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1// SPDX-License-Identifier: GPL-2.02// tcp_MAX_SKB_FRAGS test3//4// Verify that sending an iovec of tcp_MAX_SKB_FRAGS + 1 elements will5// 1) fit in a single packet without zerocopy6// 2) spill over into a second packet with zerocopy,7// because each iovec element becomes a frag8// 3) the PSH bit is set on an skb when it runs out of fragments9 10`./defaults.sh`11 12 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 313 +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 014 +0 setsockopt(3, SOL_SOCKET, SO_ZEROCOPY, [1], 4) = 015 16 // Each pinned zerocopy page is fully accounted to skb->truesize.17 // This test generates a worst case packet with each frag storing18 // one byte, but increasing truesize with a page (64KB on PPC).19 +0 setsockopt(3, SOL_SOCKET, SO_SNDBUF, [2000000], 4) = 020 21 +0 bind(3, ..., ...) = 022 +0 listen(3, 1) = 023 24 +0 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7>25 +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>26 +0 < . 1:1(0) ack 1 win 25727 28 +0 accept(3, ..., ...) = 429 30 // send an iov of 18 elements: just becomes a linear skb31 +0 sendmsg(4, {msg_name(...)=...,32 msg_iov(18)=[{..., 1}, {..., 1}, {..., 1}, {..., 1},33 {..., 1}, {..., 1}, {..., 1}, {..., 1},34 {..., 1}, {..., 1}, {..., 1}, {..., 1},35 {..., 1}, {..., 1}, {..., 1}, {..., 1},36 {..., 1}, {..., 1}],37 msg_flags=0}, 0) = 1838 39 +0 > P. 1:19(18) ack 140 +0 < . 1:1(0) ack 19 win 25741 42 // send a zerocopy iov of 18 elements:43 +1 sendmsg(4, {msg_name(...)=...,44 msg_iov(18)=[{..., 1}, {..., 1}, {..., 1}, {..., 1},45 {..., 1}, {..., 1}, {..., 1}, {..., 1},46 {..., 1}, {..., 1}, {..., 1}, {..., 1},47 {..., 1}, {..., 1}, {..., 1}, {..., 1},48 {..., 1}, {..., 1}],49 msg_flags=0}, MSG_ZEROCOPY) = 1850 51 // verify that it is split in one skb of 17 frags + 1 of 1 frag52 // verify that both have the PSH bit set53 +0 > P. 19:36(17) ack 154 +0 < . 1:1(0) ack 36 win 25755 56 +0 > P. 36:37(1) ack 157 +0 < . 1:1(0) ack 37 win 25758 59 +1 recvmsg(4, {msg_name(...)=...,60 msg_iov(1)=[{...,0}],61 msg_flags=MSG_ERRQUEUE,62 msg_control=[63 {cmsg_level=CMSG_LEVEL_IP,64 cmsg_type=CMSG_TYPE_RECVERR,65 cmsg_data={ee_errno=0,66 ee_origin=SO_EE_ORIGIN_ZEROCOPY,67 ee_type=0,68 ee_code=SO_EE_CODE_ZEROCOPY_COPIED,69 ee_info=0,70 ee_data=0}}71 ]}, MSG_ERRQUEUE) = 072 73 // send a zerocopy iov of 64 elements:74 +0 sendmsg(4, {msg_name(...)=...,75 msg_iov(64)=[{..., 1}, {..., 1}, {..., 1}, {..., 1},76 {..., 1}, {..., 1}, {..., 1}, {..., 1},77 {..., 1}, {..., 1}, {..., 1}, {..., 1},78 {..., 1}, {..., 1}, {..., 1}, {..., 1},79 {..., 1}, {..., 1}, {..., 1}, {..., 1},80 {..., 1}, {..., 1}, {..., 1}, {..., 1},81 {..., 1}, {..., 1}, {..., 1}, {..., 1},82 {..., 1}, {..., 1}, {..., 1}, {..., 1},83 {..., 1}, {..., 1}, {..., 1}, {..., 1},84 {..., 1}, {..., 1}, {..., 1}, {..., 1},85 {..., 1}, {..., 1}, {..., 1}, {..., 1},86 {..., 1}, {..., 1}, {..., 1}, {..., 1},87 {..., 1}, {..., 1}, {..., 1}, {..., 1},88 {..., 1}, {..., 1}, {..., 1}, {..., 1},89 {..., 1}, {..., 1}, {..., 1}, {..., 1},90 {..., 1}, {..., 1}, {..., 1}, {..., 1}],91 msg_flags=0}, MSG_ZEROCOPY) = 6492 93 // verify that it is split in skbs with 17 frags94 +0 > P. 37:54(17) ack 195 +0 < . 1:1(0) ack 54 win 25796 97 +0 > P. 54:71(17) ack 198 +0 < . 1:1(0) ack 71 win 25799 100 +0 > P. 71:88(17) ack 1101 +0 < . 1:1(0) ack 88 win 257102 103 +0 > P. 88:101(13) ack 1104 +0 < . 1:1(0) ack 101 win 257105 106 +1 recvmsg(4, {msg_name(...)=...,107 msg_iov(1)=[{...,0}],108 msg_flags=MSG_ERRQUEUE,109 msg_control=[110 {cmsg_level=CMSG_LEVEL_IP,111 cmsg_type=CMSG_TYPE_RECVERR,112 cmsg_data={ee_errno=0,113 ee_origin=SO_EE_ORIGIN_ZEROCOPY,114 ee_type=0,115 ee_code=SO_EE_CODE_ZEROCOPY_COPIED,116 ee_info=1,117 ee_data=1}}118 ]}, MSG_ERRQUEUE) = 0119