Date: Sun, 27 Apr 2014 17:41:18 +0000 (UTC) From: "Alexander V. Chernikov" <melifaro@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r265019 - head/sys/net Message-ID: <201404271741.s3RHfIYF058370@svn.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: melifaro Date: Sun Apr 27 17:41:18 2014 New Revision: 265019 URL: http://svnweb.freebsd.org/changeset/base/265019 Log: Improve memory allocation model for rt_msg2() rtsock messages: * memory is now allocated as early as possible, without holding locks. * sysctl users are now guaranteed to get a response (M_WAITOK buffer prealloc). * socket users are more likely to use on-stack buffer for replies. * standard kernel malloc/free functions are now used instead of radix wrappers. rt_msg2() has been renamed to rtsock_msg_buffer(). MFC after: 1 month Modified: head/sys/net/rtsock.c Modified: head/sys/net/rtsock.c ============================================================================== --- head/sys/net/rtsock.c Sun Apr 27 16:40:40 2014 (r265018) +++ head/sys/net/rtsock.c Sun Apr 27 17:41:18 2014 (r265019) @@ -152,8 +152,8 @@ struct walkarg { static void rts_input(struct mbuf *m); static struct mbuf *rt_msg1(int type, struct rt_addrinfo *rtinfo); -static int rt_msg2(int type, struct rt_addrinfo *rtinfo, - caddr_t cp, struct walkarg *w); +static int rtsock_msg_buffer(int type, struct rt_addrinfo *rtinfo, + struct walkarg *w, int *plen); static int rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo); static int sysctl_dumpentry(struct radix_node *rn, void *vw); @@ -526,11 +526,13 @@ route_output(struct mbuf *m, struct sock struct sockaddr_in6 *sin6; int i, rti_need_deembed = 0; #endif - int len, error = 0, fibnum; + int alloc_len = 0, len, error = 0, fibnum; struct ifnet *ifp = NULL; union sockaddr_union saun; sa_family_t saf = AF_UNSPEC; struct rawcb *rp = NULL; + struct walkarg w; + char msgbuf[512]; fibnum = so->so_fibnum; @@ -545,15 +547,31 @@ route_output(struct mbuf *m, struct sock len != mtod(m, struct rt_msghdr *)->rtm_msglen) senderr(EINVAL); - R_Malloc(rtm, struct rt_msghdr *, len); - if (rtm == NULL) - senderr(ENOBUFS); + /* + * Most of current messages are in range 200-240 bytes, + * minimize possible failures by using on-stack buffer + * which should fit for most messages. + * However, use stable memory if we need to handle + * something large. + */ + if (len < sizeof(msgbuf)) { + alloc_len = sizeof(msgbuf); + rtm = (struct rt_msghdr *)msgbuf; + } else { + alloc_len = roundup2(len, 1024); + rtm = malloc(alloc_len, M_TEMP, M_NOWAIT); + if (rtm == NULL) + senderr(ENOBUFS); + } + m_copydata(m, 0, len, (caddr_t)rtm); bzero(&info, sizeof(info)); + bzero(&w, sizeof(w)); if (rtm->rtm_version != RTM_VERSION) { /* Do not touch message since format is unknown */ - Free(rtm); + if ((char *)rtm != msgbuf) + free(rtm, M_TEMP); rtm = NULL; senderr(EPROTONOSUPPORT); } @@ -798,18 +816,26 @@ report: } else if ((ifp = rt->rt_ifp) != NULL) { rtm->rtm_index = ifp->if_index; } - len = rt_msg2(rtm->rtm_type, &info, NULL, NULL); - if (len > rtm->rtm_msglen) { + + /* Check if we need to realloc storage */ + rtsock_msg_buffer(rtm->rtm_type, &info, NULL, &len); + if (len > alloc_len) { struct rt_msghdr *new_rtm; - R_Malloc(new_rtm, struct rt_msghdr *, len); + new_rtm = malloc(len, M_TEMP, M_NOWAIT); if (new_rtm == NULL) { RT_UNLOCK(rt); senderr(ENOBUFS); } bcopy(rtm, new_rtm, rtm->rtm_msglen); - Free(rtm); rtm = new_rtm; + free(rtm, M_TEMP); + rtm = new_rtm; + alloc_len = len; } - (void)rt_msg2(rtm->rtm_type, &info, (caddr_t)rtm, NULL); + + w.w_tmem = (caddr_t)rtm; + w.w_tmemsize = alloc_len; + rtsock_msg_buffer(rtm->rtm_type, &info, &w, &len); + if (rt->rt_flags & RTF_GWFLAG_COMPAT) rtm->rtm_flags = RTF_GATEWAY | (rt->rt_flags & ~RTF_GWFLAG_COMPAT); @@ -833,8 +859,8 @@ flush: */ if ((so->so_options & SO_USELOOPBACK) == 0) { if (V_route_cb.any_count <= 1) { - if (rtm != NULL) - Free(rtm); + if (rtm != NULL && (char *)rtm != msgbuf) + free(rtm, M_TEMP); m_freem(m); return (error); } @@ -870,7 +896,9 @@ flush: m = NULL; } else if (m->m_pkthdr.len > rtm->rtm_msglen) m_adj(m, rtm->rtm_msglen - m->m_pkthdr.len); - Free(rtm); + + if ((char *)rtm != msgbuf) + free(rtm, M_TEMP); } if (m != NULL) { M_SETFIB(m, fibnum); @@ -1041,21 +1069,26 @@ rt_msg1(int type, struct rt_addrinfo *rt } /* - * Used by the sysctl code and routing socket. + * Writes information related to @rtinfo object to preallocated buffer. + * Stores needed size in @plen. If @w is NULL, calculates size without + * writing. + * Used for sysctl dumps and rtsock answers (RTM_DEL/RTM_GET) generation. + * + * Returns 0 on success. + * */ static int -rt_msg2(int type, struct rt_addrinfo *rtinfo, caddr_t cp, struct walkarg *w) +rtsock_msg_buffer(int type, struct rt_addrinfo *rtinfo, struct walkarg *w, int *plen) { int i; - int len, dlen, second_time = 0; - caddr_t cp0; + int len, buflen = 0, dlen; + caddr_t cp; + struct rt_msghdr *rtm = NULL; #ifdef INET6 struct sockaddr_storage ss; struct sockaddr_in6 *sin6; #endif - rtinfo->rti_addrs = 0; -again: switch (type) { case RTM_DELADDR: @@ -1094,9 +1127,14 @@ again: default: len = sizeof(struct rt_msghdr); } - cp0 = cp; - if (cp0) - cp += len; + + if (w != NULL) { + rtm = (struct rt_msghdr *)w->w_tmem; + buflen = w->w_tmemsize - len; + cp = (caddr_t)w->w_tmem + len; + } + + rtinfo->rti_addrs = 0; for (i = 0; i < RTAX_MAX; i++) { struct sockaddr *sa; @@ -1104,7 +1142,7 @@ again: continue; rtinfo->rti_addrs |= (1 << i); dlen = SA_SIZE(sa); - if (cp) { + if (cp != NULL && buflen >= dlen) { #ifdef INET6 if (V_deembed_scopeid && sa->sa_family == AF_INET6) { sin6 = (struct sockaddr_in6 *)&ss; @@ -1115,37 +1153,40 @@ again: #endif bcopy((caddr_t)sa, cp, (unsigned)dlen); cp += dlen; + buflen -= dlen; + } else if (cp != NULL) { + /* + * Buffer too small. Count needed size + * and return with error. + */ + cp = NULL; } + len += dlen; } - len = ALIGN(len); - if (cp == NULL && w != NULL && !second_time) { - struct walkarg *rw = w; - if (rw->w_req) { - if (rw->w_tmemsize < len) { - if (rw->w_tmem) - free(rw->w_tmem, M_RTABLE); - rw->w_tmem = (caddr_t) - malloc(len, M_RTABLE, M_NOWAIT); - if (rw->w_tmem) - rw->w_tmemsize = len; - } - if (rw->w_tmem) { - cp = rw->w_tmem; - second_time = 1; - goto again; - } - } + if (cp != NULL) { + dlen = ALIGN(len) - len; + if (buflen < dlen) + cp = NULL; + else + buflen -= dlen; } - if (cp) { - struct rt_msghdr *rtm = (struct rt_msghdr *)cp0; + len = ALIGN(len); + if (cp != NULL) { + /* fill header iff buffer is large enough */ rtm->rtm_version = RTM_VERSION; rtm->rtm_type = type; rtm->rtm_msglen = len; } - return (len); + + *plen = len; + + if (w != NULL && cp == NULL) + return (ENOBUFS); + + return (0); } /* @@ -1473,7 +1514,8 @@ sysctl_dumpentry(struct radix_node *rn, if (rt->rt_ifp->if_flags & IFF_POINTOPOINT) info.rti_info[RTAX_BRD] = rt->rt_ifa->ifa_dstaddr; } - size = rt_msg2(RTM_GET, &info, NULL, w); + if ((error = rtsock_msg_buffer(RTM_GET, &info, w, &size)) != 0) + return (error); if (w->w_req && w->w_tmem) { struct rt_msghdr *rtm = (struct rt_msghdr *)w->w_tmem; @@ -1649,7 +1691,9 @@ sysctl_iflist(int af, struct walkarg *w) IF_ADDR_RLOCK(ifp); ifa = ifp->if_addr; info.rti_info[RTAX_IFP] = ifa->ifa_addr; - len = rt_msg2(RTM_IFINFO, &info, NULL, w); + error = rtsock_msg_buffer(RTM_IFINFO, &info, w, &len); + if (error != 0) + goto done; info.rti_info[RTAX_IFP] = NULL; if (w->w_req && w->w_tmem) { if (w->w_op == NET_RT_IFLISTL) @@ -1668,7 +1712,9 @@ sysctl_iflist(int af, struct walkarg *w) info.rti_info[RTAX_IFA] = ifa->ifa_addr; info.rti_info[RTAX_NETMASK] = ifa->ifa_netmask; info.rti_info[RTAX_BRD] = ifa->ifa_dstaddr; - len = rt_msg2(RTM_NEWADDR, &info, NULL, w); + error = rtsock_msg_buffer(RTM_NEWADDR, &info, w, &len); + if (error != 0) + goto done; if (w->w_req && w->w_tmem) { if (w->w_op == NET_RT_IFLISTL) error = sysctl_iflist_ifaml(ifa, &info, @@ -1718,7 +1764,9 @@ sysctl_ifmalist(int af, struct walkarg * info.rti_info[RTAX_GATEWAY] = (ifma->ifma_addr->sa_family != AF_LINK) ? ifma->ifma_lladdr : NULL; - len = rt_msg2(RTM_NEWMADDR, &info, NULL, w); + error = rtsock_msg_buffer(RTM_NEWADDR, &info, w, &len); + if (error != 0) + goto done; if (w->w_req && w->w_tmem) { struct ifma_msghdr *ifmam; @@ -1778,6 +1826,14 @@ sysctl_rtsock(SYSCTL_HANDLER_ARGS) error = sysctl_wire_old_buffer(req, 0); if (error) return (error); + + /* + * Allocate reply buffer in advance. + * All rtsock messages has maximum length of u_short. + */ + w.w_tmemsize = 65536; + w.w_tmem = malloc(w.w_tmemsize, M_TEMP, M_WAITOK); + switch (w.w_op) { case NET_RT_DUMP: @@ -1824,8 +1880,8 @@ sysctl_rtsock(SYSCTL_HANDLER_ARGS) error = sysctl_ifmalist(af, &w); break; } - if (w.w_tmem) - free(w.w_tmem, M_RTABLE); + + free(w.w_tmem, M_TEMP); return (error); }
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201404271741.s3RHfIYF058370>