本文目录

• 1、服务端和客户端配置参数交换过程和状态机变化
• 2、服务端代码调用过程
• 3、客户端代码调用过程
• 4、哪些参数会被客户端同步到服务端

由文章
七，iperf3源代码分析：状态机及状态转换过程—＞运行正向TCP单向测试时的服务端代码
八，iperf3源代码分析：状态机及状态转换过程—＞运行正向TCP单向测试时的客户端代码
九，iperf3源代码分析：main函数主要流程，正向TCP单向测试时服务端和客户端的交互过程详解
我们知道服务端和客户端配置参数交换过程和状态机变化过程如下（注意：只有iperf3客户端会把配置参数发送给服务端，服务端的参数是不会发送到客户端的）：

1、服务端和客户端配置参数交换过程和状态机变化

1）当服务端收到客户端发过来的控制连接建立请求后，就会接收连接请求，并成功的建立连接请求后放在test->ctrl_sck指针里，
2）然后服务端主动进入PARAM_EXCHANGE状态，并给客户端发送PARAM_EXCHANGE指令
3）客户端收到PARAM_EXCHANGE指令后，就开始通过test->ctrl_sck指针指向的控制连接向服务端发送配置参数
4）服务端收到配置参数后，保存并进行配置，进行CREATE_STREAM状态后完成配置参数交换过程

如下图所示左边是客户端，右边是服务端：

2、服务端代码调用过程

iperf_exchange_parameters—>get_parameters—>JSON_read,
通过test->ctrl_sck 控制连接，将接收到的参数解析后，存入test->指针下的各个参数配置项里，完成参数交换。

debug out: set the state from 15 to 9
debug out: func = iperf_exchange_parameters,line = 2087, file = iperf_api.c
debug out: func = get_parameters           ,line = 2268, file = iperf_api.c
debug out: func = JSON_read                ,line = 2662, file = iperf_api.c
get_parameters:
{"udp":	true,"omit":	0,"time":	0,"num":	8192,"blockcount":	0,"parallel":	1,"len":	1024,"bandwidth":	1048576,"pacing_timer":	1000,"client_version":	"3.13"
}
debug out: func = iperf_exchange_parameters,line = 2104, file = iperf_api.c

3、客户端代码调用过程

iperf_exchange_parameters—>send_parameters—>JSON_write
将客户端的参数以JSON的格式，通过test->ctrl_sck 控制连接，将参数发送到服务端。

debug out: receive and change the state from 0 to 9
debug out: func = iperf_exchange_parameters,line = 2082, file = iperf_api.c
debug out: func = send_parameters          ,line = 2166, file = iperf_api.c
send_parameters:
{"udp":	true,"omit":	0,"time":	0,"num":	8192,"blockcount":	0,"parallel":	1,"len":	1024,"bandwidth":	1048576,"pacing_timer":	1000,"client_version":	"3.13"
}
debug out: func = send_parameters          ,line = 2250, file = iperf_api.c
debug out: func = JSON_write               ,line = 2635, file = iperf_api.c

4、哪些参数会被客户端同步到服务端

通过send_parameters函数，我们可以看到以下参数会被从客户端发送到服务端：

具体源代码参见客户端调用的send_parameters和服务端调用的get_parameters二个函数

static int
send_parameters(struct iperf_test *test)
{int r = 0;cJSON *j;PRINTFILEFUNCLINEj = cJSON_CreateObject();if (j == NULL) {i_errno = IESENDPARAMS;r = -1;} else {if (test->protocol->id == Ptcp)cJSON_AddTrueToObject(j, "tcp");else if (test->protocol->id == Pudp)cJSON_AddTrueToObject(j, "udp");else if (test->protocol->id == Psctp)cJSON_AddTrueToObject(j, "sctp");cJSON_AddNumberToObject(j, "omit", test->omit);if (test->server_affinity != -1)cJSON_AddNumberToObject(j, "server_affinity", test->server_affinity);cJSON_AddNumberToObject(j, "time", test->duration);cJSON_AddNumberToObject(j, "num", test->settings->bytes);cJSON_AddNumberToObject(j, "blockcount", test->settings->blocks);if (test->settings->mss)cJSON_AddNumberToObject(j, "MSS", test->settings->mss);if (test->no_delay)cJSON_AddTrueToObject(j, "nodelay");cJSON_AddNumberToObject(j, "parallel", test->num_streams);if (test->reverse)cJSON_AddTrueToObject(j, "reverse");if (test->bidirectional)cJSON_AddTrueToObject(j, "bidirectional");if (test->settings->socket_bufsize)cJSON_AddNumberToObject(j, "window", test->settings->socket_bufsize);if (test->settings->blksize)cJSON_AddNumberToObject(j, "len", test->settings->blksize);if (test->settings->rate)cJSON_AddNumberToObject(j, "bandwidth", test->settings->rate);if (test->settings->fqrate)cJSON_AddNumberToObject(j, "fqrate", test->settings->fqrate);if (test->settings->pacing_timer)cJSON_AddNumberToObject(j, "pacing_timer", test->settings->pacing_timer);if (test->settings->burst)cJSON_AddNumberToObject(j, "burst", test->settings->burst);if (test->settings->tos)cJSON_AddNumberToObject(j, "TOS", test->settings->tos);if (test->settings->flowlabel)cJSON_AddNumberToObject(j, "flowlabel", test->settings->flowlabel);if (test->title)cJSON_AddStringToObject(j, "title", test->title);if (test->extra_data)cJSON_AddStringToObject(j, "extra_data", test->extra_data);if (test->congestion)cJSON_AddStringToObject(j, "congestion", test->congestion);if (test->congestion_used)cJSON_AddStringToObject(j, "congestion_used", test->congestion_used);if (test->get_server_output)cJSON_AddNumberToObject(j, "get_server_output", iperf_get_test_get_server_output(test));if (test->udp_counters_64bit)cJSON_AddNumberToObject(j, "udp_counters_64bit", iperf_get_test_udp_counters_64bit(test));if (test->repeating_payload)cJSON_AddNumberToObject(j, "repeating_payload", test->repeating_payload);if (test->zerocopy)cJSON_AddNumberToObject(j, "zerocopy", test->zerocopy);
#if defined(HAVE_DONT_FRAGMENT)if (test->settings->dont_fragment)cJSON_AddNumberToObject(j, "dont_fragment", test->settings->dont_fragment);
#endif /* HAVE_DONT_FRAGMENT */
#if defined(HAVE_SSL)/* Send authentication parameters */if (test->settings->client_username && test->settings->client_password && test->settings->client_rsa_pubkey){int rc = encode_auth_setting(test->settings->client_username, test->settings->client_password, test->settings->client_rsa_pubkey, &test->settings->authtoken);if (rc) {cJSON_Delete(j);i_errno = IESENDPARAMS;return -1;}cJSON_AddStringToObject(j, "authtoken", test->settings->authtoken);}
#endif // HAVE_SSLcJSON_AddStringToObject(j, "client_version", IPERF_VERSION);if (test->debug) {char *str = cJSON_Print(j);printf("send_parameters:\n%s\n", str);cJSON_free(str);}PRINTFILEFUNCLINEif (JSON_write(test->ctrl_sck, j) < 0) {i_errno = IESENDPARAMS;r = -1;}cJSON_Delete(j);}return r;
}#----------------------------------------------------------------------------
static int
get_parameters(struct iperf_test *test)
{int r = 0;cJSON *j;cJSON *j_p;PRINTFILEFUNCLINEj = JSON_read(test->ctrl_sck);if (j == NULL) {i_errno = IERECVPARAMS;r = -1;} else {if (test->debug) {char *str;str = cJSON_Print(j);printf("get_parameters:\n%s\n", str );cJSON_free(str);}if ((j_p = cJSON_GetObjectItem(j, "tcp")) != NULL)set_protocol(test, Ptcp);if ((j_p = cJSON_GetObjectItem(j, "udp")) != NULL)set_protocol(test, Pudp);if ((j_p = cJSON_GetObjectItem(j, "sctp")) != NULL)set_protocol(test, Psctp);if ((j_p = cJSON_GetObjectItem(j, "omit")) != NULL)test->omit = j_p->valueint;if ((j_p = cJSON_GetObjectItem(j, "server_affinity")) != NULL)test->server_affinity = j_p->valueint;if ((j_p = cJSON_GetObjectItem(j, "time")) != NULL)test->duration = j_p->valueint;test->settings->bytes = 0;if ((j_p = cJSON_GetObjectItem(j, "num")) != NULL)test->settings->bytes = j_p->valueint;test->settings->blocks = 0;if ((j_p = cJSON_GetObjectItem(j, "blockcount")) != NULL)test->settings->blocks = j_p->valueint;if ((j_p = cJSON_GetObjectItem(j, "MSS")) != NULL)test->settings->mss = j_p->valueint;if ((j_p = cJSON_GetObjectItem(j, "nodelay")) != NULL)test->no_delay = 1;if ((j_p = cJSON_GetObjectItem(j, "parallel")) != NULL)test->num_streams = j_p->valueint;if ((j_p = cJSON_GetObjectItem(j, "reverse")) != NULL)iperf_set_test_reverse(test, 1);if ((j_p = cJSON_GetObjectItem(j, "bidirectional")) != NULL)iperf_set_test_bidirectional(test, 1);if ((j_p = cJSON_GetObjectItem(j, "window")) != NULL)test->settings->socket_bufsize = j_p->valueint;if ((j_p = cJSON_GetObjectItem(j, "len")) != NULL)test->settings->blksize = j_p->valueint;if ((j_p = cJSON_GetObjectItem(j, "bandwidth")) != NULL)test->settings->rate = j_p->valueint;if ((j_p = cJSON_GetObjectItem(j, "fqrate")) != NULL)test->settings->fqrate = j_p->valueint;if ((j_p = cJSON_GetObjectItem(j, "pacing_timer")) != NULL)test->settings->pacing_timer = j_p->valueint;if ((j_p = cJSON_GetObjectItem(j, "burst")) != NULL)test->settings->burst = j_p->valueint;if ((j_p = cJSON_GetObjectItem(j, "TOS")) != NULL)test->settings->tos = j_p->valueint;if ((j_p = cJSON_GetObjectItem(j, "flowlabel")) != NULL)test->settings->flowlabel = j_p->valueint;if ((j_p = cJSON_GetObjectItem(j, "title")) != NULL)test->title = strdup(j_p->valuestring);if ((j_p = cJSON_GetObjectItem(j, "extra_data")) != NULL)test->extra_data = strdup(j_p->valuestring);if ((j_p = cJSON_GetObjectItem(j, "congestion")) != NULL)test->congestion = strdup(j_p->valuestring);if ((j_p = cJSON_GetObjectItem(j, "congestion_used")) != NULL)test->congestion_used = strdup(j_p->valuestring);if ((j_p = cJSON_GetObjectItem(j, "get_server_output")) != NULL)iperf_set_test_get_server_output(test, 1);if ((j_p = cJSON_GetObjectItem(j, "udp_counters_64bit")) != NULL)iperf_set_test_udp_counters_64bit(test, 1);if ((j_p = cJSON_GetObjectItem(j, "repeating_payload")) != NULL)test->repeating_payload = 1;if ((j_p = cJSON_GetObjectItem(j, "zerocopy")) != NULL)test->zerocopy = j_p->valueint;
#if defined(HAVE_DONT_FRAGMENT)if ((j_p = cJSON_GetObjectItem(j, "dont_fragment")) != NULL)test->settings->dont_fragment = j_p->valueint;
#endif /* HAVE_DONT_FRAGMENT */
#if defined(HAVE_SSL)if ((j_p = cJSON_GetObjectItem(j, "authtoken")) != NULL)test->settings->authtoken = strdup(j_p->valuestring);
#endif //HAVE_SSLif (test->mode && test->protocol->id == Ptcp && has_tcpinfo_retransmits())test->sender_has_retransmits = 1;if (test->settings->rate)cJSON_AddNumberToObject(test->json_start, "target_bitrate", test->settings->rate);cJSON_Delete(j);}return r;
}