xnu-2050.18.24.tar.gz

[apple/xnu.git] / bsd / netinet / tcp_output.c

diff --git a/bsd/netinet/tcp_output.c b/bsd/netinet/tcp_output.c
index 8a9eeb9cf07bf4a5ca08dc405f66ce1dcde8a745..83a205319e79b9cc92ef47eafecf7e7e2b0e6b3e 100644 (file)
--- a/bsd/netinet/tcp_output.c
+++ b/bsd/netinet/tcp_output.c
@@ -299,7 +299,7 @@ tcp_output(struct tcpcb *tp)
        u_int16_t       socket_id = get_socket_id(so);
        int so_options = so->so_options;
        struct rtentry *rt;
-       u_int32_t basertt, svc_flags = 0;
+       u_int32_t basertt, svc_flags = 0, allocated_len;
        u_int32_t lro_ackmore = (tp->t_lropktlen != 0) ? 1 : 0;
        struct mbuf *mnext = NULL;
        int sackoptlen = 0;
@@ -825,7 +825,10 @@ after_sack_rexmit:
                        goto send;
                }
                if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
-                       tp->t_flags &= ~TF_MAXSEGSNT;
+                       if (len >= tp->t_maxseg)
+                               tp->t_flags |= TF_MAXSEGSNT;
+                       else
+                               tp->t_flags &= ~TF_MAXSEGSNT;
                        goto send;
                }
                if (sack_rxmit)
@@ -1275,15 +1278,8 @@ send:
                }
        }
 
-/*#ifdef DIAGNOSTIC*/
-#if INET6
        if (max_linkhdr + hdrlen > MCLBYTES)
                panic("tcphdr too big");
-#else
-       if (max_linkhdr + hdrlen > MHLEN)
-               panic("tcphdr too big");
-#endif
-/*#endif*/
 
        /* Check if there is enough data in the send socket
         * buffer to start measuring bw 
@@ -1314,7 +1310,8 @@ send:
                        tcpstat.tcps_sndrexmitpack++;
                        tcpstat.tcps_sndrexmitbyte += len;
                        if (nstat_collect) {
-                               nstat_route_tx(tp->t_inpcb->inp_route.ro_rt, 1, len, NSTAT_TX_FLAG_RETRANSMIT);
+                               nstat_route_tx(tp->t_inpcb->inp_route.ro_rt, 1, 
+                                       len, NSTAT_TX_FLAG_RETRANSMIT);
                                locked_add_64(&tp->t_inpcb->inp_stat->txpackets, 1);
                                locked_add_64(&tp->t_inpcb->inp_stat->txbytes, len);
                                tp->t_stat.txretransmitbytes += len;
@@ -1327,18 +1324,6 @@ send:
                                locked_add_64(&tp->t_inpcb->inp_stat->txbytes, len);
                        }
                }
-#ifdef notyet
-               if ((m = m_copypack(so->so_snd.sb_mb, off,
-                   (int)len, max_linkhdr + hdrlen)) == 0) {
-                       error = ENOBUFS;
-                       goto out;
-               }
-               /*
-                * m_copypack left space for our hdr; use it.
-                */
-               m->m_len += hdrlen;
-               m->m_data -= hdrlen;
-#else
                /*
                 * try to use the new interface that allocates all 
                 * the necessary mbuf hdrs under 1 mbuf lock and 
@@ -1352,11 +1337,13 @@ send:
                 * data area (no cluster attached)
                 */
                m = NULL;
-#if INET6
+
+               /* minimum length we are going to allocate */
+               allocated_len = MHLEN;
                if (MHLEN < hdrlen + max_linkhdr) {
-                       MGETHDR(m, M_DONTWAIT, MT_HEADER);      /* MAC-OK */
+                       MGETHDR(m, M_DONTWAIT, MT_HEADER);
                        if (m == NULL) {
-                               error = ENOBUFS;
+                               error = ENOBUFS;
                                goto out;
                        }
                        MCLGET(m, M_DONTWAIT);
@@ -1367,13 +1354,14 @@ send:
                        }
                        m->m_data += max_linkhdr;
                        m->m_len = hdrlen;
+                       allocated_len = MCLBYTES;
                }
-#endif
-               if (len <= MHLEN - hdrlen - max_linkhdr) {
+               if (len <= allocated_len - hdrlen - max_linkhdr) {
                        if (m == NULL) {
-                               MGETHDR(m, M_DONTWAIT, MT_HEADER);      /* MAC-OK */
+                               VERIFY(allocated_len <= MHLEN);
+                               MGETHDR(m, M_DONTWAIT, MT_HEADER);
                                if (m == NULL) {
-                                       error = ENOBUFS;
+                                       error = ENOBUFS;
                                        goto out;
                                }
                                m->m_data += max_linkhdr;
@@ -1430,7 +1418,6 @@ send:
                                m->m_len = hdrlen;
                        }
                }
-#endif
                /*
                 * If we're sending everything we've got, set PUSH.
                 * (This will keep happy those implementations which only
@@ -1454,13 +1441,15 @@ send:
                        error = ENOBUFS;
                        goto out;
                }
-#if INET6
-               if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
-                   MHLEN >= hdrlen) {
-                       MH_ALIGN(m, hdrlen);
-               } else
-#endif
-                       m->m_data += max_linkhdr;
+               if (MHLEN < (hdrlen + max_linkhdr)) {
+                       MCLGET(m, M_DONTWAIT);
+                       if ((m->m_flags & M_EXT) == 0) {
+                               m_freem(m);
+                               error = ENOBUFS;
+                               goto out;
+                       }
+               }
+               m->m_data += max_linkhdr;
                m->m_len = hdrlen;
        }
        m->m_pkthdr.rcvif = 0;