Date: Mon, 3 Jun 2013 12:55:13 +0000 (UTC) From: Andre Oppermann <andre@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r251296 - in head/sys: net netinet Message-ID: <201306031255.r53CtDYw089624@svn.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: andre Date: Mon Jun 3 12:55:13 2013 New Revision: 251296 URL: http://svnweb.freebsd.org/changeset/base/251296 Log: Allow drivers to specify a maximum TSO length in bytes if they are limited in the amount of data they can handle at once. Drivers can set ifp->if_hw_tsomax before calling ether_ifattach() to change the limit. The lowest allowable size is IP_MAXPACKET / 8 (8192 bytes) as anything less wouldn't be very useful anymore. The upper limit is still at IP_MAXPACKET (65536 bytes). Raising it requires further auditing of the IPv4/v6 code path's as the length field in the IP header would overflow leading to confusion in firewalls and others packet handler on the real size of the packet. The placement into "struct ifnet" is a bit hackish but the best place that was found. When the stack/driver boundary is updated it should be handled in a better way. Submitted by: cperciva (earlier version) Reviewed by: cperciva Tested by: cperciva MFC after: 1 week (using spare struct members to preserve ABI) Modified: head/sys/net/if.c head/sys/net/if_var.h head/sys/netinet/tcp_input.c head/sys/netinet/tcp_output.c head/sys/netinet/tcp_subr.c head/sys/netinet/tcp_var.h Modified: head/sys/net/if.c ============================================================================== --- head/sys/net/if.c Mon Jun 3 12:43:09 2013 (r251295) +++ head/sys/net/if.c Mon Jun 3 12:55:13 2013 (r251296) @@ -74,18 +74,18 @@ #include <net/vnet.h> #if defined(INET) || defined(INET6) -/*XXX*/ #include <netinet/in.h> #include <netinet/in_var.h> +#include <netinet/ip.h> #include <netinet/ip_carp.h> +#ifdef INET +#include <netinet/if_ether.h> +#endif /* INET */ #ifdef INET6 #include <netinet6/in6_var.h> #include <netinet6/in6_ifattach.h> -#endif -#endif -#ifdef INET -#include <netinet/if_ether.h> -#endif +#endif /* INET6 */ +#endif /* INET || INET6 */ #include <security/mac/mac_framework.h> @@ -653,6 +653,13 @@ if_attach_internal(struct ifnet *ifp, in TAILQ_INSERT_HEAD(&ifp->if_addrhead, ifa, ifa_link); /* Reliably crash if used uninitialized. */ ifp->if_broadcastaddr = NULL; + + /* Initialize to max value. */ + if (ifp->if_hw_tsomax == 0) + ifp->if_hw_tsomax = IP_MAXPACKET; + KASSERT(ifp->if_hw_tsomax <= IP_MAXPACKET && + ifp->if_hw_tsomax >= IP_MAXPACKET / 8, + ("%s: tsomax outside of range", __func__)); } #ifdef VIMAGE else { Modified: head/sys/net/if_var.h ============================================================================== --- head/sys/net/if_var.h Mon Jun 3 12:43:09 2013 (r251295) +++ head/sys/net/if_var.h Mon Jun 3 12:55:13 2013 (r251296) @@ -204,6 +204,11 @@ struct ifnet { u_int if_fib; /* interface FIB */ u_char if_alloctype; /* if_type at time of allocation */ + u_int if_hw_tsomax; /* tso burst length limit, the minmum + * is (IP_MAXPACKET / 8). + * XXXAO: Have to find a better place + * for it eventually. */ + /* * Spare fields are added so that we can modify sensitive data * structures without changing the kernel binary interface, and must Modified: head/sys/netinet/tcp_input.c ============================================================================== --- head/sys/netinet/tcp_input.c Mon Jun 3 12:43:09 2013 (r251295) +++ head/sys/netinet/tcp_input.c Mon Jun 3 12:55:13 2013 (r251296) @@ -3434,7 +3434,7 @@ tcp_xmit_timer(struct tcpcb *tp, int rtt */ void tcp_mss_update(struct tcpcb *tp, int offer, int mtuoffer, - struct hc_metrics_lite *metricptr, int *mtuflags) + struct hc_metrics_lite *metricptr, struct tcp_ifcap *cap) { int mss = 0; u_long maxmtu = 0; @@ -3461,7 +3461,7 @@ tcp_mss_update(struct tcpcb *tp, int off /* Initialize. */ #ifdef INET6 if (isipv6) { - maxmtu = tcp_maxmtu6(&inp->inp_inc, mtuflags); + maxmtu = tcp_maxmtu6(&inp->inp_inc, cap); tp->t_maxopd = tp->t_maxseg = V_tcp_v6mssdflt; } #endif @@ -3470,7 +3470,7 @@ tcp_mss_update(struct tcpcb *tp, int off #endif #ifdef INET { - maxmtu = tcp_maxmtu(&inp->inp_inc, mtuflags); + maxmtu = tcp_maxmtu(&inp->inp_inc, cap); tp->t_maxopd = tp->t_maxseg = V_tcp_mssdflt; } #endif @@ -3605,11 +3605,12 @@ tcp_mss(struct tcpcb *tp, int offer) struct inpcb *inp; struct socket *so; struct hc_metrics_lite metrics; - int mtuflags = 0; + struct tcp_ifcap cap; KASSERT(tp != NULL, ("%s: tp == NULL", __func__)); - - tcp_mss_update(tp, offer, -1, &metrics, &mtuflags); + + bzero(&cap, sizeof(cap)); + tcp_mss_update(tp, offer, -1, &metrics, &cap); mss = tp->t_maxseg; inp = tp->t_inpcb; @@ -3654,8 +3655,10 @@ tcp_mss(struct tcpcb *tp, int offer) SOCKBUF_UNLOCK(&so->so_rcv); /* Check the interface for TSO capabilities. */ - if (mtuflags & CSUM_TSO) + if (cap.ifcap & CSUM_TSO) { tp->t_flags |= TF_TSO; + tp->t_tsomax = cap.tsomax; + } } /* Modified: head/sys/netinet/tcp_output.c ============================================================================== --- head/sys/netinet/tcp_output.c Mon Jun 3 12:43:09 2013 (r251295) +++ head/sys/netinet/tcp_output.c Mon Jun 3 12:55:13 2013 (r251296) @@ -769,12 +769,13 @@ send: ("%s: TSO can't do IP options", __func__)); /* - * Limit a burst to IP_MAXPACKET minus IP, + * Limit a burst to t_tsomax minus IP, * TCP and options length to keep ip->ip_len - * from overflowing. + * from overflowing or exceeding the maximum + * length allowed by the network interface. */ - if (len > IP_MAXPACKET - hdrlen) { - len = IP_MAXPACKET - hdrlen; + if (len > tp->t_tsomax - hdrlen) { + len = tp->t_tsomax - hdrlen; sendalot = 1; } Modified: head/sys/netinet/tcp_subr.c ============================================================================== --- head/sys/netinet/tcp_subr.c Mon Jun 3 12:43:09 2013 (r251295) +++ head/sys/netinet/tcp_subr.c Mon Jun 3 12:55:13 2013 (r251296) @@ -1770,7 +1770,7 @@ tcp_mtudisc(struct inpcb *inp, int mtuof * tcp_mss_update to get the peer/interface MTU. */ u_long -tcp_maxmtu(struct in_conninfo *inc, int *flags) +tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap) { struct route sro; struct sockaddr_in *dst; @@ -1795,10 +1795,11 @@ tcp_maxmtu(struct in_conninfo *inc, int maxmtu = min(sro.ro_rt->rt_rmx.rmx_mtu, ifp->if_mtu); /* Report additional interface capabilities. */ - if (flags != NULL) { + if (cap != NULL) { if (ifp->if_capenable & IFCAP_TSO4 && ifp->if_hwassist & CSUM_TSO) - *flags |= CSUM_TSO; + cap->ifcap |= CSUM_TSO; + cap->tsomax = ifp->if_hw_tsomax; } RTFREE(sro.ro_rt); } @@ -1808,7 +1809,7 @@ tcp_maxmtu(struct in_conninfo *inc, int #ifdef INET6 u_long -tcp_maxmtu6(struct in_conninfo *inc, int *flags) +tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap) { struct route_in6 sro6; struct ifnet *ifp; @@ -1832,10 +1833,11 @@ tcp_maxmtu6(struct in_conninfo *inc, int IN6_LINKMTU(sro6.ro_rt->rt_ifp)); /* Report additional interface capabilities. */ - if (flags != NULL) { + if (cap != NULL) { if (ifp->if_capenable & IFCAP_TSO6 && ifp->if_hwassist & CSUM_TSO) - *flags |= CSUM_TSO; + cap->ifcap |= CSUM_TSO; + cap->tsomax = ifp->if_hw_tsomax; } RTFREE(sro6.ro_rt); } Modified: head/sys/netinet/tcp_var.h ============================================================================== --- head/sys/netinet/tcp_var.h Mon Jun 3 12:43:09 2013 (r251295) +++ head/sys/netinet/tcp_var.h Mon Jun 3 12:55:13 2013 (r251296) @@ -208,6 +208,8 @@ struct tcpcb { u_int t_keepintvl; /* interval between keepalives */ u_int t_keepcnt; /* number of keepalives before close */ + u_int t_tsomax; /* tso burst length limit */ + uint32_t t_ispare[8]; /* 5 UTO, 3 TBD */ void *t_pspare2[4]; /* 4 TBD */ uint64_t _pad[6]; /* 6 TBD (1-2 CC/RTT?) */ @@ -324,6 +326,15 @@ struct hc_metrics_lite { /* must stay in u_long rmx_recvpipe; /* inbound delay-bandwidth product */ }; +/* + * Used by tcp_maxmtu() to communicate interface specific features + * and limits at the time of connection setup. + */ +struct tcp_ifcap { + int ifcap; + u_int tsomax; +}; + #ifndef _NETINET_IN_PCB_H_ struct in_conninfo; #endif /* _NETINET_IN_PCB_H_ */ @@ -782,10 +793,10 @@ void tcp_reass_flush(struct tcpcb *); void tcp_reass_destroy(void); #endif void tcp_input(struct mbuf *, int); -u_long tcp_maxmtu(struct in_conninfo *, int *); -u_long tcp_maxmtu6(struct in_conninfo *, int *); +u_long tcp_maxmtu(struct in_conninfo *, struct tcp_ifcap *); +u_long tcp_maxmtu6(struct in_conninfo *, struct tcp_ifcap *); void tcp_mss_update(struct tcpcb *, int, int, struct hc_metrics_lite *, - int *); + struct tcp_ifcap *); void tcp_mss(struct tcpcb *, int); int tcp_mssopt(struct in_conninfo *); struct inpcb *
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201306031255.r53CtDYw089624>