1/**
2 * @file
3 * lwIP iPerf server implementation
4 */
5
6/**
7 * @defgroup iperf Iperf server
8 * @ingroup apps
9 *
10 * This is a simple performance measuring server to check your bandwith using
11 * iPerf2 on a PC as client.
12 * It is currently a minimal implementation providing an IPv4 TCP server only.
13 *
14 * @todo: implement UDP mode and IPv6
15 */
16
17/*
18 * Copyright (c) 2014 Simon Goldschmidt
19 * All rights reserved.
20 *
21 * Redistribution and use in source and binary forms, with or without modification,
22 * are permitted provided that the following conditions are met:
23 *
24 * 1. Redistributions of source code must retain the above copyright notice,
25 *    this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright notice,
27 *    this list of conditions and the following disclaimer in the documentation
28 *    and/or other materials provided with the distribution.
29 * 3. The name of the author may not be used to endorse or promote products
30 *    derived from this software without specific prior written permission.
31 *
32 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
33 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
34 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
35 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
36 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
37 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
38 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
39 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
41 * OF SUCH DAMAGE.
42 *
43 * This file is part of the lwIP TCP/IP stack.
44 *
45 * Author: Simon Goldschmidt
46 */
47
48#include "lwip/apps/lwiperf.h"
49
50#include "lwip/tcp.h"
51#include "lwip/sys.h"
52
53#include <string.h>
54
55/* Currently, only TCP-over-IPv4 is implemented (does iperf support IPv6 anyway?) */
56#if LWIP_IPV4 && LWIP_TCP && LWIP_CALLBACK_API
57
58/** Specify the idle timeout (in seconds) after that the test fails */
59#ifndef LWIPERF_TCP_MAX_IDLE_SEC
60#define LWIPERF_TCP_MAX_IDLE_SEC    10U
61#endif
62#if LWIPERF_TCP_MAX_IDLE_SEC > 255
63#error LWIPERF_TCP_MAX_IDLE_SEC must fit into an u8_t
64#endif
65
66/* File internal memory allocation (struct lwiperf_*): this defaults to
67   the heap */
68#ifndef LWIPERF_ALLOC
69#define LWIPERF_ALLOC(type)         mem_malloc(sizeof(type))
70#define LWIPERF_FREE(type, item)    mem_free(item)
71#endif
72
73/** If this is 1, check that received data has the correct format */
74#ifndef LWIPERF_CHECK_RX_DATA
75#define LWIPERF_CHECK_RX_DATA       0
76#endif
77
78/** This is the Iperf settings struct sent from the client */
79typedef struct _lwiperf_settings {
80#define LWIPERF_FLAGS_ANSWER_TEST 0x80000000
81#define LWIPERF_FLAGS_ANSWER_NOW  0x00000001
82  u32_t flags;
83  u32_t num_threads; /* unused for now */
84  u32_t remote_port;
85  u32_t buffer_len; /* unused for now */
86  u32_t win_band; /* TCP window / UDP rate: unused for now */
87  u32_t amount; /* pos. value: bytes?; neg. values: time (unit is 10ms: 1/100 second) */
88} lwiperf_settings_t;
89
90/** Basic connection handle */
91struct _lwiperf_state_base;
92typedef struct _lwiperf_state_base lwiperf_state_base_t;
93struct _lwiperf_state_base {
94  /* 1=tcp, 0=udp */
95  u8_t tcp;
96  /* 1=server, 0=client */
97  u8_t server;
98  lwiperf_state_base_t* next;
99  lwiperf_state_base_t* related_server_state;
100};
101
102/** Connection handle for a TCP iperf session */
103typedef struct _lwiperf_state_tcp {
104  lwiperf_state_base_t base;
105  struct tcp_pcb* server_pcb;
106  struct tcp_pcb* conn_pcb;
107  u32_t time_started;
108  lwiperf_report_fn report_fn;
109  void* report_arg;
110  u8_t poll_count;
111  u8_t next_num;
112  u32_t bytes_transferred;
113  lwiperf_settings_t settings;
114  u8_t have_settings_buf;
115} lwiperf_state_tcp_t;
116
117/** List of active iperf sessions */
118static lwiperf_state_base_t* lwiperf_all_connections;
119/** A const buffer to send from: we want to measure sending, not copying! */
120static const u8_t lwiperf_txbuf_const[1600] = {
121  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
122  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
123  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
124  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
125  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
126  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
127  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
128  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
129  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
130  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
131  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
132  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
133  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
134  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
135  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
136  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
137  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
138  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
139  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
140  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
141  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
142  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
143  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
144  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
145  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
146  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
147  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
148  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
149  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
150  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
151  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
152  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
153  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
154  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
155  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
156  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
157  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
158  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
159  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
160  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
161};
162
163static err_t lwiperf_tcp_poll(void *arg, struct tcp_pcb *tpcb);
164static void lwiperf_tcp_err(void *arg, err_t err);
165
166/** Add an iperf session to the 'active' list */
167static void
168lwiperf_list_add(lwiperf_state_base_t* item)
169{
170  if (lwiperf_all_connections == NULL) {
171    lwiperf_all_connections = item;
172  } else {
173    item = lwiperf_all_connections;
174  }
175}
176
177/** Remove an iperf session from the 'active' list */
178static void
179lwiperf_list_remove(lwiperf_state_base_t* item)
180{
181  lwiperf_state_base_t* prev = NULL;
182  lwiperf_state_base_t* iter;
183  for (iter = lwiperf_all_connections; iter != NULL; prev = iter, iter = iter->next) {
184    if (iter == item) {
185      if (prev == NULL) {
186        lwiperf_all_connections = iter->next;
187      } else {
188        prev->next = item;
189      }
190      /* @debug: ensure this item is listed only once */
191      for (iter = iter->next; iter != NULL; iter = iter->next) {
192        LWIP_ASSERT("duplicate entry", iter != item);
193      }
194      break;
195    }
196  }
197}
198
199/** Call the report function of an iperf tcp session */
200static void
201lwip_tcp_conn_report(lwiperf_state_tcp_t* conn, enum lwiperf_report_type report_type)
202{
203  if ((conn != NULL) && (conn->report_fn != NULL)) {
204    u32_t now, duration_ms, bandwidth_kbitpsec;
205    now = sys_now();
206    duration_ms = now - conn->time_started;
207    if (duration_ms == 0) {
208      bandwidth_kbitpsec = 0;
209    } else {
210      bandwidth_kbitpsec = (conn->bytes_transferred / duration_ms) * 8U;
211    }
212    conn->report_fn(conn->report_arg, report_type,
213      &conn->conn_pcb->local_ip, conn->conn_pcb->local_port,
214      &conn->conn_pcb->remote_ip, conn->conn_pcb->remote_port,
215      conn->bytes_transferred, duration_ms, bandwidth_kbitpsec);
216  }
217}
218
219/** Close an iperf tcp session */
220static void
221lwiperf_tcp_close(lwiperf_state_tcp_t* conn, enum lwiperf_report_type report_type)
222{
223  err_t err;
224
225  lwip_tcp_conn_report(conn, report_type);
226  lwiperf_list_remove(&conn->base);
227  if (conn->conn_pcb != NULL) {
228    tcp_arg(conn->conn_pcb, NULL);
229    tcp_poll(conn->conn_pcb, NULL, 0);
230    tcp_sent(conn->conn_pcb, NULL);
231    tcp_recv(conn->conn_pcb, NULL);
232    tcp_err(conn->conn_pcb, NULL);
233    err = tcp_close(conn->conn_pcb);
234    if (err != ERR_OK) {
235      /* don't want to wait for free memory here... */
236      tcp_abort(conn->conn_pcb);
237    }
238  } else {
239    /* no conn pcb, this is the server pcb */
240    err = tcp_close(conn->server_pcb);
241    LWIP_ASSERT("error", err != ERR_OK);
242  }
243  LWIPERF_FREE(lwiperf_state_tcp_t, conn);
244}
245
246/** Try to send more data on an iperf tcp session */
247static err_t
248lwiperf_tcp_client_send_more(lwiperf_state_tcp_t* conn)
249{
250  int send_more;
251  err_t err;
252  u16_t txlen;
253  u16_t txlen_max;
254  void* txptr;
255  u8_t apiflags;
256
257  LWIP_ASSERT("conn invalid", (conn != NULL) && conn->base.tcp && (conn->base.server == 0));
258
259  do {
260    send_more = 0;
261    if (conn->settings.amount & PP_HTONL(0x80000000)) {
262      /* this session is time-limited */
263      u32_t now = sys_now();
264      u32_t diff_ms = now - conn->time_started;
265      u32_t time = (u32_t)-(s32_t)lwip_htonl(conn->settings.amount);
266      u32_t time_ms = time * 10;
267      if (diff_ms >= time_ms) {
268        /* time specified by the client is over -> close the connection */
269        lwiperf_tcp_close(conn, LWIPERF_TCP_DONE_CLIENT);
270        return ERR_OK;
271      }
272    } else {
273      /* this session is byte-limited */
274      u32_t amount_bytes = lwip_htonl(conn->settings.amount);
275      /* @todo: this can send up to 1*MSS more than requested... */
276      if (amount_bytes >= conn->bytes_transferred) {
277        /* all requested bytes transferred -> close the connection */
278        lwiperf_tcp_close(conn, LWIPERF_TCP_DONE_CLIENT);
279        return ERR_OK;
280      }
281    }
282
283    if (conn->bytes_transferred < 24) {
284      /* transmit the settings a first time */
285      txptr = &((u8_t*)&conn->settings)[conn->bytes_transferred];
286      txlen_max = (u16_t)(24 - conn->bytes_transferred);
287      apiflags = TCP_WRITE_FLAG_COPY;
288    } else if (conn->bytes_transferred < 48) {
289      /* transmit the settings a second time */
290      txptr = &((u8_t*)&conn->settings)[conn->bytes_transferred - 24];
291      txlen_max = (u16_t)(48 - conn->bytes_transferred);
292      apiflags = TCP_WRITE_FLAG_COPY | TCP_WRITE_FLAG_MORE;
293      send_more = 1;
294    } else {
295      /* transmit data */
296      /* @todo: every x bytes, transmit the settings again */
297      txptr = LWIP_CONST_CAST(void*, &lwiperf_txbuf_const[conn->bytes_transferred % 10]);
298      txlen_max = TCP_MSS;
299      if (conn->bytes_transferred == 48) { /* @todo: fix this for intermediate settings, too */
300        txlen_max = TCP_MSS - 24;
301      }
302      apiflags = 0; /* no copying needed */
303      send_more = 1;
304    }
305    txlen = txlen_max;
306    do {
307      err = tcp_write(conn->conn_pcb, txptr, txlen, apiflags);
308      if (err ==  ERR_MEM) {
309        txlen /= 2;
310      }
311    } while ((err == ERR_MEM) && (txlen >= (TCP_MSS/2)));
312
313    if (err == ERR_OK) {
314      conn->bytes_transferred += txlen;
315    } else {
316      send_more = 0;
317    }
318  } while(send_more);
319
320  tcp_output(conn->conn_pcb);
321  return ERR_OK;
322}
323
324/** TCP sent callback, try to send more data */
325static err_t
326lwiperf_tcp_client_sent(void *arg, struct tcp_pcb *tpcb, u16_t len)
327{
328  lwiperf_state_tcp_t* conn = (lwiperf_state_tcp_t*)arg;
329  /* @todo: check 'len' (e.g. to time ACK of all data)? for now, we just send more... */
330  LWIP_ASSERT("invalid conn", conn->conn_pcb == tpcb);
331  LWIP_UNUSED_ARG(tpcb);
332  LWIP_UNUSED_ARG(len);
333
334  conn->poll_count = 0;
335
336  return lwiperf_tcp_client_send_more(conn);
337}
338
339/** TCP connected callback (active connection), send data now */
340static err_t
341lwiperf_tcp_client_connected(void *arg, struct tcp_pcb *tpcb, err_t err)
342{
343  lwiperf_state_tcp_t* conn = (lwiperf_state_tcp_t*)arg;
344  LWIP_ASSERT("invalid conn", conn->conn_pcb == tpcb);
345  LWIP_UNUSED_ARG(tpcb);
346  if (err != ERR_OK) {
347    lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_REMOTE);
348    return ERR_OK;
349  }
350  conn->poll_count = 0;
351  conn->time_started = sys_now();
352  return lwiperf_tcp_client_send_more(conn);
353}
354
355/** Start TCP connection back to the client (either parallel or after the
356 * receive test has finished.
357 */
358static err_t
359lwiperf_tx_start(lwiperf_state_tcp_t* conn)
360{
361  err_t err;
362  lwiperf_state_tcp_t* client_conn;
363  struct tcp_pcb* newpcb;
364  ip_addr_t remote_addr;
365  u16_t remote_port;
366
367  client_conn = (lwiperf_state_tcp_t*)LWIPERF_ALLOC(lwiperf_state_tcp_t);
368  if (client_conn == NULL) {
369    return ERR_MEM;
370  }
371  newpcb = tcp_new();
372  if (newpcb == NULL) {
373    LWIPERF_FREE(lwiperf_state_tcp_t, client_conn);
374    return ERR_MEM;
375  }
376
377  MEMCPY(client_conn, conn, sizeof(lwiperf_state_tcp_t));
378  client_conn->base.server = 0;
379  client_conn->server_pcb = NULL;
380  client_conn->conn_pcb = newpcb;
381  client_conn->time_started = sys_now(); /* @todo: set this again on 'connected' */
382  client_conn->poll_count = 0;
383  client_conn->next_num = 4; /* initial nr is '4' since the header has 24 byte */
384  client_conn->bytes_transferred = 0;
385  client_conn->settings.flags = 0; /* prevent the remote side starting back as client again */
386
387  tcp_arg(newpcb, client_conn);
388  tcp_sent(newpcb, lwiperf_tcp_client_sent);
389  tcp_poll(newpcb, lwiperf_tcp_poll, 2U);
390  tcp_err(newpcb, lwiperf_tcp_err);
391
392  ip_addr_copy(remote_addr, conn->conn_pcb->remote_ip);
393  remote_port = (u16_t)lwip_htonl(client_conn->settings.remote_port);
394
395  err = tcp_connect(newpcb, &remote_addr, remote_port, lwiperf_tcp_client_connected);
396  if (err != ERR_OK) {
397    lwiperf_tcp_close(client_conn, LWIPERF_TCP_ABORTED_LOCAL);
398    return err;
399  }
400  lwiperf_list_add(&client_conn->base);
401  return ERR_OK;
402}
403
404/** Receive data on an iperf tcp session */
405static err_t
406lwiperf_tcp_recv(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err)
407{
408  u8_t tmp;
409  u16_t tot_len;
410  u32_t packet_idx;
411  struct pbuf* q;
412  lwiperf_state_tcp_t* conn = (lwiperf_state_tcp_t*)arg;
413
414  LWIP_ASSERT("pcb mismatch", conn->conn_pcb == tpcb);
415  LWIP_UNUSED_ARG(tpcb);
416
417  if (err != ERR_OK) {
418    lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_REMOTE);
419    return ERR_OK;
420  }
421  if (p == NULL) {
422    /* connection closed -> test done */
423    if ((conn->settings.flags & PP_HTONL(LWIPERF_FLAGS_ANSWER_TEST|LWIPERF_FLAGS_ANSWER_NOW)) ==
424        PP_HTONL(LWIPERF_FLAGS_ANSWER_TEST)) {
425      /* client requested transmission after end of test */
426      lwiperf_tx_start(conn);
427    }
428    lwiperf_tcp_close(conn, LWIPERF_TCP_DONE_SERVER);
429    return ERR_OK;
430  }
431  tot_len = p->tot_len;
432
433  conn->poll_count = 0;
434
435  if ((!conn->have_settings_buf) || ((conn->bytes_transferred -24) % (1024*128) == 0)) {
436    /* wait for 24-byte header */
437    if (p->tot_len < sizeof(lwiperf_settings_t)) {
438      lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_LOCAL_DATAERROR);
439      pbuf_free(p);
440      return ERR_VAL;
441    }
442    if (!conn->have_settings_buf) {
443      if (pbuf_copy_partial(p, &conn->settings, sizeof(lwiperf_settings_t), 0) != sizeof(lwiperf_settings_t)) {
444        lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_LOCAL);
445        pbuf_free(p);
446        return ERR_VAL;
447      }
448      conn->have_settings_buf = 1;
449      if ((conn->settings.flags & PP_HTONL(LWIPERF_FLAGS_ANSWER_TEST|LWIPERF_FLAGS_ANSWER_NOW)) ==
450        PP_HTONL(LWIPERF_FLAGS_ANSWER_TEST|LWIPERF_FLAGS_ANSWER_NOW)) {
451          /* client requested parallel transmission test */
452          err_t err2 = lwiperf_tx_start(conn);
453          if (err2 != ERR_OK) {
454            lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_LOCAL_TXERROR);
455            pbuf_free(p);
456            return err2;
457          }
458      }
459    } else {
460      if (pbuf_memcmp(p, 0, &conn->settings, sizeof(lwiperf_settings_t)) != 0) {
461        lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_LOCAL_DATAERROR);
462        pbuf_free(p);
463        return ERR_VAL;
464      }
465    }
466    conn->bytes_transferred += sizeof(lwiperf_settings_t);
467    if (conn->bytes_transferred <= 24) {
468      conn->time_started = sys_now();
469      tcp_recved(tpcb, p->tot_len);
470      pbuf_free(p);
471      return ERR_OK;
472    }
473    conn->next_num = 4; /* 24 bytes received... */
474    tmp = pbuf_header(p, -24);
475    LWIP_ASSERT("pbuf_header failed", tmp == 0);
476  }
477
478  packet_idx = 0;
479  for (q = p; q != NULL; q = q->next) {
480#if LWIPERF_CHECK_RX_DATA
481    const u8_t* payload = (const u8_t*)q->payload;
482    u16_t i;
483    for (i = 0; i < q->len; i++) {
484      u8_t val = payload[i];
485      u8_t num = val - '0';
486      if (num == conn->next_num) {
487        conn->next_num++;
488        if (conn->next_num == 10) {
489          conn->next_num = 0;
490        }
491      } else {
492        lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_LOCAL_DATAERROR);
493        pbuf_free(p);
494        return ERR_VAL;
495      }
496    }
497#endif
498    packet_idx += q->len;
499  }
500  LWIP_ASSERT("count mismatch", packet_idx == p->tot_len);
501  conn->bytes_transferred += packet_idx;
502  tcp_recved(tpcb, tot_len);
503  pbuf_free(p);
504  return ERR_OK;
505}
506
507/** Error callback, iperf tcp session aborted */
508static void
509lwiperf_tcp_err(void *arg, err_t err)
510{
511  lwiperf_state_tcp_t* conn = (lwiperf_state_tcp_t*)arg;
512  LWIP_UNUSED_ARG(err);
513  lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_REMOTE);
514}
515
516/** TCP poll callback, try to send more data */
517static err_t
518lwiperf_tcp_poll(void *arg, struct tcp_pcb *tpcb)
519{
520  lwiperf_state_tcp_t* conn = (lwiperf_state_tcp_t*)arg;
521  LWIP_ASSERT("pcb mismatch", conn->conn_pcb == tpcb);
522  LWIP_UNUSED_ARG(tpcb);
523  if (++conn->poll_count >= LWIPERF_TCP_MAX_IDLE_SEC) {
524    lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_LOCAL);
525    return ERR_OK; /* lwiperf_tcp_close frees conn */
526  }
527
528  if (!conn->base.server) {
529    lwiperf_tcp_client_send_more(conn);
530  }
531
532  return ERR_OK;
533}
534
535/** This is called when a new client connects for an iperf tcp session */
536static err_t
537lwiperf_tcp_accept(void *arg, struct tcp_pcb *newpcb, err_t err)
538{
539  lwiperf_state_tcp_t *s, *conn;
540  if ((err != ERR_OK) || (newpcb == NULL) || (arg == NULL)) {
541    return ERR_VAL;
542  }
543
544  s = (lwiperf_state_tcp_t*)arg;
545  conn = (lwiperf_state_tcp_t*)LWIPERF_ALLOC(lwiperf_state_tcp_t);
546  if (conn == NULL) {
547    return ERR_MEM;
548  }
549  memset(conn, 0, sizeof(lwiperf_state_tcp_t));
550  conn->base.tcp = 1;
551  conn->base.server = 1;
552  conn->base.related_server_state = &s->base;
553  conn->server_pcb = s->server_pcb;
554  conn->conn_pcb = newpcb;
555  conn->time_started = sys_now();
556  conn->report_fn = s->report_fn;
557  conn->report_arg = s->report_arg;
558
559  /* setup the tcp rx connection */
560  tcp_arg(newpcb, conn);
561  tcp_recv(newpcb, lwiperf_tcp_recv);
562  tcp_poll(newpcb, lwiperf_tcp_poll, 2U);
563  tcp_err(conn->conn_pcb, lwiperf_tcp_err);
564
565  lwiperf_list_add(&conn->base);
566  return ERR_OK;
567}
568
569/**
570 * @ingroup iperf
571 * Start a TCP iperf server on the default TCP port (5001) and listen for
572 * incoming connections from iperf clients.
573 *
574 * @returns a connection handle that can be used to abort the server
575 *          by calling @ref lwiperf_abort()
576 */
577void*
578lwiperf_start_tcp_server_default(lwiperf_report_fn report_fn, void* report_arg)
579{
580  return lwiperf_start_tcp_server(IP_ADDR_ANY, LWIPERF_TCP_PORT_DEFAULT,
581    report_fn, report_arg);
582}
583
584/**
585 * @ingroup iperf
586 * Start a TCP iperf server on a specific IP address and port and listen for
587 * incoming connections from iperf clients.
588 *
589 * @returns a connection handle that can be used to abort the server
590 *          by calling @ref lwiperf_abort()
591 */
592void*
593lwiperf_start_tcp_server(const ip_addr_t* local_addr, u16_t local_port,
594  lwiperf_report_fn report_fn, void* report_arg)
595{
596  err_t err;
597  struct tcp_pcb* pcb;
598  lwiperf_state_tcp_t* s;
599
600  if (local_addr == NULL) {
601    return NULL;
602  }
603
604  s = (lwiperf_state_tcp_t*)LWIPERF_ALLOC(lwiperf_state_tcp_t);
605  if (s == NULL) {
606    return NULL;
607  }
608  memset(s, 0, sizeof(lwiperf_state_tcp_t));
609  s->base.tcp = 1;
610  s->base.server = 1;
611  s->report_fn = report_fn;
612  s->report_arg = report_arg;
613
614  pcb = tcp_new();
615  if (pcb != NULL) {
616    err = tcp_bind(pcb, local_addr, local_port);
617    if (err == ERR_OK) {
618      s->server_pcb = tcp_listen_with_backlog(pcb, 1);
619    }
620  }
621  if (s->server_pcb == NULL) {
622    if (pcb != NULL) {
623      tcp_close(pcb);
624    }
625    LWIPERF_FREE(lwiperf_state_tcp_t, s);
626    return NULL;
627  }
628  pcb = NULL;
629
630  tcp_arg(s->server_pcb, s);
631  tcp_accept(s->server_pcb, lwiperf_tcp_accept);
632
633  lwiperf_list_add(&s->base);
634  return s;
635}
636
637/**
638 * @ingroup iperf
639 * Abort an iperf session (handle returned by lwiperf_start_tcp_server*())
640 */
641void
642lwiperf_abort(void* lwiperf_session)
643{
644  lwiperf_state_base_t* i, *dealloc, *last = NULL;
645
646  for (i = lwiperf_all_connections; i != NULL; ) {
647    if ((i == lwiperf_session) || (i->related_server_state == lwiperf_session)) {
648      dealloc = i;
649      i = i->next;
650      if (last != NULL) {
651        last->next = i;
652      }
653      LWIPERF_FREE(lwiperf_state_tcp_t, dealloc); /* @todo: type? */
654    } else {
655      last = i;
656      i = i->next;
657    }
658  }
659}
660
661#endif /* LWIP_IPV4 && LWIP_TCP && LWIP_CALLBACK_API */
662