino_t unp_ino; /* Prototype for fake inode numbers. */ static int unp_rights; /* File descriptors in flight. */ static struct unp_head unp_shead; /* List of local stream sockets. */ static struct unp_head unp_dhead; /* List of local datagram sockets. */ static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; /* * Garbage collection of cyclic file descriptor/socket references occurs * asynchronously in a taskqueue context in order to avoid recursion and * reentrance in the UNIX domain socket, file descriptor, and socket layer * code. See unp_gc() for a full description. */ static struct task unp_gc_task; /* * 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. */ #ifndef PIPSIZ #define PIPSIZ 8192 #endif static u_long unpst_sendspace = PIPSIZ; static u_long unpst_recvspace = PIPSIZ; static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ static u_long unpdg_recvspace = 4*1024; SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain"); SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0, "SOCK_STREAM"); SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM"); SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, &unpst_sendspace, 0, ""); SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, &unpst_recvspace, 0, ""); SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, &unpdg_sendspace, 0, ""); SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, &unpdg_recvspace, 0, ""); SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, ""); /*- * Locking and synchronization: * * The global UNIX domain socket rwlock (unp_global_rwlock) protects all * global variables, including the linked lists tracking the set of allocated * UNIX domain sockets. The global rwlock also serves to prevent deadlock * when more than one PCB lock is acquired at a time (i.e., during * connect()). Finally, the global rwlock protects uncounted references from * vnodes to sockets bound to those vnodes: to safely dereference the * v_socket pointer, the global rwlock must be held while a full reference is * acquired. * * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer, * allocated in pru_attach() and freed in pru_detach(). The validity of that * pointer is an invariant, so no lock is required to dereference the so_pcb * pointer if a valid socket reference is held by the caller. In practice, * this is always true during operations performed on a socket. Each unpcb * has a back-pointer to its socket, unp_socket, which will be stable under * the same circumstances. * * This pointer may only be safely dereferenced as long as a valid reference * to the unpcb is held. Typically, this reference will be from the socket, * or from another unpcb when the referring unpcb's lock is held (in order * that the reference not be invalidated during use). For example, to follow * unp->unp_conn->unp_socket, you need unlock the lock on unp, not unp_conn, * as unp_socket remains valid as long as the reference to unp_conn is valid. * * Fields of unpcbss are locked using a per-unpcb lock, unp_mtx. Individual * atomic reads without the lock may be performed "lockless", but more * complex reads and read-modify-writes require the mutex to be held. No * lock order is defined between unpcb locks -- multiple unpcb locks may be * acquired at the same time only when holding the global UNIX domain socket * rwlock exclusively, which prevents deadlocks. * * Blocking with UNIX domain sockets is a tricky issue: unlike most network * protocols, bind() is a non-atomic operation, and connect() requires * potential sleeping in the protocol, due to potentially waiting on local or * distributed file systems. We try to separate "lookup" operations, which * may sleep, and the IPC operations themselves, which typically can occur * with relative atomicity as locks can be held over the entire operation. * * Another tricky issue is simultaneous multi-threaded or multi-process * access to a single UNIX domain socket. These are handled by the flags * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or * binding, both of which involve dropping UNIX domain socket locks in order * to perform namei() and other file system operations. */ static struct rwlock unp_global_rwlock; #define UNP_GLOBAL_LOCK_INIT() rw_init(&unp_global_rwlock, \ "unp_global_rwlock") #define UNP_GLOBAL_LOCK_ASSERT() rw_assert(&unp_global_rwlock, \ RA_LOCKED) #define UNP_GLOBAL_UNLOCK_ASSERT() rw_assert(&unp_global_rwlock, \ RA_UNLOCKED) #define UNP_GLOBAL_WLOCK() rw_wlock(&unp_global_rwlock) #define UNP_GLOBAL_WUNLOCK() rw_wunlock(&unp_global_rwlock) #define UNP_GLOBAL_WLOCK_ASSERT() rw_assert(&unp_global_rwlock, \ RA_WLOCKED) #define UNP_GLOBAL_WOWNED() rw_wowned(&unp_global_rwlock) #define UNP_GLOBAL_RLOCK() rw_rlock(&unp_global_rwlock) #define UNP_GLOBAL_RUNLOCK() rw_runlock(&unp_global_rwlock) #define UNP_GLOBAL_RLOCK_ASSERT() rw_assert(&unp_global_rwlock, \ RA_RLOCKED) #define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \ "unp_mtx", "unp_mtx", \ MTX_DUPOK|MTX_DEF|MTX_RECURSE) #define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx) #define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx) #define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx) #define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED) static int unp_connect(struct socket *, struct sockaddr *, struct thread *); static int unp_connect2(struct socket *so, struct socket *so2, int); static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2); static void unp_shutdown(struct unpcb *); static void unp_drop(struct unpcb *, int); static void unp_gc(__unused void *, int); static void unp_scan(struct mbuf *, void (*)(struct file *)); static void unp_discard(struct file *); static void unp_freerights(struct file **, int); static int unp_internalize(struct mbuf **, struct thread *); static void unp_internalize_fp(struct file *); static void unp_externalize_fp(struct file *); static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *); /* * Definitions of protocols supported in the LOCAL domain. */ static struct domain localdomain; static struct protosw localsw[] = { { .pr_type = SOCK_STREAM, .pr_domain = &localdomain, .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS, .pr_ctloutput = &uipc_ctloutput, .pr_usrreqs = &uipc_usrreqs }, { .pr_type = SOCK_DGRAM, .pr_domain = &localdomain, .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS, .pr_usrreqs = &uipc_usrreqs }, }; static struct domain localdomain = { .dom_family = AF_LOCAL, .dom_name = "local", .dom_init = unp_init, .dom_externalize = unp_externalize, .dom_dispose = unp_dispose, .dom_protosw = localsw, .dom_protoswNPROTOSW = &localsw[sizeof(localsw)/sizeof(localsw[0])] }; DOMAIN_SET(local); static void uipc_abort(struct socket *so) { struct unpcb *unp, *unp2; unp = sotounpcb(so); KASSERT(unp != NULL, ("uipc_abort: unp == NULL")); UNP_GLOBAL_WLOCK(); UNP_PCB_LOCK(unp); unp2 = unp->unp_conn; if (unp2 != NULL) { UNP_PCB_LOCK(unp2); unp_drop(unp2, ECONNABORTED); UNP_PCB_UNLOCK(unp2); } UNP_PCB_UNLOCK(unp); UNP_GLOBAL_WUNLOCK(); } static int uipc_accept(struct socket *so, struct sockaddr **nam) { struct unpcb *unp, *unp2; const struct sockaddr *sa; /* * Pass back name of connected socket, if it was bound and we are * still connected (our peer may have closed already!). */ unp = sotounpcb(so); KASSERT(unp != NULL, ("uipc_accept: unp == NULL")); *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); UNP_GLOBAL_RLOCK(); unp2 = unp->unp_conn; if (unp2 != NULL && unp2->unp_addr != NULL) { UNP_PCB_LOCK(unp2); sa = (struct sockaddr *) unp2->unp_addr; bcopy(sa, *nam, sa->sa_len); UNP_PCB_UNLOCK(unp2); } else { sa = &sun_noname; bcopy(sa, *nam, sa->sa_len); } UNP_GLOBAL_RUNLOCK(); return (0); } static int uipc_attach(struct socket *so, int proto, struct thread *td) { u_long sendspace, recvspace; struct unpcb *unp; int error, locked; KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL")); if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { switch (so->so_type) { case SOCK_STREAM: sendspace = unpst_sendspace; recvspace = unpst_recvspace; break; case SOCK_DGRAM: sendspace = unpdg_sendspace; recvspace = unpdg_recvspace; break; default: panic("uipc_attach"); } error = soreserve(so, sendspace, recvspace); if (error) return (error); } unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO); if (unp == NULL) return (ENOBUFS); LIST_INIT(&unp->unp_refs); UNP_PCB_LOCK_INIT(unp); unp->unp_socket = so; so->so_pcb = unp; unp->unp_refcount = 1; /* * uipc_attach() may be called indirectly from within the UNIX domain * socket code via sonewconn() in unp_connect(). Since rwlocks can * not be recursed, we do the closest thing. */ locked = 0; if (!UNP_GLOBAL_WOWNED()) { UNP_GLOBAL_WLOCK(); locked = 1; } unp->unp_gencnt = ++unp_gencnt; unp_count++; LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead : &unp_shead, unp, unp_link); if (locked) UNP_GLOBAL_WUNLOCK(); return (0); } static int uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) { struct sockaddr_un *soun = (struct sockaddr_un *)nam; struct vattr vattr; int error, namelen, vfslocked; struct nameidata nd; struct unpcb *unp; struct vnode *vp; struct mount *mp; char *buf; unp = sotounpcb(so); KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); if (namelen <= 0) return (EINVAL); /* * We don't allow simultaneous bind() calls on a single UNIX domain * socket, so flag in-progress operations, and return an error if an * operation is already in progress. * * Historically, we have not allowed a socket to be rebound, so this * also returns an error. Not allowing re-binding simplifies the * implementation and avoids a great many possible failure modes. */ UNP_PCB_LOCK(unp); if (unp->unp_vnode != NULL) { UNP_PCB_UNLOCK(unp); return (EINVAL); } if (unp->unp_flags & UNP_BINDING) { UNP_PCB_UNLOCK(unp); return (EALREADY); } unp->unp_flags |= UNP_BINDING; UNP_PCB_UNLOCK(unp); buf = malloc(namelen + 1, M_TEMP, M_WAITOK); strlcpy(buf, soun->sun_path, namelen + 1); restart: vfslocked = 0; NDINIT(&nd, CREATE, MPSAFE | NOFOLLOW | LOCKPARENT | SAVENAME, UIO_SYSSPACE, buf, td); /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ error = namei(&nd); if (error) goto error; vp = nd.ni_vp; vfslocked = NDHASGIANT(&nd); if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { NDFREE(&nd, NDF_ONLY_PNBUF); if (nd.ni_dvp == vp) vrele(nd.ni_dvp); else vput(nd.ni_dvp); if (vp != NULL) { vrele(vp); error = EADDRINUSE; goto error; } error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); if (error) goto error; VFS_UNLOCK_GIANT(vfslocked); goto restart; } VATTR_NULL(&vattr); vattr.va_type = VSOCK; vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); #ifdef MAC error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, &vattr); #endif if (error == 0) { VOP_LEASE(nd.ni_dvp, td, td->td_ucred, LEASE_WRITE); error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); } NDFREE(&nd, NDF_ONLY_PNBUF); vput(nd.ni_dvp); if (error) { vn_finished_write(mp); goto error; } vp = nd.ni_vp; ASSERT_VOP_ELOCKED(vp, "uipc_bind"); soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); UNP_GLOBAL_WLOCK(); UNP_PCB_LOCK(unp); vp->v_socket = unp->unp_socket; unp->unp_vnode = vp; unp->unp_addr = soun; unp->unp_flags &= ~UNP_BINDING; UNP_PCB_UNLOCK(unp); UNP_GLOBAL_WUNLOCK(); VOP_UNLOCK(vp, 0, td); vn_finished_write(mp); VFS_UNLOCK_GIANT(vfslocked); free(buf, M_TEMP); return (0); error: VFS_UNLOCK_GIANT(vfslocked); UNP_PCB_LOCK(unp); unp->unp_flags &= ~UNP_BINDING; UNP_PCB_UNLOCK(unp); free(buf, M_TEMP); return (error); } static int uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) { int error; KASSERT(td == curthread, ("uipc_connect: td != curthread")); UNP_GLOBAL_WLOCK(); error = unp_connect(so, nam, td); UNP_GLOBAL_WUNLOCK(); return (error); } static void uipc_close(struct socket *so) { struct unpcb *unp, *unp2; unp = sotounpcb(so); KASSERT(unp != NULL, ("uipc_close: unp == NULL")); UNP_GLOBAL_WLOCK(); UNP_PCB_LOCK(unp); unp2 = unp->unp_conn; if (unp2 != NULL) { UNP_PCB_LOCK(unp2); unp_disconnect(unp, unp2); UNP_PCB_UNLOCK(unp2); } UNP_PCB_UNLOCK(unp); UNP_GLOBAL_WUNLOCK(); } int uipc_connect2(struct socket *so1, struct socket *so2) { struct unpcb *unp, *unp2; int error; UNP_GLOBAL_WLOCK(); unp = so1->so_pcb; KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); UNP_PCB_LOCK(unp); unp2 = so2->so_pcb; KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); UNP_PCB_LOCK(unp2); error = unp_connect2(so1, so2, PRU_CONNECT2); UNP_PCB_UNLOCK(unp2); UNP_PCB_UNLOCK(unp); UNP_GLOBAL_WUNLOCK(); return (error); } /* control is EOPNOTSUPP */ static void uipc_detach(struct socket *so) { struct unpcb *unp, *unp2; struct sockaddr_un *saved_unp_addr; struct vnode *vp; int freeunp, local_unp_rights; unp = sotounpcb(so); KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); UNP_GLOBAL_WLOCK(); UNP_PCB_LOCK(unp); LIST_REMOVE(unp, unp_link); unp->unp_gencnt = ++unp_gencnt; --unp_count; /* * XXXRW: Should assert vp->v_socket == so. */ if ((vp = unp->unp_vnode) != NULL) { unp->unp_vnode->v_socket = NULL; unp->unp_vnode = NULL; } unp2 = unp->unp_conn; if (unp2 != NULL) { UNP_PCB_LOCK(unp2); unp_disconnect(unp, unp2); UNP_PCB_UNLOCK(unp2); } /* * We hold the global lock, so it's OK to acquire multiple pcb locks * at a time. */ while (!LIST_EMPTY(&unp->unp_refs)) { struct unpcb *ref = LIST_FIRST(&unp->unp_refs); UNP_PCB_LOCK(ref); unp_drop(ref, ECONNRESET); UNP_PCB_UNLOCK(ref); } local_unp_rights = unp_rights; UNP_GLOBAL_WUNLOCK(); unp->unp_socket->so_pcb = NULL; saved_unp_addr = unp->unp_addr; unp->unp_addr = NULL; unp->unp_refcount--; freeunp = (unp->unp_refcount == 0); if (saved_unp_addr != NULL) FREE(saved_unp_addr, M_SONAME); if (freeunp) { UNP_PCB_LOCK_DESTROY(unp); uma_zfree(unp_zone, unp); } else UNP_PCB_UNLOCK(unp); if (vp) { int vfslocked; vfslocked = VFS_LOCK_GIANT(vp->v_mount); vrele(vp); VFS_UNLOCK_GIANT(vfslocked); } if (local_unp_rights) taskqueue_enqueue(taskqueue_thread, &unp_gc_task); } static int uipc_disconnect(struct socket *so) { struct unpcb *unp, *unp2; unp = sotounpcb(so); KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); UNP_GLOBAL_WLOCK(); UNP_PCB_LOCK(unp); unp2 = unp->unp_conn; if (unp2 != NULL) { UNP_PCB_LOCK(unp2); unp_disconnect(unp, unp2); UNP_PCB_UNLOCK(unp2); } UNP_PCB_UNLOCK(unp); UNP_GLOBAL_WUNLOCK(); return (0); } static int uipc_listen(struct socket *so, int backlog, struct thread *td) { struct unpcb *unp; int error; unp = sotounpcb(so); KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); UNP_PCB_LOCK(unp); if (unp->unp_vnode == NULL) { UNP_PCB_UNLOCK(unp); return (EINVAL); } SOCK_LOCK(so); error = solisten_proto_check(so); if (error == 0) { cru2x(td->td_ucred, &unp->unp_peercred); unp->unp_flags |= UNP_HAVEPCCACHED; solisten_proto(so, backlog); } SOCK_UNLOCK(so); UNP_PCB_UNLOCK(unp); return (error); } static int uipc_peeraddr(struct socket *so, struct sockaddr **nam) { struct unpcb *unp, *unp2; const struct sockaddr *sa; unp = sotounpcb(so); KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); UNP_PCB_LOCK(unp); /* * XXX: It seems that this test always fails even when connection is * established. So, this else clause is added as workaround to * return PF_LOCAL sockaddr. */ unp2 = unp->unp_conn; if (unp2 != NULL) { UNP_PCB_LOCK(unp2); if (unp2->unp_addr != NULL) sa = (struct sockaddr *) unp->unp_conn->unp_addr; else sa = &sun_noname; bcopy(sa, *nam, sa->sa_len); UNP_PCB_UNLOCK(unp2); } else { sa = &sun_noname; bcopy(sa, *nam, sa->sa_len); } UNP_PCB_UNLOCK(unp); return (0); } static int uipc_rcvd(struct socket *so, int flags) { struct unpcb *unp, *unp2; struct socket *so2; u_int mbcnt, sbcc; u_long newhiwat; unp = sotounpcb(so); KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL")); if (so->so_type == SOCK_DGRAM) panic("uipc_rcvd DGRAM?"); if (so->so_type != SOCK_STREAM) panic("uipc_rcvd unknown socktype"); /* * Adjust backpressure on sender and wakeup any waiting to write. * * The unp lock is acquired to maintain the validity of the unp_conn * pointer; no lock on unp2 is required as unp2->unp_socket will be * static as long as we don't permit unp2 to disconnect from unp, * which is prevented by the lock on unp. We cache values from * so_rcv to avoid holding the so_rcv lock over the entire * transaction on the remote so_snd. */ SOCKBUF_LOCK(&so->so_rcv); mbcnt = so->so_rcv.sb_mbcnt; sbcc = so->so_rcv.sb_cc; SOCKBUF_UNLOCK(&so->so_rcv); UNP_PCB_LOCK(unp); unp2 = unp->unp_conn; if (unp2 == NULL) { UNP_PCB_UNLOCK(unp); return (0); } so2 = unp2->unp_socket; SOCKBUF_LOCK(&so2->so_snd); so2->so_snd.sb_mbmax += unp->unp_mbcnt - mbcnt; newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - sbcc; (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat, newhiwat, RLIM_INFINITY); sowwakeup_locked(so2); unp->unp_mbcnt = mbcnt; unp->unp_cc = sbcc; UNP_PCB_UNLOCK(unp); return (0); } /* pru_rcvoob is EOPNOTSUPP */ static int uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, struct mbuf *control, struct thread *td) { struct unpcb *unp, *unp2; struct socket *so2; u_int mbcnt, sbcc; u_long newhiwat; int error = 0; unp = sotounpcb(so); KASSERT(unp != NULL, ("uipc_send: unp == NULL")); if (flags & PRUS_OOB) { error = EOPNOTSUPP; goto release; } if (control != NULL && (error = unp_internalize(&control, td))) goto release; if ((nam != NULL) || (flags & PRUS_EOF)) UNP_GLOBAL_WLOCK(); else UNP_GLOBAL_RLOCK(); switch (so->so_type) { case SOCK_DGRAM: { const struct sockaddr *from; unp2 = unp->unp_conn; if (nam != NULL) { UNP_GLOBAL_WLOCK_ASSERT(); if (unp2 != NULL) { error = EISCONN; break; } error = unp_connect(so, nam, td); if (error) break; unp2 = unp->unp_conn; } /* * Because connect() and send() are non-atomic in a sendto() * with a target address, it's possible that the socket will * have disconnected before the send() can run. In that case * return the slightly counter-intuitive but otherwise * correct error that the socket is not connected. */ if (unp2 == NULL) { error = ENOTCONN; break; } /* Lockless read. */ if (unp2->unp_flags & UNP_WANTCRED) control = unp_addsockcred(td, control); UNP_PCB_LOCK(unp); if (unp->unp_addr != NULL) from = (struct sockaddr *)unp->unp_addr; else from = &sun_noname; so2 = unp2->unp_socket; SOCKBUF_LOCK(&so2->so_rcv); if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) { sorwakeup_locked(so2); m = NULL; control = NULL; } else { SOCKBUF_UNLOCK(&so2->so_rcv); error = ENOBUFS; } if (nam != NULL) { UNP_GLOBAL_WLOCK_ASSERT(); UNP_PCB_LOCK(unp2); unp_disconnect(unp, unp2); UNP_PCB_UNLOCK(unp2); } UNP_PCB_UNLOCK(unp); break; } case SOCK_STREAM: /* * Connect if not connected yet. * * Note: A better implementation would complain if not equal * to the peer's address. */ if ((so->so_state & SS_ISCONNECTED) == 0) { if (nam != NULL) { UNP_GLOBAL_WLOCK_ASSERT(); error = unp_connect(so, nam, td); if (error) break; /* XXX */ } else { error = ENOTCONN; break; } } /* Lockless read. */ if (so->so_snd.sb_state & SBS_CANTSENDMORE) { error = EPIPE; break; } /* * Because connect() and send() are non-atomic in a sendto() * with a target address, it's possible that the socket will * have disconnected before the send() can run. In that case * return the slightly counter-intuitive but otherwise * correct error that the socket is not connected. * * Locking here must be done carefully: the global lock * prevents interconnections between unpcbs from changing, so * we can traverse from unp to unp2 without acquiring unp's * lock. Socket buffer locks follow unpcb locks, so we can * acquire both remote and lock socket buffer locks. */ unp2 = unp->unp_conn; if (unp2 == NULL) { error = ENOTCONN; break; } so2 = unp2->unp_socket; UNP_PCB_LOCK(unp2); SOCKBUF_LOCK(&so2->so_rcv); if (unp2->unp_flags & UNP_WANTCRED) { /* * Credentials are passed only once on SOCK_STREAM. */ unp2->unp_flags &= ~UNP_WANTCRED; control = unp_addsockcred(td, control); } /* * Send to paired receive port, and then reduce send buffer * hiwater marks to maintain backpressure. Wake up readers. */ if (control != NULL) { if (sbappendcontrol_locked(&so2->so_rcv, m, control)) control = NULL; } else sbappend_locked(&so2->so_rcv, m); mbcnt = so2->so_rcv.sb_mbcnt - unp2->unp_mbcnt; unp2->unp_mbcnt = so2->so_rcv.sb_mbcnt; sbcc = so2->so_rcv.sb_cc; sorwakeup_locked(so2); SOCKBUF_LOCK(&so->so_snd); newhiwat = so->so_snd.sb_hiwat - (sbcc - unp2->unp_cc); (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat, newhiwat, RLIM_INFINITY); so->so_snd.sb_mbmax -= mbcnt; SOCKBUF_UNLOCK(&so->so_snd); unp2->unp_cc = sbcc; UNP_PCB_UNLOCK(unp2); m = NULL; break; default: panic("uipc_send unknown socktype"); } /* * SEND_EOF is equivalent to a SEND followed by a SHUTDOWN. */ if (flags & PRUS_EOF) { UNP_PCB_LOCK(unp); socantsendmore(so); unp_shutdown(unp); UNP_PCB_UNLOCK(unp); } if ((nam != NULL) || (flags & PRUS_EOF)) UNP_GLOBAL_WUNLOCK(); else UNP_GLOBAL_RUNLOCK(); if (control != NULL && error != 0) unp_dispose(control); release: if (control != NULL) m_freem(control); if (m != NULL) m_freem(m); return (error); } static int uipc_sense(struct socket *so, struct stat *sb) { struct unpcb *unp, *unp2; struct socket *so2; unp = sotounpcb(so); KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); sb->st_blksize = so->so_snd.sb_hiwat; UNP_GLOBAL_RLOCK(); UNP_PCB_LOCK(unp); unp2 = unp->unp_conn; if (so->so_type == SOCK_STREAM && unp2 != NULL) { so2 = unp2->unp_socket; sb->st_blksize += so2->so_rcv.sb_cc; } sb->st_dev = NODEV; if (unp->unp_ino == 0) unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; sb->st_ino = unp->unp_ino; UNP_PCB_UNLOCK(unp); UNP_GLOBAL_RUNLOCK(); return (0); } static int uipc_shutdown(struct socket *so) { struct unpcb *unp; unp = sotounpcb(so); KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); UNP_GLOBAL_WLOCK(); UNP_PCB_LOCK(unp); socantsendmore(so); unp_shutdown(unp); UNP_PCB_UNLOCK(unp); UNP_GLOBAL_WUNLOCK(); return (0); } static int uipc_sockaddr(struct socket *so, struct sockaddr **nam) { struct unpcb *unp; const struct sockaddr *sa; unp = sotounpcb(so); KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); UNP_PCB_LOCK(unp); if (unp->unp_addr != NULL) sa = (struct sockaddr *) unp->unp_addr; else sa = &sun_noname; bcopy(sa, *nam, sa->sa_len); UNP_PCB_UNLOCK(unp); return (0); } struct pr_usrreqs uipc_usrreqs = { .pru_abort = uipc_abort, .pru_accept = uipc_accept, .pru_attach = uipc_attach, .pru_bind = uipc_bind, .pru_connect = uipc_connect, .pru_connect2 = uipc_connect2, .pru_detach = uipc_detach, .pru_disconnect = uipc_disconnect, .pru_listen = uipc_listen, .pru_peeraddr = uipc_peeraddr, .pru_rcvd = uipc_rcvd, .pru_send = uipc_send, .pru_sense = uipc_sense, .pru_shutdown = uipc_shutdown, .pru_sockaddr = uipc_sockaddr, .pru_close = uipc_close, }; int uipc_ctloutput(struct socket *so, struct sockopt *sopt) { struct unpcb *unp; struct xucred xu; int error, optval; if (sopt->sopt_level != 0) return (EINVAL); unp = sotounpcb(so); KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); error = 0; switch (sopt->sopt_dir) { case SOPT_GET: switch (sopt->sopt_name) { case LOCAL_PEERCRED: UNP_PCB_LOCK(unp); if (unp->unp_flags & UNP_HAVEPC) xu = unp->unp_peercred; else { if (so->so_type == SOCK_STREAM) error = ENOTCONN; else error = EINVAL; } UNP_PCB_UNLOCK(unp); if (error == 0) error = sooptcopyout(sopt, &xu, sizeof(xu)); break; case LOCAL_CREDS: /* Unocked read. */ optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; error = sooptcopyout(sopt, &optval, sizeof(optval)); break; case LOCAL_CONNWAIT: /* Unocked read. */ optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; error = sooptcopyout(sopt, &optval, sizeof(optval)); break; default: error = EOPNOTSUPP; break; } break; case SOPT_SET: switch (sopt->sopt_name) { case LOCAL_CREDS: case LOCAL_CONNWAIT: error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval)); if (error) break; #define OPTSET(bit) do { \ UNP_PCB_LOCK(unp); \ if (optval) \ unp->unp_flags |= bit; \ else \ unp->unp_flags &= ~bit; \ UNP_PCB_UNLOCK(unp); \ } while (0) switch (sopt->sopt_name) { case LOCAL_CREDS: OPTSET(UNP_WANTCRED); break; case LOCAL_CONNWAIT: OPTSET(UNP_CONNWAIT); break; default: break; } break; #undef OPTSET default: error = ENOPROTOOPT; break; } break; default: error = EOPNOTSUPP; break; } return (error); } static int unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) { struct sockaddr_un *soun = (struct sockaddr_un *)nam; struct vnode *vp; struct socket *so2, *so3; struct unpcb *unp, *unp2, *unp3; int error, len, vfslocked; struct nameidata nd; char buf[SOCK_MAXADDRLEN]; struct sockaddr *sa; UNP_GLOBAL_WLOCK_ASSERT(); UNP_GLOBAL_WUNLOCK(); unp = sotounpcb(so); KASSERT(unp != NULL, ("unp_connect: unp == NULL")); len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); if (len <= 0) return (EINVAL); strlcpy(buf, soun->sun_path, len + 1); UNP_PCB_LOCK(unp); if (unp->unp_flags & UNP_CONNECTING) { UNP_PCB_UNLOCK(unp); return (EALREADY); } unp->unp_flags |= UNP_CONNECTING; UNP_PCB_UNLOCK(unp); sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKLEAF, UIO_SYSSPACE, buf, td); error = namei(&nd); if (error) vp = NULL; else vp = nd.ni_vp; ASSERT_VOP_LOCKED(vp, "unp_connect"); vfslocked = NDHASGIANT(&nd); NDFREE(&nd, NDF_ONLY_PNBUF); if (error) goto bad; if (vp->v_type != VSOCK) { error = ENOTSOCK; goto bad; } #ifdef MAC error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); if (error) goto bad; #endif error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); if (error) goto bad; VFS_UNLOCK_GIANT(vfslocked); unp = sotounpcb(so); KASSERT(unp != NULL, ("unp_connect: unp == NULL")); /* * Lock global lock for two reasons: make sure v_socket is stable, * and to protect simultaneous locking of multiple pcbs. */ UNP_GLOBAL_WLOCK(); so2 = vp->v_socket; if (so2 == NULL) { error = ECONNREFUSED; goto bad2; } if (so->so_type != so2->so_type) { error = EPROTOTYPE; goto bad2; } if (so->so_proto->pr_flags & PR_CONNREQUIRED) { if (so2->so_options & SO_ACCEPTCONN) { /* * We can't drop the global lock here or 'so2' may * become invalid. As a result, we need to handle * possibly lock recursion in uipc_attach. */ so3 = sonewconn(so2, 0); } else so3 = NULL; if (so3 == NULL) { error = ECONNREFUSED; goto bad2; } unp = sotounpcb(so); unp2 = sotounpcb(so2); unp3 = sotounpcb(so3); UNP_PCB_LOCK(unp); UNP_PCB_LOCK(unp2); UNP_PCB_LOCK(unp3); if (unp2->unp_addr != NULL) { bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); unp3->unp_addr = (struct sockaddr_un *) sa; sa = NULL; } /* * unp_peercred management: * * The connecter's (client's) credentials are copied from its * process structure at the time of connect() (which is now). */ cru2x(td->td_ucred, &unp3->unp_peercred); unp3->unp_flags |= UNP_HAVEPC; /* * The receiver's (server's) credentials are copied from the * unp_peercred member of socket on which the former called * listen(); uipc_listen() cached that process's credentials * at that time so we can use them now. */ KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, ("unp_connect: listener without cached peercred")); memcpy(&unp->unp_peercred, &unp2->unp_peercred, sizeof(unp->unp_peercred)); unp->unp_flags |= UNP_HAVEPC; if (unp2->unp_flags & UNP_WANTCRED) unp3->unp_flags |= UNP_WANTCRED; UNP_PCB_UNLOCK(unp3); UNP_PCB_UNLOCK(unp2); UNP_PCB_UNLOCK(unp); #ifdef MAC SOCK_LOCK(so); mac_socketpeer_set_from_socket(so, so3); mac_socketpeer_set_from_socket(so3, so); SOCK_UNLOCK(so); #endif so2 = so3; } unp = sotounpcb(so); KASSERT(unp != NULL, ("unp_connect: unp == NULL")); unp2 = sotounpcb(so2); KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL")); UNP_PCB_LOCK(unp); UNP_PCB_LOCK(unp2); error = unp_connect2(so, so2, PRU_CONNECT); UNP_PCB_UNLOCK(unp2); UNP_PCB_UNLOCK(unp); bad2: UNP_GLOBAL_WUNLOCK(); if (vfslocked) /* * Giant has been previously acquired. This means filesystem * isn't MPSAFE. Do it once again. */ mtx_lock(&Giant); bad: if (vp != NULL) vput(vp); VFS_UNLOCK_GIANT(vfslocked); free(sa, M_SONAME); UNP_GLOBAL_WLOCK(); UNP_PCB_LOCK(unp); unp->unp_flags &= ~UNP_CONNECTING; UNP_PCB_UNLOCK(unp); return (error); } static int unp_connect2(struct socket *so, struct socket *so2, int req) { struct unpcb *unp; struct unpcb *unp2; unp = sotounpcb(so); KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); unp2 = sotounpcb(so2); KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); UNP_GLOBAL_WLOCK_ASSERT(); UNP_PCB_LOCK_ASSERT(unp); UNP_PCB_LOCK_ASSERT(unp2); if (so2->so_type != so->so_type) return (EPROTOTYPE); unp->unp_conn = unp2; switch (so->so_type) { case SOCK_DGRAM: LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); soisconnected(so); break; case SOCK_STREAM: unp2->unp_conn = unp; if (req == PRU_CONNECT && ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) soisconnecting(so); else soisconnected(so); soisconnected(so2); break; default: panic("unp_connect2"); } return (0); } static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2) { struct socket *so; KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); UNP_GLOBAL_WLOCK_ASSERT(); UNP_PCB_LOCK_ASSERT(unp); UNP_PCB_LOCK_ASSERT(unp2); unp->unp_conn = NULL; switch (unp->unp_socket->so_type) { case SOCK_DGRAM: LIST_REMOVE(unp, unp_reflink); so = unp->unp_socket; SOCK_LOCK(so); so->so_state &= ~SS_ISCONNECTED; SOCK_UNLOCK(so); break; case SOCK_STREAM: soisdisconnected(unp->unp_socket); unp2->unp_conn = NULL; soisdisconnected(unp2->unp_socket); break; } } /* * unp_pcblist() walks the global list of struct unpcb's to generate a * pointer list, bumping the refcount on each unpcb. It then copies them out * sequentially, validating the generation number on each to see if it has * been detached. All of this is necessary because copyout() may sleep on * disk I/O. */ static int unp_pcblist(SYSCTL_HANDLER_ARGS) { int error, i, n; int freeunp; struct unpcb *unp, **unp_list; unp_gen_t gencnt; struct xunpgen *xug; struct unp_head *head; struct xunpcb *xu; head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead); /* * The process of preparing the PCB list is too time-consuming and * resource-intensive to repeat twice on every request. */ if (req->oldptr == NULL) { n = unp_count; req->oldidx = 2 * (sizeof *xug) + (n + n/8) * sizeof(struct xunpcb); return (0); } if (req->newptr != NULL) return (EPERM); /* * OK, now we're committed to doing something. */ xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); UNP_GLOBAL_RLOCK(); gencnt = unp_gencnt; n = unp_count; UNP_GLOBAL_RUNLOCK(); xug->xug_len = sizeof *xug; xug->xug_count = n; xug->xug_gen = gencnt; xug->xug_sogen = so_gencnt; error = SYSCTL_OUT(req, xug, sizeof *xug); if (error) { free(xug, M_TEMP); return (error); } unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); UNP_GLOBAL_RLOCK(); for (unp = LIST_FIRST(head), i = 0; unp && i < n; unp = LIST_NEXT(unp, unp_link)) { UNP_PCB_LOCK(unp); if (unp->unp_gencnt <= gencnt) { if (cr_cansee(req->td->td_ucred, unp->unp_socket->so_cred)) { UNP_PCB_UNLOCK(unp); continue; } unp_list[i++] = unp; unp->unp_refcount++; } UNP_PCB_UNLOCK(unp); } UNP_GLOBAL_RUNLOCK(); n = i; /* In case we lost some during malloc. */ error = 0; xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); for (i = 0; i < n; i++) { unp = unp_list[i]; UNP_PCB_LOCK(unp); unp->unp_refcount--; if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) { xu->xu_len = sizeof *xu; xu->xu_unpp = unp; /* * XXX - need more locking here to protect against * connect/disconnect races for SMP. */ if (unp->unp_addr != NULL) bcopy(unp->unp_addr, &xu->xu_addr, unp->unp_addr->sun_len); if (unp->unp_conn != NULL && unp->unp_conn->unp_addr != NULL) bcopy(unp->unp_conn->unp_addr, &xu->xu_caddr, unp->unp_conn->unp_addr->sun_len); bcopy(unp, &xu->xu_unp, sizeof *unp); sotoxsocket(unp->unp_socket, &xu->xu_socket); UNP_PCB_UNLOCK(unp); error = SYSCTL_OUT(req, xu, sizeof *xu); } else { freeunp = (unp->unp_refcount == 0); UNP_PCB_UNLOCK(unp); if (freeunp) { UNP_PCB_LOCK_DESTROY(unp); uma_zfree(unp_zone, unp); } } } free(xu, M_TEMP); if (!error) { /* * Give the user an updated idea of our state. If the * generation differs from what we told her before, she knows * that something happened while we were processing this * request, and it might be necessary to retry. */ xug->xug_gen = unp_gencnt; xug->xug_sogen = so_gencnt; xug->xug_count = unp_count; error = SYSCTL_OUT(req, xug, sizeof *xug); } free(unp_list, M_TEMP); free(xug, M_TEMP); return (error); } SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD, (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", "List of active local datagram sockets"); SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD, (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", "List of active local stream sockets"); static void unp_shutdown(struct unpcb *unp) { struct unpcb *unp2; struct socket *so; UNP_GLOBAL_WLOCK_ASSERT(); UNP_PCB_LOCK_ASSERT(unp); unp2 = unp->unp_conn; if (unp->unp_socket->so_type == SOCK_STREAM && unp2 != NULL) { so = unp2->unp_socket; if (so != NULL) socantrcvmore(so); } } static void unp_drop(struct unpcb *unp, int errno) { struct socket *so = unp->unp_socket; struct unpcb *unp2; UNP_GLOBAL_WLOCK_ASSERT(); UNP_PCB_LOCK_ASSERT(unp); so->so_error = errno; unp2 = unp->unp_conn; if (unp2 == NULL) return; UNP_PCB_LOCK(unp2); unp_disconnect(unp, unp2); UNP_PCB_UNLOCK(unp2); } static void unp_freerights(struct file **rp, int fdcount) { int i; struct file *fp; for (i = 0; i < fdcount; i++) { /* * Zero the pointer before calling unp_discard since it may * end up in unp_gc().. * * XXXRW: This is less true than it used to be. */ fp = *rp; *rp++ = NULL; unp_discard(fp); } } int unp_externalize(struct mbuf *control, struct mbuf **controlp) { struct thread *td = curthread; /* XXX */ struct cmsghdr *cm = mtod(control, struct cmsghdr *); int i; int *fdp; struct file **rp; struct file *fp; void *data; socklen_t clen = control->m_len, datalen; int error, newfds; int f; u_int newlen; UNP_GLOBAL_UNLOCK_ASSERT(); error = 0; if (controlp != NULL) /* controlp == NULL => free control messages */ *controlp = NULL; while (cm != NULL) { if (sizeof(*cm) > clen || cm->cmsg_len > clen) { error = EINVAL; break; } data = CMSG_DATA(cm); datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; if (cm->cmsg_level == SOL_SOCKET && cm->cmsg_type == SCM_RIGHTS) { newfds = datalen / sizeof(struct file *); rp = data; /* If we're not outputting the descriptors free them. */ if (error || controlp == NULL) { unp_freerights(rp, newfds); goto next; } FILEDESC_XLOCK(td->td_proc->p_fd); /* if the new FD's will not fit free them. */ if (!fdavail(td, newfds)) { FILEDESC_XUNLOCK(td->td_proc->p_fd); error = EMSGSIZE; unp_freerights(rp, newfds); goto next; } /* * Now change each pointer to an fd in the global * table to an integer that is the index to the local * fd table entry that we set up to point to the * global one we are transferring. */ newlen = newfds * sizeof(int); *controlp = sbcreatecontrol(NULL, newlen, SCM_RIGHTS, SOL_SOCKET); if (*controlp == NULL) { FILEDESC_XUNLOCK(td->td_proc->p_fd); error = E2BIG; unp_freerights(rp, newfds); goto next; } fdp = (int *) CMSG_DATA(mtod(*controlp, struct cmsghdr *)); for (i = 0; i < newfds; i++) { if (fdalloc(td, 0, &f)) panic("unp_externalize fdalloc failed"); fp = *rp++; td->td_proc->p_fd->fd_ofiles[f] = fp; unp_externalize_fp(fp); *fdp++ = f; } FILEDESC_XUNLOCK(td->td_proc->p_fd); } else { /* We can just copy anything else across. */ if (error || controlp == NULL) goto next; *controlp = sbcreatecontrol(NULL, datalen, cm->cmsg_type, cm->cmsg_level); if (*controlp == NULL) { error = ENOBUFS; goto next; } bcopy(data, CMSG_DATA(mtod(*controlp, struct cmsghdr *)), datalen); } controlp = &(*controlp)->m_next; next: if (CMSG_SPACE(datalen) < clen) { clen -= CMSG_SPACE(datalen); cm = (struct cmsghdr *) ((caddr_t)cm + CMSG_SPACE(datalen)); } else { clen = 0; cm = NULL; } } m_freem(control); return (error); } static void unp_zone_change(void *tag) { uma_zone_set_max(unp_zone, maxsockets); } void unp_init(void) { unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); if (unp_zone == NULL) panic("unp_init"); uma_zone_set_max(unp_zone, maxsockets); EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, NULL, EVENTHANDLER_PRI_ANY); LIST_INIT(&unp_dhead); LIST_INIT(&unp_shead); TASK_INIT(&unp_gc_task, 0, unp_gc, NULL); UNP_GLOBAL_LOCK_INIT(); } static int unp_internalize(struct mbuf **controlp, struct thread *td) { struct mbuf *control = *controlp; struct proc *p = td->td_proc; struct filedesc *fdescp = p->p_fd; struct cmsghdr *cm = mtod(control, struct cmsghdr *); struct cmsgcred *cmcred; struct file **rp; struct file *fp; struct timeval *tv; int i, fd, *fdp; void *data; socklen_t clen = control->m_len, datalen; int error, oldfds; u_int newlen; UNP_GLOBAL_UNLOCK_ASSERT(); error = 0; *controlp = NULL; while (cm != NULL) { if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET || cm->cmsg_len > clen) { error = EINVAL; goto out; } data = CMSG_DATA(cm); datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; switch (cm->cmsg_type) { /* * Fill in credential information. */ case SCM_CREDS: *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), SCM_CREDS, SOL_SOCKET); if (*controlp == NULL) { error = ENOBUFS; goto out; } cmcred = (struct cmsgcred *) CMSG_DATA(mtod(*controlp, struct cmsghdr *)); cmcred->cmcred_pid = p->p_pid; cmcred->cmcred_uid = td->td_ucred->cr_ruid; cmcred->cmcred_gid = td->td_ucred->cr_rgid; cmcred->cmcred_euid = td->td_ucred->cr_uid; cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); for (i = 0; i < cmcred->cmcred_ngroups; i++) cmcred->cmcred_groups[i] = td->td_ucred->cr_groups[i]; break; case SCM_RIGHTS: oldfds = datalen / sizeof (int); /* * Check that all the FDs passed in refer to legal * files. If not, reject the entire operation. */ fdp = data; FILEDESC_SLOCK(fdescp); for (i = 0; i < oldfds; i++) { fd = *fdp++; if ((unsigned)fd >= fdescp->fd_nfiles || fdescp->fd_ofiles[fd] == NULL) { FILEDESC_SUNLOCK(fdescp); error = EBADF; goto out; } fp = fdescp->fd_ofiles[fd]; if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { FILEDESC_SUNLOCK(fdescp); error = EOPNOTSUPP; goto out; } } /* * Now replace the integer FDs with pointers to * the associated global file table entry.. */ newlen = oldfds * sizeof(struct file *); *controlp = sbcreatecontrol(NULL, newlen, SCM_RIGHTS, SOL_SOCKET); if (*controlp == NULL) { FILEDESC_SUNLOCK(fdescp); error = E2BIG; goto out; } fdp = data; rp = (struct file **) CMSG_DATA(mtod(*controlp, struct cmsghdr *)); for (i = 0; i < oldfds; i++) { fp = fdescp->fd_ofiles[*fdp++]; *rp++ = fp; fhold(fp); unp_internalize_fp(fp); } FILEDESC_SUNLOCK(fdescp); break; case SCM_TIMESTAMP: *controlp = sbcreatecontrol(NULL, sizeof(*tv), SCM_TIMESTAMP, SOL_SOCKET); if (*controlp == NULL) { error = ENOBUFS; goto out; } tv = (struct timeval *) CMSG_DATA(mtod(*controlp, struct cmsghdr *)); microtime(tv); break; default: error = EINVAL; goto out; } controlp = &(*controlp)->m_next; if (CMSG_SPACE(datalen) < clen) { clen -= CMSG_SPACE(datalen); cm = (struct cmsghdr *) ((caddr_t)cm + CMSG_SPACE(datalen)); } else { clen = 0; cm = NULL; } } out: m_freem(control); return (error); } static struct mbuf * unp_addsockcred(struct thread *td, struct mbuf *control) { struct mbuf *m, *n, *n_prev; struct sockcred *sc; const struct cmsghdr *cm; int ngroups; int i; ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); if (m == NULL) return (control); sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); sc->sc_uid = td->td_ucred->cr_ruid; sc->sc_euid = td->td_ucred->cr_uid; sc->sc_gid = td->td_ucred->cr_rgid; sc->sc_egid = td->td_ucred->cr_gid; sc->sc_ngroups = ngroups; for (i = 0; i < sc->sc_ngroups; i++) sc->sc_groups[i] = td->td_ucred->cr_groups[i]; /* * Unlink SCM_CREDS control messages (struct cmsgcred), since just * created SCM_CREDS control message (struct sockcred) has another * format. */ if (control != NULL) for (n = control, n_prev = NULL; n != NULL;) { cm = mtod(n, struct cmsghdr *); if (cm->cmsg_level == SOL_SOCKET && cm->cmsg_type == SCM_CREDS) { if (n_prev == NULL) control = n->m_next; else n_prev->m_next = n->m_next; n = m_free(n); } else { n_prev = n; n = n->m_next; } } /* Prepend it to the head. */ m->m_next = control; return (m); } 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 != &localdomain) return (NULL); return sotounpcb(so); } static void unp_discard(struct file *fp) { unp_externalize_fp(fp); (void) closef(fp, (struct thread *)NULL); } static void unp_internalize_fp(struct file *fp) { struct unpcb *unp; UNP_GLOBAL_WLOCK(); if ((unp = fptounp(fp)) != NULL) { unp->unp_file = fp; unp->unp_msgcount++; } unp_rights++; UNP_GLOBAL_WUNLOCK(); } static void unp_externalize_fp(struct file *fp) { struct unpcb *unp; UNP_GLOBAL_WLOCK(); if ((unp = fptounp(fp)) != NULL) unp->unp_msgcount--; unp_rights--; UNP_GLOBAL_WUNLOCK(); } /* * unp_defer indicates whether additional work has been defered for a future * pass through unp_gc(). It is thread local and does not require explicit * synchronization. */ static int unp_marked; static int unp_unreachable; static void unp_accessable(struct file *fp) { struct unpcb *unp; unp = fptounp(fp); if (fp == NULL) return; if (unp->unp_gcflag & UNPGC_REF) return; unp->unp_gcflag &= ~UNPGC_DEAD; unp->unp_gcflag |= UNPGC_REF; unp_marked++; } static void unp_gc_process(struct unpcb *unp) { struct socket *soa; struct socket *so; struct file *fp; /* Already processed. */ if (unp->unp_gcflag & UNPGC_SCANNED) return; fp = unp->unp_file; /* * Check for a socket potentially in a cycle. It must be in a * queue as indicated by msgcount, and this must equal the file * reference count. Note that when msgcount is 0 the file is NULL. */ if (unp->unp_msgcount != 0 && fp->f_count != 0 && fp->f_count == unp->unp_msgcount) { unp->unp_gcflag |= UNPGC_DEAD; unp_unreachable++; return; } /* * Mark all sockets we reference with RIGHTS. */ so = unp->unp_socket; SOCKBUF_LOCK(&so->so_rcv); unp_scan(so->so_rcv.sb_mb, unp_accessable); SOCKBUF_UNLOCK(&so->so_rcv); /* * Mark all sockets in our accept queue. */ ACCEPT_LOCK(); TAILQ_FOREACH(soa, &so->so_comp, so_list) { SOCKBUF_LOCK(&soa->so_rcv); unp_scan(soa->so_rcv.sb_mb, unp_accessable); SOCKBUF_UNLOCK(&soa->so_rcv); } ACCEPT_UNLOCK(); unp->unp_gcflag |= UNPGC_SCANNED; } static int unp_recycled; SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, ""); static int unp_taskcount; SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, ""); static void unp_gc(__unused void *arg, int pending) { struct unp_head *heads[] = { &unp_dhead, &unp_shead, NULL }; struct unp_head **head; struct file **unref; struct unpcb *unp; int i; unp_taskcount++; UNP_GLOBAL_RLOCK(); /* * First clear all gc flags from previous runs. */ for (head = heads; *head != NULL; head++) LIST_FOREACH(unp, *head, unp_link) unp->unp_gcflag &= ~(UNPGC_REF|UNPGC_DEAD); /* * Scan marking all reachable sockets with UNPGC_REF. Once a socket * is reachable all of the sockets it references are reachable. * Stop the scan once we do a complete loop without discovering * a new reachable socket. */ do { unp_unreachable = 0; unp_marked = 0; for (head = heads; *head != NULL; head++) LIST_FOREACH(unp, *head, unp_link) unp_gc_process(unp); } while (unp_marked); UNP_GLOBAL_RUNLOCK(); if (unp_unreachable == 0) return; /* * Allocate space for a local list of dead unpcbs. */ unref = malloc(unp_unreachable * sizeof(struct file *), M_TEMP, M_WAITOK); /* * Iterate looking for sockets which have been specifically marked * as as unreachable and store them locally. */ UNP_GLOBAL_RLOCK(); for (i = 0, head = heads; *head != NULL; head++) LIST_FOREACH(unp, *head, unp_link) if (unp->unp_gcflag & UNPGC_DEAD) { unref[i++] = unp->unp_file; KASSERT(unp->unp_file != NULL, ("unp_gc: Invalid unpcb.")); KASSERT(i <= unp_unreachable, ("unp_gc: incorrect unreachable count.")); } UNP_GLOBAL_RUNLOCK(); /* * All further operation is now done on a local list. We first ref * all sockets to avoid closing them until all are flushed. */ for (i = 0; i < unp_unreachable; i++) fhold(unref[i]); /* * Now flush all sockets, free'ing rights. This will free the * struct files associated with these sockets but leave each socket * with one remaining ref. */ for (i = 0; i < unp_unreachable; i++) sorflush(unref[i]->f_data); /* * And finally release the sockets so they can be reclaimed. */ for (i = 0; i < unp_unreachable; i++) fdrop(unref[i], NULL); unp_recycled += unp_unreachable; free(unref, M_TEMP); } void unp_dispose(struct mbuf *m) { if (m) unp_scan(m, unp_discard); } static void unp_scan(struct mbuf *m0, void (*op)(struct file *)) { struct mbuf *m; struct file **rp; struct cmsghdr *cm; void *data; int i; socklen_t clen, datalen; int qfds; while (m0 != NULL) { for (m = m0; m; m = m->m_next) { if (m->m_type != MT_CONTROL) continue; cm = mtod(m, struct cmsghdr *); clen = m->m_len; while (cm != NULL) { if (sizeof(*cm) > clen || cm->cmsg_len > clen) break; data = CMSG_DATA(cm); datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; if (cm->cmsg_level == SOL_SOCKET && cm->cmsg_type == SCM_RIGHTS) { qfds = datalen / sizeof (struct file *); rp = data; for (i = 0; i < qfds; i++) (*op)(*rp++); } if (CMSG_SPACE(datalen) < clen) { clen -= CMSG_SPACE(datalen); cm = (struct cmsghdr *) ((caddr_t)cm + CMSG_SPACE(datalen)); } else { clen = 0; cm = NULL; } } } m0 = m0->m_act; } } #ifdef DDB static void db_print_indent(int indent) { int i; for (i = 0; i < indent; i++) db_printf(" "); } static void db_print_unpflags(int unp_flags) { int comma; comma = 0; if (unp_flags & UNP_HAVEPC) { db_printf("%sUNP_HAVEPC", comma ? ", " : ""); comma = 1; } if (unp_flags & UNP_HAVEPCCACHED) { db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : ""); comma = 1; } if (unp_flags & UNP_WANTCRED) { db_printf("%sUNP_WANTCRED", comma ? ", " : ""); comma = 1; } if (unp_flags & UNP_CONNWAIT) { db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); comma = 1; } if (unp_flags & UNP_CONNECTING) { db_printf("%sUNP_CONNECTING", comma ? ", " : ""); comma = 1; } if (unp_flags & UNP_BINDING) { db_printf("%sUNP_BINDING", comma ? ", " : ""); comma = 1; } } static void db_print_xucred(int indent, struct xucred *xu) { int comma, i; db_print_indent(indent); db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n", xu->cr_version, xu->cr_uid, xu->cr_ngroups); db_print_indent(indent); db_printf("cr_groups: "); comma = 0; for (i = 0; i < xu->cr_ngroups; i++) { db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); comma = 1; } db_printf("\n"); } static void db_print_unprefs(int indent, struct unp_head *uh) { struct unpcb *unp; int counter; counter = 0; LIST_FOREACH(unp, uh, unp_reflink) { if (counter % 4 == 0) db_print_indent(indent); db_printf("%p ", unp); if (counter % 4 == 3) db_printf("\n"); counter++; } if (counter != 0 && counter % 4 != 0) db_printf("\n"); } DB_SHOW_COMMAND(unpcb, db_show_unpcb) { struct unpcb *unp; if (!have_addr) { db_printf("usage: show unpcb \n"); return; } unp = (struct unpcb *)addr; db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, unp->unp_vnode); db_printf("unp_ino: %d unp_conn: %p\n", unp->unp_ino, unp->unp_conn); db_printf("unp_refs:\n"); db_print_unprefs(2, &unp->unp_refs); /* XXXRW: Would be nice to print the full address, if any. */ db_printf("unp_addr: %p\n", unp->unp_addr); db_printf("unp_cc: %d unp_mbcnt: %d unp_gencnt: %llu\n", unp->unp_cc, unp->unp_mbcnt, (unsigned long long)unp->unp_gencnt); db_printf("unp_flags: %x (", unp->unp_flags); db_print_unpflags(unp->unp_flags); db_printf(")\n"); db_printf("unp_peercred:\n"); db_print_xucred(2, &unp->unp_peercred); db_printf("unp_refcount: %u\n", unp->unp_refcount); } #endif