From c4dc80498b7e40abc6edac6c29a8842a396b3b1c Mon Sep 17 00:00:00 2001
From: ruti <>
Date: Mon, 3 Jul 2023 19:59:39 +0200
Subject: [PATCH] set ttl and EAGAIN handler

---
 conev.c  | 16 ++++++++--
 conev.h  |  4 ++-
 desync.c | 57 +++++++++++++++++++++++-----------
 main.c   |  3 --
 params.h |  1 -
 proxy.c  | 94 +++++++++++++++++++++-----------------------------------
 6 files changed, 91 insertions(+), 84 deletions(-)

diff --git a/conev.c b/conev.c
index fdc05cb..3cfceb9 100644
--- a/conev.c
+++ b/conev.c
@@ -51,7 +51,9 @@ struct eval *add_event(struct poolhd *pool, enum eid type,
     val->index = pool->count;
     val->type = type;
     val->pair = 0;
-    val->send_count = 0;
+    val->tmpbuf = 0;
+    val->size = 0;
+    val->offset = 0;
     val->flag = 0;
     
     #ifndef NOEPOLL
@@ -80,6 +82,10 @@ void del_event(struct poolhd *pool, struct eval *val)
     if (!val->fd) {
         return;
     }
+    if (val->tmpbuf) {
+        free(val->tmpbuf);
+        val->tmpbuf = 0;
+    }
     close(val->fd);
     val->fd = 0;
     pool->count--;
@@ -106,7 +112,13 @@ void destroy_pool(struct poolhd *pool)
 {
     for (int x = 0; x < pool->count; x++) {
         struct eval *val = pool->links[x];
-        if (val->fd) close(val->fd);
+        if (val->fd) {
+            close(val->fd);
+        }
+        if (val->tmpbuf) {
+            free(val->tmpbuf);
+            val->tmpbuf = 0;
+        }
     }
     if (pool->items) {
         free(pool->items);
diff --git a/conev.h b/conev.h
index 726c86e..adf1144 100644
--- a/conev.h
+++ b/conev.h
@@ -48,7 +48,9 @@ struct eval {
     int index;
     enum eid type;
     struct eval *pair;
-    size_t send_count;
+    char *tmpbuf;
+    ssize_t size;
+    int offset;
     int flag;
     #ifndef NOEPOLL
     uint32_t events;
diff --git a/desync.c b/desync.c
index a966791..3196a4e 100644
--- a/desync.c
+++ b/desync.c
@@ -10,9 +10,10 @@
 
 #ifdef __linux__
 #include <sys/sendfile.h>
+#define _sendfile(outfd, infd, start, len) sendfile(outfd, infd, start, len)
 #else
 #include <sys/uio.h>
-#define sendfile(outfd, infd, start, len) sendfile(infd, outfd, start, len, 0, 0)
+#define _sendfile(outfd, infd, start, len) sendfile(infd, outfd, start, len, 0, 0)
 #endif
 
 #ifdef MFD_CLOEXEC
@@ -26,7 +27,25 @@
 #include <packets.h>
 
 
-int fake_attack(int sfd, char *buffer, ssize_t n, int cnt, int pos)
+int setttl(int fd, int ttl, int family) {
+    int _ttl = ttl;
+    if (family == AF_INET) {
+        if (setsockopt(fd, IPPROTO_IP, IP_TTL,
+                 &_ttl, sizeof(_ttl)) < 0) {
+            perror("setsockopt IP_TTL");
+            return -1;
+        }
+    }
+    else if (setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
+             &_ttl, sizeof(_ttl)) < 0) {
+        perror("setsockopt IPV6_UNICAST_HOPS");
+        return -1;
+    }
+    return 0;
+}
+
+
+int fake_attack(int sfd, char *buffer, ssize_t n, int cnt, int pos, int fa)
 {
     struct packet pkt = cnt != IS_HTTP ? fake_tls : fake_http;
     size_t psz = pkt.size;
@@ -51,12 +70,10 @@ int fake_attack(int sfd, char *buffer, ssize_t n, int cnt, int pos)
         }
         memcpy(p, pkt.data, psz < pos ? psz : pos);
         
-        if (setsockopt(sfd, IPPROTO_IP, IP_TTL,
-                 &params.ttl, sizeof(params.ttl)) < 0) {
-            perror("setsockopt IP_TTL");
+        if (setttl(sfd, params.ttl, fa) < 0) {
             break;
         }
-        if (sendfile(sfd, ffd, 0, pos) < 0) {
+        if (_sendfile(sfd, ffd, 0, pos) < 0) {
             perror("sendfile");
             break;
         }
@@ -66,9 +83,7 @@ int fake_attack(int sfd, char *buffer, ssize_t n, int cnt, int pos)
         nanosleep(&delay, 0);
         memcpy(p, buffer, pos);
         
-        if (setsockopt(sfd, IPPROTO_IP, IP_TTL,
-                 &params.def_ttl, sizeof(int)) < 0) {
-            perror("setsockopt IP_TTL");
+        if (setttl(sfd, params.def_ttl, fa) < 0) {
             break;
         }
         if (send(sfd, buffer + pos, n - pos, 0) < 0) {
@@ -83,21 +98,17 @@ int fake_attack(int sfd, char *buffer, ssize_t n, int cnt, int pos)
 }
 
 
-int disorder_attack(int sfd, char *buffer, ssize_t n, int pos)
+int disorder_attack(int sfd, char *buffer, ssize_t n, int pos, int fa)
 {
     int bttl = 1;
-    if (setsockopt(sfd, IPPROTO_IP, IP_TTL,
-             (char *)&bttl, sizeof(bttl)) < 0) {
-        perror("setsockopt IP_TTL");
+    if (setttl(sfd, bttl, fa) < 0) {
         return -1;
     }
     if (send(sfd, buffer, pos, 0) < 0) {
         perror("send");
         return -1;
     }
-    if (setsockopt(sfd, IPPROTO_IP, IP_TTL,
-            (char *)&params.def_ttl, sizeof(int)) < 0) {
-        perror("setsockopt IP_TTL");
+    if (setttl(sfd, params.def_ttl, fa) < 0) {
         return -1;
     }
     if (send(sfd, buffer + pos, n - pos, 0) < 0) {
@@ -114,6 +125,15 @@ int desync(int sfd, char *buffer, ssize_t n)
     char *host = 0;
     int len = 0, type = 0;
     
+    struct sockaddr sa;
+    socklen_t alen = sizeof(sa);
+    
+    if (getsockname(sfd, &sa, &alen)) {
+        perror("getsockname");
+        return -1;
+    }
+    int fa = sa.sa_family;
+    
     if ((len = parse_tls(buffer, n, &host))) {
         type = IS_HTTPS;
     }
@@ -146,10 +166,11 @@ int desync(int sfd, char *buffer, ssize_t n)
     }
     else switch (params.attack) {
         case DESYNC_FAKE:
-            return fake_attack(sfd, buffer, n, type, pos);
+            return fake_attack(sfd, buffer, n, type, pos, fa);
             
         case DESYNC_DISORDER:
-            return disorder_attack(sfd, buffer, n, pos);
+            printf("disorder attack\n");
+            return disorder_attack(sfd, buffer, n, pos, fa);
         
         case DESYNC_SPLIT:
         default:
diff --git a/main.c b/main.c
index 0c941d7..3bd567f 100644
--- a/main.c
+++ b/main.c
@@ -40,7 +40,6 @@ struct params params = {
     
     .bfsize = 16384,
     .send_bfsz = 65536,
-    .nack_max = 65536 * 2 - 16384,
     .debug = 0
 };
 
@@ -369,8 +368,6 @@ int main(int argc, char **argv)
     if (params.send_bfsz * 2 <= params.bfsize) {
         fprintf(stderr, "send buffer too small\n");
         return -1;
-    } else {
-        params.nack_max = val * 2 - params.bfsize;
     }
     FILE *file;
     if (pidfile) {
diff --git a/params.h b/params.h
index 6f86985..3130d33 100644
--- a/params.h
+++ b/params.h
@@ -30,7 +30,6 @@ struct params {
     
     int debug;
     size_t bfsize;
-    size_t nack_max;
     int send_bfsz;
 };
 
diff --git a/proxy.c b/proxy.c
index 486e1c0..91a3962 100644
--- a/proxy.c
+++ b/proxy.c
@@ -283,24 +283,6 @@ int handle_http(int fd, char *buffer,
 }
 
 
-int nsendc(int fd, int *wn)
-{
-    #ifdef SO_NWRITE
-    socklen_t len = sizeof(*wn);
-    if (getsockopt(fd, SOL_SOCKET, SO_NWRITE, wn, &len) < 0) {
-        perror("getsockopt SO_NWRITE");
-        return -1;
-    }
-    #else
-    if (ioctl(fd, TIOCOUTQ, wn) < 0 ) {
-        perror("ioctl");
-        return -1;
-    }
-    #endif
-    return 0;
-}
-
-
 static inline int create_conn(struct poolhd *pool, struct eval *val,
         enum eid nxt, struct sockaddr_ina *dst)
 {
@@ -519,12 +501,10 @@ static inline int on_tunnel(struct poolhd *pool, struct eval *val,
         char *buffer, size_t bfsize, int out)
 {
     ssize_t n = 0;
-    int peek = 0;
+    char *rb = buffer;
     struct eval *pair = val->pair;
     
-    if (val->flag & FLAG_NOSEND && out) {
-        val->flag &= ~FLAG_NOSEND;
-        
+    if (pair->tmpbuf && out) {
         mod_etype(pool, val, POLLOUT, 0);
         mod_etype(pool, val->pair, POLLIN, 1);
         
@@ -532,48 +512,45 @@ static inline int on_tunnel(struct poolhd *pool, struct eval *val,
         val = val->pair;
     }
     do {
-        if (pair->send_count >= params.nack_max) {
-            int wn = 0;
-            if (nsendc(pair->fd, &wn)) {
+        if (val->tmpbuf) {
+            n = val->size - val->offset;
+            rb = val->tmpbuf + val->offset;
+        } else {
+            n = recv(val->fd, buffer, bfsize, 0);
+            if (n < 0 && errno == EAGAIN)
+                break;
+            if (n < 1) {
+                if (n) perror("recv server");
                 return -1;
             }
-            pair->send_count = wn;
-            if (wn) {
-                LOG(LOG_S, "not ack: %d (fd: %d)\n", wn, pair->fd);
-            }
-            if (wn >= params.nack_max) {
-                peek = MSG_PEEK;
-            }
         }
-        n = recv(val->fd, buffer, bfsize, peek);
-        
-        if (n < 0 && errno == EAGAIN)
-            break;
-        if (n < 1) {
-            if (n) perror("recv server");
-            return -1;
-        }
-        if (send(pair->fd, buffer, n, 0) < 0) {
-            if (errno == EAGAIN && peek) {
-                LOG(LOG_S, "EAGAIN, set POLLOUT (fd: %d)\n", pair->fd);
-                
-                mod_etype(pool, val, POLLIN, 0);
-                mod_etype(pool, pair, POLLOUT, 1);
-                
-                pair->flag |= FLAG_NOSEND;
+        ssize_t sn = send(pair->fd, rb, n, 0);
+        if (sn != n) {
+            if (sn < 0 && errno != EAGAIN) {
+                perror("send");
+                return -1;
+            }
+            LOG(LOG_S, "EAGAIN, set POLLOUT (fd: %d)\n", pair->fd);
+            mod_etype(pool, val, POLLIN, 0);
+            mod_etype(pool, pair, POLLOUT, 1);
+            
+            if (val->tmpbuf) {
+                LOG(LOG_S, "EAGAIN, AGAIN ! (fd: %d)\n", pair->fd);
+                if (sn > 0)
+                    val->offset += sn;
                 break;
             }
-            perror("send");
-            return -1;
+            val->size = sn > 0 ? n - sn : n;
+            val->tmpbuf = malloc(val->size);
+            memcpy(val->tmpbuf, buffer + (sn > 0 ? sn : 0), val->size);
+            break;
         }
-        if (peek) {
-            if (recv(val->fd, buffer, n, 0) != n) {
-                perror("recv");
-                return -1;
-            }
+        else if (val->tmpbuf) {
+            free(val->tmpbuf);
+            val->tmpbuf = 0;
+            rb = buffer;
+            continue;
         }
-        pair->send_count += n;
-        
     } while (n == bfsize);
     return 0;
 }
@@ -624,8 +601,7 @@ int big_loop(int srvfd)
                 continue;
         
             case EV_TUNNEL:
-                if ((etype & POLLHUP) || 
-                        on_tunnel(pool, val, buffer, bfsize, etype & POLLOUT))
+                if (on_tunnel(pool, val, buffer, bfsize, etype & POLLOUT))
                     del_event(pool, val);
                 continue;