ESP8266 HTTPClient cannot be reused to connect to a second, different host · Issue #8331 · esp8266/Arduino (original) (raw)
Basic Infos
- This issue complies with the issue POLICY doc.
- I have read the documentation at readthedocs and the issue is not addressed there.
- I have tested that the issue is present in current master branch (aka latest git).
- I have searched the issue tracker for a similar issue.
- If there is a stack dump, I have decoded it. n/a
- I have filled out all fields below.
Platform
- Hardware: ESP8266
- Core Version: 9d024d1
- Development Env: PlatformIO
- Operating System: macOS 11.6
Settings in IDE
- Module: Wemos D1 mini r2
- Flash Mode: unknown
- Flash Size: 4MB/1MB
- lwip Variant: unknown
- Reset Method: unknown
- Flash Frequency: unknown
- CPU Frequency: 160MHz
- Upload Using: SERIAL
- Upload Speed: 115200
Problem Description
In my program, I am trying to reuse an HTTPClient to make a second connection to a different server. If the first server sends Connection: keep-alive, the HTTPClient attempts to reuse the connection when connecting to the new server, even though it's connecting to a new host.
It seems to me like begin or beginInternal should check if the new connection will be to the same host/port, and clear _canReuse otherwise. setURL does something like that, but it is only called when handling redirects.
You can work around this by calling setReuse(false), but I don't think that should be necessary to handle this use case.
The code below demonstrates this:
MCVE Sketch
// nb. This is a minimal bug reproduction and does not reflect best practices.
#include <Arduino.h> #include <ESP8266WiFi.h> #include <ESP8266HTTPClient.h>
#define WIFI_ESSID "xxx" #define WIFI_PASSWORD "xxx" #define EXT_IP_URL "https://ip.dzdz.cz" #define POST_URL "https://hookb.in/nPpMqzWewdtZ7Qrr7gYB"
WiFiClientSecure wifiClient;
void setup() { Serial.begin(115200);
Serial.printf_P(PSTR("%lu: Connecting to WiFi (%s)\r\n"), millis(), WIFI_ESSID);
WiFi.mode(WIFI_STA);
WiFi.begin(WIFI_ESSID, WIFI_PASSWORD);
yield();
Serial.printf_P(PSTR("%lu: Waiting for initial WiFi connection\r\n\t"), millis());
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.printf_P(PSTR("\n%lu: Connected. My IP: %s\r\n"), millis(), WiFi.localIP().toString().c_str());
// This is used to make this a minimal bug reproduction.
// This is not example code.
wifiClient.setInsecure(); // Do not copy this into your project.}
void loop() { HTTPClient httpClient; httpClient.begin(wifiClient, EXT_IP_URL); Serial.printf_P(PSTR("%lu: Starting GET request to %s\r\n"), millis(), EXT_IP_URL); int respCode = httpClient.GET(); String getResult = ""; if (respCode >= 400) { Serial.printf_P(PSTR("%lu: HTTP Error %d\r\n"), millis(), respCode); } else if (respCode > 0) { Serial.printf_P(PSTR("%lu: HTTP %d\r\n"), millis(), respCode); getResult = httpClient.getString(); Serial.printf_P(PSTR("\t%s\r\n"), getResult.c_str()); } else { Serial.printf_P(PSTR("%lu: error: %s\r\n"), millis(), HTTPClient::errorToString(respCode).c_str()); } httpClient.end();
// The first request, above, succeeds; the second request, below, will fail with HTTP 404. // httpClient.setReuse(false); // Uncommenting this line works around the bug
httpClient.begin(wifiClient, POST_URL);
Serial.printf_P(PSTR("%lu: Starting POST request to %s\r\n"), millis(), POST_URL);
respCode = httpClient.POST(getResult);
if (respCode >= 400) {
Serial.printf_P(PSTR("%lu: HTTP Error %d\r\n"), millis(), respCode);
} else if (respCode > 0) {
Serial.printf_P(PSTR("%lu: HTTP %d\r\n"), millis(), respCode);
} else {
Serial.printf_P(PSTR("%lu: error: %s\r\n"), millis(), HTTPClient::errorToString(respCode).c_str());
}
httpClient.end();}
Debug Messages
SDK:2.2.2-dev(38a443e)/Core:3.0.2=30002000/lwIP:STABLE-2_1_2_RELEASE/glue:1.2-48-g7421258/BearSSL:6105635
70: Connecting to WiFi (dzombak)
fpm close 1
mode : sta(ec:fa:bc:04:2c:9d)
add if0
76: Waiting for initial WiFi connection
.....scandone
state: 0 -> 2 (b0)
.state: 2 -> 3 (0)
state: 3 -> 5 (10)
add 0
aid 1
cnt
connected with dzombak, channel 1
dhcp client start...
ip:192.168.1.191,mask:255.255.255.0,gw:192.168.1.1
.
4302: Connected. My IP: 192.168.1.191
[HTTP-Client][begin] url: https://ip.dzdz.cz
[HTTP-Client][begin] host: ip.dzdz.cz port: 443 url:
4306: Starting GET request to https://ip.dzdz.cz
[HTTP-Client][sendRequest] type: 'GET' redirCount: 0
[HTTP-Client] connected to ip.dzdz.cz:443
[HTTP-Client] sending request header
-----
GET / HTTP/1.1
Host: ip.dzdz.cz
User-Agent: ESP8266HTTPClient
Accept-Encoding: identity;q=1,chunked;q=0.1,*;q=0
Connection: keep-alive
Content-Length: 0
-----
'HTTP-Client][handleHeaderResponse] RX: 'HTTP/1.1 200 OK
'HTTP-Client][handleHeaderResponse] RX: 'Server: nginx
'HTTP-Client][handleHeaderResponse] RX: 'Date: Fri, 08 Oct 2021 17:44:08 GMT
'HTTP-Client][handleHeaderResponse] RX: 'Content-Type: text/plain
'HTTP-Client][handleHeaderResponse] RX: 'Content-Length: 13
'HTTP-Client][handleHeaderResponse] RX: 'Connection: keep-alive
'HTTP-Client][handleHeaderResponse] RX: 'Strict-Transport-Security: max-age=15768000;
'HTTP-Client][handleHeaderResponse] RX: 'X-Frame-Options: DENY
'HTTP-Client][handleHeaderResponse] RX: 'X-Content-Type-Options: nosniff
'HTTP-Client][handleHeaderResponse] RX: '
[HTTP-Client][handleHeaderResponse] code: 200
[HTTP-Client][handleHeaderResponse] size: 13
5095: HTTP 200
[HTTP-Client][end] tcp keep open for reuse
73.145.176.71
[HTTP-Client][end] tcp keep open for reuse
[HTTP-Client][begin] url: https://hookb.in/nPpMqzWewdtZ7Qrr7gYB
[HTTP-Client][begin] host: hookb.in port: 443 url: /nPpMqzWewdtZ7Qrr7gYB
5117: Starting POST request to https://hookb.in/nPpMqzWewdtZ7Qrr7gYB
[HTTP-Client][sendRequest] type: 'POST' redirCount: 0
[HTTP-Client] connect: already connected, reusing connection
[HTTP-Client] sending request header
-----
POST /nPpMqzWewdtZ7Qrr7gYB HTTP/1.1
Host: hookb.in
User-Agent: ESP8266HTTPClient
Accept-Encoding: identity;q=1,chunked;q=0.1,*;q=0
Connection: keep-alive
Content-Length: 13
-----
'HTTP-Client][handleHeaderResponse] RX: 'HTTP/1.1 404 Not Found
'HTTP-Client][handleHeaderResponse] RX: 'Server: nginx
'HTTP-Client][handleHeaderResponse] RX: 'Date: Fri, 08 Oct 2021 17:44:08 GMT
'HTTP-Client][handleHeaderResponse] RX: 'Content-Type: text/html; charset=utf-8
'HTTP-Client][handleHeaderResponse] RX: 'Content-Length: 2833
'HTTP-Client][handleHeaderResponse] RX: 'Connection: keep-alive
'HTTP-Client][handleHeaderResponse] RX: 'Vary: Accept-Encoding
'HTTP-Client][handleHeaderResponse] RX: 'ETag: "61606e2a-b11"
'HTTP-Client][handleHeaderResponse] RX: '
[HTTP-Client][handleHeaderResponse] code: 404
[HTTP-Client][handleHeaderResponse] size: 2833
5330: HTTP Error 404
[HTTP-Client][end] still data in buffer (2833), clean up.
[HTTP-Client][end] tcp keep open for reuse