From a067afe6e418180da1dc5f336f3420eddb82a39b Mon Sep 17 00:00:00 2001
From: ruti <>
Date: Wed, 16 Oct 2024 12:54:27 +0300
Subject: [PATCH] Restore offset in splited request

---
 conev.h  | 13 +++++++------
 desync.c | 34 ++++++++++++++++------------------
 extend.c |  5 ++++-
 main.c   |  3 ++-
 params.h |  1 +
 proxy.c  |  6 +++---
 6 files changed, 33 insertions(+), 29 deletions(-)

diff --git a/conev.h b/conev.h
index a3823ac..598cdd0 100644
--- a/conev.h
+++ b/conev.h
@@ -2,6 +2,7 @@
 #define CONEV_H
 
 #include <stdint.h>
+#include <stdbool.h>
 
 #ifndef __linux__
     #define NOEPOLL
@@ -56,10 +57,10 @@ char *eid_name[] = {
 #endif
 
 struct buffer {
-    ssize_t size;
-    int offset;
+    size_t size;
+    unsigned int offset;
     char *data;
-    char locked;
+    bool locked;
 };
 
 struct eval {
@@ -75,11 +76,11 @@ struct eval {
         struct sockaddr_in6 in6;
     };
     ssize_t recv_count;
+    ssize_t round_sent;
     unsigned int round_count;
-    char last_round;
     int attempt;
-    char cache;
-    char mark; //
+    bool cache;
+    bool mark; //
 };
 
 struct poolhd {
diff --git a/desync.c b/desync.c
index feae490..7eac3f6 100644
--- a/desync.c
+++ b/desync.c
@@ -434,19 +434,19 @@ ssize_t desync(int sfd, char *buffer, size_t bfsize,
     char *host = 0;
     int len = 0, type = 0, host_pos = 0;
     
-    // parse packet
-    if ((len = parse_tls(buffer, n, &host))) {
-        type = IS_HTTPS;
+    if (offset == 0) {
+        if ((len = parse_tls(buffer, n, &host))) {
+            type = IS_HTTPS;
+        }
+        else if ((len = parse_http(buffer, n, &host, 0))) {
+            type = IS_HTTP;
+        }
+        if (len && host) {
+            LOG(LOG_S, "host: %.*s (%zd)\n",
+                len, host, host - buffer);
+            host_pos = host - buffer;
+        }
     }
-    else if ((len = parse_http(buffer, n, &host, 0))) {
-        type = IS_HTTP;
-    }
-    if (len && host) {
-        LOG(LOG_S, "host: %.*s (%zd)\n",
-            len, host, host - buffer);
-        host_pos = host - buffer;
-    }
-    
     // modify packet
     if (type == IS_HTTP && dp.mod_http) {
         LOG(LOG_S, "modify HTTP: n=%zd\n", n);
@@ -484,9 +484,8 @@ ssize_t desync(int sfd, char *buffer, size_t bfsize,
             lp = pos + 5;
         }
     }
-    // desync
     #ifdef __linux__
-    if (dp.drop_sack && drop_sack(sfd)) {
+    if (!offset && dp.drop_sack && drop_sack(sfd)) {
         return -1;
     }
     #endif
@@ -504,15 +503,14 @@ ssize_t desync(int sfd, char *buffer, size_t bfsize,
             
         pos += part.s * (part.r - r);
         
-        // after EAGAIN
-        if (offset && pos <= offset) {
+        if (!(part.flag & OFFSET_START) && offset && pos <= offset) {
             continue;
         }
-        else if (pos < 0 || pos > n || pos < lp) {
+        if (pos < 0 || pos > n || pos < lp) {
             LOG(LOG_E, "split cancel: pos=%ld-%ld, n=%zd\n", lp, pos, n);
             break;
         }
-        // send part
+        
         ssize_t s = 0;
         switch (part.m) {
             #ifdef FAKE_SUPPORT
diff --git a/extend.c b/extend.c
index 2e4c727..a642e92 100644
--- a/extend.c
+++ b/extend.c
@@ -367,8 +367,11 @@ ssize_t tcp_send_hook(struct poolhd *pool, struct eval *remote,
     int m = client->attempt;
     LOG((m ? LOG_S : LOG_L), "desync params index: %d\n", m);
     
+    ssize_t offset = client->round_sent + client->buff.offset;
+    if (!offset && remote->round_count) offset = -1;
+    
     sn = desync(remote->fd, buffer, bfsize, n,
-        0, (struct sockaddr *)&remote->in6, m);
+        offset, (struct sockaddr *)&remote->in6, m);
     return sn;
 }
 
diff --git a/main.c b/main.c
index 03c1c18..3a8bb90 100644
--- a/main.c
+++ b/main.c
@@ -421,7 +421,8 @@ int parse_offset(struct part *part, const char *str)
             case 'r':
                 part->flag |= OFFSET_RAND;
                 break;
-            case 's':;
+            case 's':
+                part->flag |= OFFSET_START;
         }
     }
     part->pos = val;
diff --git a/params.h b/params.h
index 3609ed0..1fdade9 100644
--- a/params.h
+++ b/params.h
@@ -26,6 +26,7 @@
 #define OFFSET_RAND 4
 #define OFFSET_SNI 8
 #define OFFSET_HOST 16
+#define OFFSET_START 32
 
 #define DETECT_HTTP_LOCAT 1
 #define DETECT_TLS_ERR 2
diff --git a/proxy.c b/proxy.c
index fd6c7e4..c61ce50 100644
--- a/proxy.c
+++ b/proxy.c
@@ -686,13 +686,13 @@ int on_tunnel(struct poolhd *pool, struct eval *val,
             return -1;
         }
         val->recv_count += n;
-        if (!val->last_round) {
+        if (val->round_sent == 0) {
             val->round_count++;
-            val->last_round = 1;
-            pair->last_round = 0;
+            pair->round_sent = 0;
         }
         
         ssize_t sn = tcp_send_hook(pool, pair, buffer, bfsize, n);
+        val->round_sent += sn > 0 ? sn : 0;
         if (sn < n) {
             if (sn < 0) {
                 uniperror("send");