arduino/esp8266
1
0
Fork 0
mirror of https://github.com/esp8266/Arduino.git synced 2025-06-12 01:53:07 +03:00
Code Activity

lwIP-v2: new patch to randomize tcp source ports (#5906)

Browse Source 
ref: d-a-v/esp82xx-nonos-linklayer#31
origin: #5902
me-no-dev/ESPAsyncTCP#108

Following the links above is instructive.
To summarize:

    * currently and from a long time lwIP tcp client connections always uses the same tcp source port number right after boot
    * this port number is increased everytime a new one is needed (= new tcp client connection)
      (to be noted, linux has the same increasing behavior)
    * when connecting to the same server (right after boot), the triplet (esp-ip-address, source port, destination port) are the same, and may hit remote server list of sockets in time-wait-state (previous connection unproperly closed from the same esp). Consequently the new connection fails when it happens.
    * this is happening only when debugging (esp reboots often, in less time than time-wait expiration), so the nasty effect is amplified especially when bugs are being chased
    * efforts had been done when espressif's lwIP implementation wasn't open source, with WiFiClient::setLocalPortStart() #632 but it must be explicitely called with a different random number at every reboot. Efficient but not ideal.

This PR uses espressif firmware's r_rand() everytime a new local source port is needed. A different source port number is now showed by tcpdump right after boot. Source port range and duplication is verified everytime in lwIP's src/core/tcp.c:tcp_new_port(). It is implemented as a local patch for upstream lwIP so it is valid not only with WiFiClient but also with @me-no-dev's Async libraries (they don't use WiFiClient).

WiFiClient::setLocalPortStart() is still usable with the same effects as before.
This commit is contained in:
david gauchard
2019-04-05 17:26:51 +02:00
committed by GitHub
parent 9a2ed274f3
commit a1796f455a
8 changed files with 18 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
tools/sdk/lwip2/include/gluedebug.h
View File

@ -18,7 +18,11 @@
#define ULWIPDEBUG 0 // 0 or 1 (trigger lwip debug)
#define ULWIPASSERT 0 // 0 or 1 (trigger lwip self-check, 0 saves flash)
#if ARDUINO
#define STRING_IN_FLASH 1 // *print("fmt is stored in flash")
#else
#define STRING_IN_FLASH 0 // *print("fmt is stored in flash")
#endif
#define ROTBUFLEN_BIT 11 // (UDEBUGSTORE=1) doprint()'s buffer: 11=2048B
@ -39,7 +43,9 @@ extern "C"
void (*phy_capture) (int netif_idx, const char* data, size_t len, int out, int success);
/////////////////////////////////////////////////////////////////////////////
#if ARDUINO
#include <sys/pgmspace.h>
#endif
#if UDEBUG && UDEBUGSTORE
#warning use 'doprint_allow=1' right after Serial is enabled
@ -94,6 +100,7 @@ int doprint_minus (const char* format, ...) __attribute__ ((format (printf, 1, 2
#define uprint(x...) do { (void)0; } while (0)
#endif
#if ARDUINO
#define udoassert(assertion...) \
do { if ((assertion) == 0) { \
static const char assrt[] ICACHE_RODATA_ATTR STORE_ATTR = #assertion " wrong@"; \
@ -104,6 +111,9 @@ do { if ((assertion) == 0) { \
os_printf_plus(assrt_line, __LINE__); \
uhalt(); \
} } while (0)
#else
#define udoassert(assertion...) do { if ((assertion) == 0) { os_printf("assert fail: " #assertion " @%s:%d\n", __FILE__, __LINE__); uhalt(); } } while (0)
#endif
#if UNDEBUG
#define uassert(assertion...) do { (void)0; } while (0)