From a0bd27053db17f6d3978039edae1dfae3ad16bea Mon Sep 17 00:00:00 2001 From: Simon Goldschmidt Date: Mon, 10 Oct 2011 21:06:50 +0200 Subject: [PATCH] Added unit test case for persist timer / zero window probes --- test/unit/tcp/tcp_helper.c | 71 +++++++++++----- test/unit/tcp/tcp_helper.h | 4 + test/unit/tcp/test_tcp.c | 160 ++++++++++++++++++++++++++++++++++++- 3 files changed, 213 insertions(+), 22 deletions(-) diff --git a/test/unit/tcp/tcp_helper.c b/test/unit/tcp/tcp_helper.c index fe4f43c4..e64a3aff 100644 --- a/test/unit/tcp/tcp_helper.c +++ b/test/unit/tcp/tcp_helper.c @@ -36,23 +36,11 @@ tcp_remove_all(void) fail_unless(lwip_stats.memp[MEMP_PBUF_POOL].used == 0); } -/** Create a TCP segment usable for passing to tcp_input - * - IP-addresses, ports, seqno and ackno are taken from pcb - * - seqno and ackno can be altered with an offset - */ -struct pbuf* -tcp_create_rx_segment(struct tcp_pcb* pcb, void* data, size_t data_len, u32_t seqno_offset, - u32_t ackno_offset, u8_t headerflags) -{ - return tcp_create_segment(&pcb->remote_ip, &pcb->local_ip, pcb->remote_port, pcb->local_port, - data, data_len, pcb->rcv_nxt + seqno_offset, pcb->lastack + ackno_offset, headerflags); -} - /** Create a TCP segment usable for passing to tcp_input */ -struct pbuf* -tcp_create_segment(ip_addr_t* src_ip, ip_addr_t* dst_ip, +static struct pbuf* +tcp_create_segment_wnd(ip_addr_t* src_ip, ip_addr_t* dst_ip, u16_t src_port, u16_t dst_port, void* data, size_t data_len, - u32_t seqno, u32_t ackno, u8_t headerflags) + u32_t seqno, u32_t ackno, u8_t headerflags, u16_t wnd) { struct pbuf *p, *q; struct ip_hdr* iphdr; @@ -90,7 +78,7 @@ tcp_create_segment(ip_addr_t* src_ip, ip_addr_t* dst_ip, tcphdr->ackno = htonl(ackno); TCPH_HDRLEN_SET(tcphdr, sizeof(struct tcp_hdr)/4); TCPH_FLAGS_SET(tcphdr, headerflags); - tcphdr->wnd = htons(TCP_WND); + tcphdr->wnd = htons(wnd); if (data_len > 0) { /* let p point to TCP data */ @@ -111,6 +99,40 @@ tcp_create_segment(ip_addr_t* src_ip, ip_addr_t* dst_ip, return p; } +/** Create a TCP segment usable for passing to tcp_input */ +struct pbuf* +tcp_create_segment(ip_addr_t* src_ip, ip_addr_t* dst_ip, + u16_t src_port, u16_t dst_port, void* data, size_t data_len, + u32_t seqno, u32_t ackno, u8_t headerflags) +{ + return tcp_create_segment_wnd(src_ip, dst_ip, src_port, dst_port, data, + data_len, seqno, ackno, headerflags, TCP_WND); +} + +/** Create a TCP segment usable for passing to tcp_input + * - IP-addresses, ports, seqno and ackno are taken from pcb + * - seqno and ackno can be altered with an offset + */ +struct pbuf* +tcp_create_rx_segment(struct tcp_pcb* pcb, void* data, size_t data_len, u32_t seqno_offset, + u32_t ackno_offset, u8_t headerflags) +{ + return tcp_create_segment(&pcb->remote_ip, &pcb->local_ip, pcb->remote_port, pcb->local_port, + data, data_len, pcb->rcv_nxt + seqno_offset, pcb->lastack + ackno_offset, headerflags); +} + +/** Create a TCP segment usable for passing to tcp_input + * - IP-addresses, ports, seqno and ackno are taken from pcb + * - seqno and ackno can be altered with an offset + * - TCP window can be adjusted + */ +struct pbuf* tcp_create_rx_segment_wnd(struct tcp_pcb* pcb, void* data, size_t data_len, + u32_t seqno_offset, u32_t ackno_offset, u8_t headerflags, u16_t wnd) +{ + return tcp_create_segment_wnd(&pcb->remote_ip, &pcb->local_ip, pcb->remote_port, pcb->local_port, + data, data_len, pcb->rcv_nxt + seqno_offset, pcb->lastack + ackno_offset, headerflags, wnd); +} + /** Safely bring a tcp_pcb into the requested state */ void tcp_set_state(struct tcp_pcb* pcb, enum tcp_state state, ip_addr_t* local_ip, @@ -237,11 +259,18 @@ static err_t test_tcp_netif_output(struct netif *netif, struct pbuf *p, LWIP_UNUSED_ARG(ipaddr); txcounters->num_tx_calls++; txcounters->num_tx_bytes += p->tot_len; - /*if (txcounters->tx_packets == NULL) { - txcounters->tx_packets = p; - } else { - pbuf_cat(txcounters->tx_packets, p); - }*/ + if (txcounters->copy_tx_packets) { + struct pbuf *p_copy = pbuf_alloc(PBUF_LINK, p->tot_len, PBUF_RAM); + err_t err; + EXPECT(p_copy != NULL); + err = pbuf_copy(p_copy, p); + EXPECT(err == ERR_OK); + if (txcounters->tx_packets == NULL) { + txcounters->tx_packets = p_copy; + } else { + pbuf_cat(txcounters->tx_packets, p_copy); + } + } return ERR_OK; } diff --git a/test/unit/tcp/tcp_helper.h b/test/unit/tcp/tcp_helper.h index d82cef54..4a72c935 100644 --- a/test/unit/tcp/tcp_helper.h +++ b/test/unit/tcp/tcp_helper.h @@ -22,6 +22,8 @@ struct test_tcp_counters { struct test_tcp_txcounters { u32_t num_tx_calls; u32_t num_tx_bytes; + u8_t copy_tx_packets; + struct pbuf *tx_packets; }; /* Helper functions */ @@ -32,6 +34,8 @@ struct pbuf* tcp_create_segment(ip_addr_t* src_ip, ip_addr_t* dst_ip, u32_t seqno, u32_t ackno, u8_t headerflags); struct pbuf* tcp_create_rx_segment(struct tcp_pcb* pcb, void* data, size_t data_len, u32_t seqno_offset, u32_t ackno_offset, u8_t headerflags); +struct pbuf* tcp_create_rx_segment_wnd(struct tcp_pcb* pcb, void* data, size_t data_len, + u32_t seqno_offset, u32_t ackno_offset, u8_t headerflags, u16_t wnd); void tcp_set_state(struct tcp_pcb* pcb, enum tcp_state state, ip_addr_t* local_ip, ip_addr_t* remote_ip, u16_t local_port, u16_t remote_port); void test_tcp_counters_err(void* arg, err_t err); diff --git a/test/unit/tcp/test_tcp.c b/test/unit/tcp/test_tcp.c index 7b5535c1..23903a89 100644 --- a/test/unit/tcp/test_tcp.c +++ b/test/unit/tcp/test_tcp.c @@ -7,6 +7,9 @@ #if !LWIP_STATS || !TCP_STATS || !MEMP_STATS #error "This tests needs TCP- and MEMP-statistics enabled" #endif +#if TCP_SND_BUF <= TCP_WND +#error "This tests needs TCP_SND_BUF to be > TCP_WND" +#endif /* Setups/teardown functions */ @@ -265,6 +268,159 @@ START_TEST(test_tcp_fast_retx_recover) } END_TEST +static u8_t tx_data[TCP_WND*2]; + +/** Provoke fast retransmission by duplicate ACKs and then recover by ACKing all sent data. + * At the end, send more data. */ +static void test_tcp_tx_full_window_lost(u8_t zero_window_probe_from_unsent) +{ + struct netif netif; + struct test_tcp_txcounters txcounters; + struct test_tcp_counters counters; + struct tcp_pcb* pcb; + struct pbuf *p; + ip_addr_t remote_ip, local_ip, netmask; + u16_t remote_port = 0x100, local_port = 0x101; + err_t err; + u16_t sent_total, i; + u8_t expected = 0xFE; + + for (i = 0; i < sizeof(tx_data); i++) { + u8_t d = (u8_t)i; + if (d == 0xFE) { + d = 0xF0; + } + tx_data[i] = d; + } + if (zero_window_probe_from_unsent) { + tx_data[TCP_WND] = expected; + } else { + tx_data[0] = expected; + } + + /* initialize local vars */ + IP4_ADDR(&local_ip, 192, 168, 1, 1); + IP4_ADDR(&remote_ip, 192, 168, 1, 2); + IP4_ADDR(&netmask, 255, 255, 255, 0); + test_tcp_init_netif(&netif, &txcounters, &local_ip, &netmask); + memset(&counters, 0, sizeof(counters)); + memset(&txcounters, 0, sizeof(txcounters)); + + /* create and initialize the pcb */ + pcb = test_tcp_new_counters_pcb(&counters); + EXPECT_RET(pcb != NULL); + tcp_set_state(pcb, ESTABLISHED, &local_ip, &remote_ip, local_port, remote_port); + pcb->mss = TCP_MSS; + /* disable initial congestion window (we don't send a SYN here...) */ + pcb->cwnd = pcb->snd_wnd; + + /* send a full window (minus 1 packets) of TCP data in MSS-sized chunks */ + sent_total = 0; + if ((TCP_WND - TCP_MSS) % TCP_MSS != 0) { + u16_t initial_data_len = (TCP_WND - TCP_MSS) % TCP_MSS; + err = tcp_write(pcb, &tx_data[sent_total], initial_data_len, TCP_WRITE_FLAG_COPY); + EXPECT_RET(err == ERR_OK); + err = tcp_output(pcb); + EXPECT_RET(err == ERR_OK); + EXPECT(txcounters.num_tx_calls == 1); + EXPECT(txcounters.num_tx_bytes == initial_data_len + 40U); + memset(&txcounters, 0, sizeof(txcounters)); + sent_total += initial_data_len; + } + for (; sent_total < (TCP_WND - TCP_MSS); sent_total += TCP_MSS) { + err = tcp_write(pcb, &tx_data[sent_total], TCP_MSS, TCP_WRITE_FLAG_COPY); + EXPECT_RET(err == ERR_OK); + err = tcp_output(pcb); + EXPECT_RET(err == ERR_OK); + EXPECT(txcounters.num_tx_calls == 1); + EXPECT(txcounters.num_tx_bytes == TCP_MSS + 40U); + memset(&txcounters, 0, sizeof(txcounters)); + } + EXPECT(sent_total == (TCP_WND - TCP_MSS)); + + /* now ACK the packet before the first */ + p = tcp_create_rx_segment(pcb, NULL, 0, 0, 0, TCP_ACK); + test_tcp_input(p, &netif); + /* ensure this didn't trigger a retransmission */ + EXPECT(txcounters.num_tx_calls == 0); + EXPECT(txcounters.num_tx_bytes == 0); + + /* send the last packet, now a complete window has been sent */ + err = tcp_write(pcb, &tx_data[sent_total], TCP_MSS, TCP_WRITE_FLAG_COPY); + sent_total += TCP_MSS; + EXPECT_RET(err == ERR_OK); + err = tcp_output(pcb); + EXPECT_RET(err == ERR_OK); + EXPECT(txcounters.num_tx_calls == 1); + EXPECT(txcounters.num_tx_bytes == TCP_MSS + 40U); + memset(&txcounters, 0, sizeof(txcounters)); + + if (zero_window_probe_from_unsent) { + /* ACK all data but close the TX window */ + p = tcp_create_rx_segment_wnd(pcb, NULL, 0, 0, TCP_WND, TCP_ACK, 0); + test_tcp_input(p, &netif); + /* ensure this didn't trigger any transmission */ + EXPECT(txcounters.num_tx_calls == 0); + EXPECT(txcounters.num_tx_bytes == 0); + } + + /* send one byte more (out of window) -> persist timer starts */ + err = tcp_write(pcb, &tx_data[sent_total], 1, TCP_WRITE_FLAG_COPY); + EXPECT_RET(err == ERR_OK); + err = tcp_output(pcb); + EXPECT_RET(err == ERR_OK); + EXPECT(txcounters.num_tx_calls == 0); + EXPECT(txcounters.num_tx_bytes == 0); + memset(&txcounters, 0, sizeof(txcounters)); + + /* call tcp_timer some more times to let persist timer count up */ + if (zero_window_probe_from_unsent) { + tcp_tmr(); + } + for (i = 0; i < 4; i++) { + tcp_tmr(); + EXPECT(txcounters.num_tx_calls == 0); + EXPECT(txcounters.num_tx_bytes == 0); + } + + /* this should trigger the zero-window-probe */ + txcounters.copy_tx_packets = 1; + tcp_tmr(); + txcounters.copy_tx_packets = 0; + EXPECT(txcounters.num_tx_calls == 1); + EXPECT(txcounters.num_tx_bytes == 1 + 40U); + EXPECT(txcounters.tx_packets != NULL); + if (txcounters.tx_packets != NULL) { + u8_t sent; + u16_t ret; + ret = pbuf_copy_partial(txcounters.tx_packets, &sent, 1, 40U); + EXPECT(ret == 1); + EXPECT(sent == expected); + } + if (txcounters.tx_packets != NULL) { + pbuf_free(txcounters.tx_packets); + txcounters.tx_packets = NULL; + } + + /* make sure the pcb is freed */ + EXPECT_RET(lwip_stats.memp[MEMP_TCP_PCB].used == 1); + tcp_abort(pcb); + EXPECT_RET(lwip_stats.memp[MEMP_TCP_PCB].used == 0); +} + +START_TEST(test_tcp_tx_full_window_lost_from_unsent) +{ + LWIP_UNUSED_ARG(_i); + test_tcp_tx_full_window_lost(1); +} +END_TEST + +START_TEST(test_tcp_tx_full_window_lost_from_unacked) +{ + LWIP_UNUSED_ARG(_i); + test_tcp_tx_full_window_lost(0); +} +END_TEST /** Create the suite including all tests for this module */ Suite * @@ -273,7 +429,9 @@ tcp_suite(void) TFun tests[] = { test_tcp_new_abort, test_tcp_recv_inseq, - test_tcp_fast_retx_recover + test_tcp_fast_retx_recover, + test_tcp_tx_full_window_lost_from_unacked, + test_tcp_tx_full_window_lost_from_unsent }; return create_suite("TCP", tests, sizeof(tests)/sizeof(TFun), tcp_setup, tcp_teardown); }