/* * Copyright (c) 2005 Jeffrey M. Hsu. All rights reserved. * Copyright (c) 1982, 1986, 1988, 1990, 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 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. * * @(#)uipc_socket2.c 8.1 (Berkeley) 6/10/93 * $FreeBSD: src/sys/kern/uipc_socket2.c,v 1.55.2.17 2002/08/31 19:04:55 dwmalone Exp $ * $DragonFly: src/sys/kern/uipc_socket2.c,v 1.28 2007/04/30 07:18:54 dillon Exp $ */ #include "opt_param.h" #include #include #include #include /* for maxfiles */ #include #include #include #include #include #include #include #include #include #include #include #include /* for aio_swake proto */ #include #include #include int maxsockets; /* * Primitive routines for operating on sockets and socket buffers */ u_long sb_max = SB_MAX; u_long sb_max_adj = SB_MAX * MCLBYTES / (MSIZE + MCLBYTES); /* adjusted sb_max */ static u_long sb_efficiency = 8; /* parameter for sbreserve() */ /************************************************************************ * signalsockbuf procedures * ************************************************************************/ /* * Wait for data to arrive at/drain from a socket buffer. */ int ssb_wait(struct signalsockbuf *ssb) { ssb->ssb_flags |= SSB_WAIT; return (tsleep((caddr_t)&ssb->ssb_cc, ((ssb->ssb_flags & SSB_NOINTR) ? 0 : PCATCH), "sbwait", ssb->ssb_timeo)); } /* * Lock a sockbuf already known to be locked; * return any error returned from sleep (EINTR). */ int _ssb_lock(struct signalsockbuf *ssb) { int error; while (ssb->ssb_flags & SSB_LOCK) { ssb->ssb_flags |= SSB_WANT; error = tsleep((caddr_t)&ssb->ssb_flags, ((ssb->ssb_flags & SSB_NOINTR) ? 0 : PCATCH), "sblock", 0); if (error) return (error); } ssb->ssb_flags |= SSB_LOCK; return (0); } /* * This does the same for sockbufs. Note that the xsockbuf structure, * since it is always embedded in a socket, does not include a self * pointer nor a length. We make this entry point public in case * some other mechanism needs it. */ void ssbtoxsockbuf(struct signalsockbuf *ssb, struct xsockbuf *xsb) { xsb->sb_cc = ssb->ssb_cc; xsb->sb_hiwat = ssb->ssb_hiwat; xsb->sb_mbcnt = ssb->ssb_mbcnt; xsb->sb_mbmax = ssb->ssb_mbmax; xsb->sb_lowat = ssb->ssb_lowat; xsb->sb_flags = ssb->ssb_flags; xsb->sb_timeo = ssb->ssb_timeo; } /************************************************************************ * Procedures which manipulate socket state flags, wakeups, etc. * ************************************************************************ * * Normal sequence from the active (originating) side is that * soisconnecting() is called during processing of connect() call, resulting * in an eventual call to soisconnected() if/when the connection is * established. When the connection is torn down soisdisconnecting() is * called during processing of disconnect() call, and soisdisconnected() is * called when the connection to the peer is totally severed. * * The semantics of these routines are such that connectionless protocols * can call soisconnected() and soisdisconnected() only, bypassing the * in-progress calls when setting up a ``connection'' takes no time. * * From the passive side, a socket is created with two queues of sockets: * so_incomp for connections in progress and so_comp for connections * already made and awaiting user acceptance. As a protocol is preparing * incoming connections, it creates a socket structure queued on so_incomp * by calling sonewconn(). When the connection is established, * soisconnected() is called, and transfers the socket structure to so_comp, * making it available to accept(). * * If a socket is closed with sockets on either so_incomp or so_comp, these * sockets are dropped. * * If higher level protocols are implemented in the kernel, the wakeups * done here will sometimes cause software-interrupt process scheduling. */ void soisconnecting(struct socket *so) { so->so_state &= ~(SS_ISCONNECTED|SS_ISDISCONNECTING); so->so_state |= SS_ISCONNECTING; } void soisconnected(struct socket *so) { struct socket *head = so->so_head; so->so_state &= ~(SS_ISCONNECTING|SS_ISDISCONNECTING|SS_ISCONFIRMING); so->so_state |= SS_ISCONNECTED; if (head && (so->so_state & SS_INCOMP)) { if ((so->so_options & SO_ACCEPTFILTER) != 0) { so->so_upcall = head->so_accf->so_accept_filter->accf_callback; so->so_upcallarg = head->so_accf->so_accept_filter_arg; so->so_rcv.ssb_flags |= SSB_UPCALL; so->so_options &= ~SO_ACCEPTFILTER; so->so_upcall(so, so->so_upcallarg, 0); return; } TAILQ_REMOVE(&head->so_incomp, so, so_list); head->so_incqlen--; so->so_state &= ~SS_INCOMP; TAILQ_INSERT_TAIL(&head->so_comp, so, so_list); head->so_qlen++; so->so_state |= SS_COMP; sorwakeup(head); wakeup_one(&head->so_timeo); } else { wakeup(&so->so_timeo); sorwakeup(so); sowwakeup(so); } } void soisdisconnecting(struct socket *so) { so->so_state &= ~SS_ISCONNECTING; so->so_state |= (SS_ISDISCONNECTING|SS_CANTRCVMORE|SS_CANTSENDMORE); wakeup((caddr_t)&so->so_timeo); sowwakeup(so); sorwakeup(so); } void soisdisconnected(struct socket *so) { so->so_state &= ~(SS_ISCONNECTING|SS_ISCONNECTED|SS_ISDISCONNECTING); so->so_state |= (SS_CANTRCVMORE|SS_CANTSENDMORE|SS_ISDISCONNECTED); wakeup((caddr_t)&so->so_timeo); sbdrop(&so->so_snd.sb, so->so_snd.ssb_cc); sowwakeup(so); sorwakeup(so); } /* * When an attempt at a new connection is noted on a socket * which accepts connections, sonewconn is called. If the * connection is possible (subject to space constraints, etc.) * then we allocate a new structure, propoerly linked into the * data structure of the original socket, and return this. * Connstatus may be 0, or SO_ISCONFIRMING, or SO_ISCONNECTED. */ struct socket * sonewconn(struct socket *head, int connstatus) { struct socket *so; struct pru_attach_info ai; if (head->so_qlen > 3 * head->so_qlimit / 2) return ((struct socket *)0); so = soalloc(1); if (so == NULL) return (NULL); if ((head->so_options & SO_ACCEPTFILTER) != 0) connstatus = 0; so->so_head = head; so->so_type = head->so_type; so->so_options = head->so_options &~ SO_ACCEPTCONN; so->so_linger = head->so_linger; so->so_state = head->so_state | SS_NOFDREF; so->so_proto = head->so_proto; so->so_timeo = head->so_timeo; so->so_cred = crhold(head->so_cred); ai.sb_rlimit = NULL; ai.p_ucred = NULL; ai.fd_rdir = NULL; /* jail code cruft XXX JH */ if (soreserve(so, head->so_snd.ssb_hiwat, head->so_rcv.ssb_hiwat, NULL) || /* Directly call function since we're already at protocol level. */ (*so->so_proto->pr_usrreqs->pru_attach)(so, 0, &ai)) { sodealloc(so); return ((struct socket *)0); } if (connstatus) { TAILQ_INSERT_TAIL(&head->so_comp, so, so_list); so->so_state |= SS_COMP; head->so_qlen++; } else { if (head->so_incqlen > head->so_qlimit) { struct socket *sp; sp = TAILQ_FIRST(&head->so_incomp); (void) soabort(sp); } TAILQ_INSERT_TAIL(&head->so_incomp, so, so_list); so->so_state |= SS_INCOMP; head->so_incqlen++; } if (connstatus) { sorwakeup(head); wakeup((caddr_t)&head->so_timeo); so->so_state |= connstatus; } return (so); } /* * Socantsendmore indicates that no more data will be sent on the * socket; it would normally be applied to a socket when the user * informs the system that no more data is to be sent, by the protocol * code (in case PRU_SHUTDOWN). Socantrcvmore indicates that no more data * will be received, and will normally be applied to the socket by a * protocol when it detects that the peer will send no more data. * Data queued for reading in the socket may yet be read. */ void socantsendmore(struct socket *so) { so->so_state |= SS_CANTSENDMORE; sowwakeup(so); } void socantrcvmore(struct socket *so) { so->so_state |= SS_CANTRCVMORE; sorwakeup(so); } /* * Wakeup processes waiting on a socket buffer. Do asynchronous notification * via SIGIO if the socket has the SS_ASYNC flag set. */ void sowakeup(struct socket *so, struct signalsockbuf *ssb) { struct selinfo *selinfo = &ssb->ssb_sel; selwakeup(selinfo); ssb->ssb_flags &= ~SSB_SEL; if (ssb->ssb_flags & SSB_WAIT) { ssb->ssb_flags &= ~SSB_WAIT; wakeup((caddr_t)&ssb->ssb_cc); } if ((so->so_state & SS_ASYNC) && so->so_sigio != NULL) pgsigio(so->so_sigio, SIGIO, 0); if (ssb->ssb_flags & SSB_UPCALL) (*so->so_upcall)(so, so->so_upcallarg, MB_DONTWAIT); if (ssb->ssb_flags & SSB_AIO) aio_swake(so, ssb); KNOTE(&selinfo->si_note, 0); if (ssb->ssb_flags & SSB_MEVENT) { struct netmsg_so_notify *msg, *nmsg; TAILQ_FOREACH_MUTABLE(msg, &selinfo->si_mlist, nm_list, nmsg) { if (msg->nm_predicate((struct netmsg *)msg)) { TAILQ_REMOVE(&selinfo->si_mlist, msg, nm_list); lwkt_replymsg(&msg->nm_lmsg, msg->nm_lmsg.ms_error); } } if (TAILQ_EMPTY(&ssb->ssb_sel.si_mlist)) ssb->ssb_flags &= ~SSB_MEVENT; } } /* * Socket buffer (struct signalsockbuf) utility routines. * * Each socket contains two socket buffers: one for sending data and * one for receiving data. Each buffer contains a queue of mbufs, * information about the number of mbufs and amount of data in the * queue, and other fields allowing select() statements and notification * on data availability to be implemented. * * Data stored in a socket buffer is maintained as a list of records. * Each record is a list of mbufs chained together with the m_next * field. Records are chained together with the m_nextpkt field. The upper * level routine soreceive() expects the following conventions to be * observed when placing information in the receive buffer: * * 1. If the protocol requires each message be preceded by the sender's * name, then a record containing that name must be present before * any associated data (mbuf's must be of type MT_SONAME). * 2. If the protocol supports the exchange of ``access rights'' (really * just additional data associated with the message), and there are * ``rights'' to be received, then a record containing this data * should be present (mbuf's must be of type MT_RIGHTS). * 3. If a name or rights record exists, then it must be followed by * a data record, perhaps of zero length. * * Before using a new socket structure it is first necessary to reserve * buffer space to the socket, by calling sbreserve(). This should commit * some of the available buffer space in the system buffer pool for the * socket (currently, it does nothing but enforce limits). The space * should be released by calling ssb_release() when the socket is destroyed. */ int soreserve(struct socket *so, u_long sndcc, u_long rcvcc, struct rlimit *rl) { if (ssb_reserve(&so->so_snd, sndcc, so, rl) == 0) goto bad; if (ssb_reserve(&so->so_rcv, rcvcc, so, rl) == 0) goto bad2; if (so->so_rcv.ssb_lowat == 0) so->so_rcv.ssb_lowat = 1; if (so->so_snd.ssb_lowat == 0) so->so_snd.ssb_lowat = MCLBYTES; if (so->so_snd.ssb_lowat > so->so_snd.ssb_hiwat) so->so_snd.ssb_lowat = so->so_snd.ssb_hiwat; return (0); bad2: ssb_release(&so->so_snd, so); bad: return (ENOBUFS); } static int sysctl_handle_sb_max(SYSCTL_HANDLER_ARGS) { int error = 0; u_long old_sb_max = sb_max; error = SYSCTL_OUT(req, arg1, sizeof(int)); if (error || !req->newptr) return (error); error = SYSCTL_IN(req, arg1, sizeof(int)); if (error) return (error); if (sb_max < MSIZE + MCLBYTES) { sb_max = old_sb_max; return (EINVAL); } sb_max_adj = (u_quad_t)sb_max * MCLBYTES / (MSIZE + MCLBYTES); return (0); } /* * Allot mbufs to a signalsockbuf. * Attempt to scale mbmax so that mbcnt doesn't become limiting * if buffering efficiency is near the normal case. */ int ssb_reserve(struct signalsockbuf *ssb, u_long cc, struct socket *so, struct rlimit *rl) { /* * rl will only be NULL when we're in an interrupt (eg, in tcp_input) * or when called from netgraph (ie, ngd_attach) */ if (cc > sb_max_adj) return (0); if (!chgsbsize(so->so_cred->cr_uidinfo, &ssb->ssb_hiwat, cc, rl ? rl->rlim_cur : RLIM_INFINITY)) { return (0); } ssb->ssb_mbmax = min(cc * sb_efficiency, sb_max); if (ssb->ssb_lowat > ssb->ssb_hiwat) ssb->ssb_lowat = ssb->ssb_hiwat; return (1); } /* * Free mbufs held by a socket, and reserved mbuf space. */ void ssb_release(struct signalsockbuf *ssb, struct socket *so) { sbflush(&ssb->sb); (void)chgsbsize(so->so_cred->cr_uidinfo, &ssb->ssb_hiwat, 0, RLIM_INFINITY); ssb->ssb_mbmax = 0; } /* * Some routines that return EOPNOTSUPP for entry points that are not * supported by a protocol. Fill in as needed. */ int pru_accept_notsupp(struct socket *so, struct sockaddr **nam) { return EOPNOTSUPP; } int pru_connect_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td) { return EOPNOTSUPP; } int pru_connect2_notsupp(struct socket *so1, struct socket *so2) { return EOPNOTSUPP; } int pru_control_notsupp(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp, struct thread *td) { return EOPNOTSUPP; } int pru_listen_notsupp(struct socket *so, struct thread *td) { return EOPNOTSUPP; } int pru_rcvd_notsupp(struct socket *so, int flags) { return EOPNOTSUPP; } int pru_rcvoob_notsupp(struct socket *so, struct mbuf *m, int flags) { return EOPNOTSUPP; } /* * This isn't really a ``null'' operation, but it's the default one * and doesn't do anything destructive. */ int pru_sense_null(struct socket *so, struct stat *sb) { sb->st_blksize = so->so_snd.ssb_hiwat; return 0; } /* * Make a copy of a sockaddr in a malloced buffer of type M_SONAME. Callers * of this routine assume that it always succeeds, so we have to use a * blockable allocation even though we might be called from a critical thread. */ struct sockaddr * dup_sockaddr(const struct sockaddr *sa) { struct sockaddr *sa2; sa2 = kmalloc(sa->sa_len, M_SONAME, M_INTWAIT); bcopy(sa, sa2, sa->sa_len); return (sa2); } /* * Create an external-format (``xsocket'') structure using the information * in the kernel-format socket structure pointed to by so. This is done * to reduce the spew of irrelevant information over this interface, * to isolate user code from changes in the kernel structure, and * potentially to provide information-hiding if we decide that * some of this information should be hidden from users. */ void sotoxsocket(struct socket *so, struct xsocket *xso) { xso->xso_len = sizeof *xso; xso->xso_so = so; xso->so_type = so->so_type; xso->so_options = so->so_options; xso->so_linger = so->so_linger; xso->so_state = so->so_state; xso->so_pcb = so->so_pcb; xso->xso_protocol = so->so_proto->pr_protocol; xso->xso_family = so->so_proto->pr_domain->dom_family; xso->so_qlen = so->so_qlen; xso->so_incqlen = so->so_incqlen; xso->so_qlimit = so->so_qlimit; xso->so_timeo = so->so_timeo; xso->so_error = so->so_error; xso->so_pgid = so->so_sigio ? so->so_sigio->sio_pgid : 0; xso->so_oobmark = so->so_oobmark; ssbtoxsockbuf(&so->so_snd, &xso->so_snd); ssbtoxsockbuf(&so->so_rcv, &xso->so_rcv); xso->so_uid = so->so_cred->cr_uid; } /* * Here is the definition of some of the basic objects in the kern.ipc * branch of the MIB. */ SYSCTL_NODE(_kern, KERN_IPC, ipc, CTLFLAG_RW, 0, "IPC"); /* This takes the place of kern.maxsockbuf, which moved to kern.ipc. */ static int dummy; SYSCTL_INT(_kern, KERN_DUMMY, dummy, CTLFLAG_RW, &dummy, 0, ""); SYSCTL_OID(_kern_ipc, KIPC_MAXSOCKBUF, maxsockbuf, CTLTYPE_INT|CTLFLAG_RW, &sb_max, 0, sysctl_handle_sb_max, "I", "Maximum socket buffer size"); SYSCTL_INT(_kern_ipc, OID_AUTO, maxsockets, CTLFLAG_RD, &maxsockets, 0, "Maximum number of sockets avaliable"); SYSCTL_INT(_kern_ipc, KIPC_SOCKBUF_WASTE, sockbuf_waste_factor, CTLFLAG_RW, &sb_efficiency, 0, ""); /* * Initialize maxsockets */ static void init_maxsockets(void *ignored) { TUNABLE_INT_FETCH("kern.ipc.maxsockets", &maxsockets); maxsockets = imax(maxsockets, imax(maxfiles, nmbclusters)); } SYSINIT(param, SI_BOOT1_TUNABLES, SI_ORDER_ANY, init_maxsockets, NULL);