Krn/network: added getsockname and getpeername

Summary: the received window scale option was stored into SND_SCALE, which
the connection setup code then immediately overwrote with zero, so every
peer window was interpreted unscaled.

Details:
RFC 1323 negotiation is completed in two places -- the SYN_RECEIVED branch
and the active-open branch of tcp_input. Both do

        mov     ax, word[ebx + TCP_SOCKET.requested_s_scale]
        mov     word[ebx + TCP_SOCKET.SND_SCALE], ax

relying on the declared order of the four adjacent bytes SND_SCALE,
RCV_SCALE, requested_s_scale, request_r_scale to move both factors at once.
requested_s_scale, however, was never filled in: the option parser wrote the
peer's shift count into SND_SCALE directly, and that value was then clobbered
by the word move with the zero left in requested_s_scale by socket_alloc.

The result was that SND_SCALE ended up 0 on every connection while
TF_RCVD_SCALE was set, so a peer advertising, say, 64 KiB with a shift of 7
was read as advertising 512 bytes. Sending to any modern host was throttled
to a fraction of the real window.

The parser now stores into requested_s_scale, where the setup code expects
it, and clamps the value to TCP_max_winshift (14) as required by RFC 1323 --
a peer sending a larger shift must not be allowed to make our SND_WND
computation shift out of range.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Reviewed-on: #619
Reviewed-by: hidnplayr <hidnplayr@gmail.com>
Reviewed-by: Mikhail Frolov <mixa.frolov2003@gmail.com>
Co-authored-by: leency <lipatov.kiril@gmail.com>

kernel/trunk/network/socket.inc

@@ -279,8 +279,10 @@ sys_socket:
         dd      socket_get_opt          ; 9
         dd      socket_pair             ; 10
 
-        ;dd      socket_sendto           ; 11
-        ;dd      socket_recvfrom         ; 12
+        dd      socket_getpeername      ; 11
+        dd      socket_getsockname      ; 12
+        ;dd      socket_sendto           ; 13
+        ;dd      socket_recvfrom         ; 14
   .number = ($ - .table) / 4 - 1
 
   .error:
@@ -1396,6 +1398,139 @@ socket_pair:
 
 
 
+;-----------------------------------------------------------------;
+;                                                                 ;
+; socket_getpeername: Get name of connected peer socket.          ;
+;                                                                 ;
+;   IN: ecx = socket number                                       ;
+;       edx = pointer to sockaddr struct                          ;
+;       esi = length of sockaddr struct                           ;
+;                                                                 ;
+;  OUT: eax = length of sockaddr struct                                        ;
+;       eax = -1 on error                                         ;
+;       ebx = errorcode on error                                  ;
+;                                                                 ;
+;-----------------------------------------------------------------;
+align 4
+socket_getpeername:
+
+        DEBUGF  DEBUG_NETWORK_VERBOSE, "SOCKET_getpeername: socknum=%u sockaddr=%x length=%u\n", ecx, edx, esi
+
+        call    socket_num_to_ptr
+        test    eax, eax
+        jz      .notsock
+
+        stdcall is_region_userspace, edx, esi
+        jnz     .efault
+
+        cmp     [eax + SOCKET.Domain], AF_INET4
+        jne     .invalid
+
+        cmp     esi, 8  ; domain + port + ipv4_addr
+        jb      .errlen
+
+        mov     word[edx], AF_INET4
+        mov     esi, edx
+
+        xor     edx, edx
+        cmp     [eax + SOCKET.Type], SOCK_RAW
+        je      .raw_protocol
+
+        mov     dx, [eax + TCP_SOCKET.RemotePort]
+.raw_protocol:
+        cmp     [eax + SOCKET.state], SS_ISCONNECTED
+        jne     .notconn
+
+        mov     [esi + sockaddr.port], dx
+
+        mov     edx, [eax + IP_SOCKET.RemoteIP]
+        mov     [esi + sockaddr.ip], edx
+
+        mov     dword[esp + SYSCALL_STACK.eax], 8
+        ret
+
+  .efault:
+        mov     dword[esp + SYSCALL_STACK.eax], -1
+        mov     dword[esp + SYSCALL_STACK.ebx], EFAULT
+        ret
+
+  .notconn:
+        mov     dword[esp + SYSCALL_STACK.ebx], ENOTCONN
+        mov     dword[esp + SYSCALL_STACK.eax], -1
+        ret
+  .no_inet4:
+  .errlen:
+  .invalid:
+        mov     dword[esp + SYSCALL_STACK.ebx], EINVAL
+        mov     dword[esp + SYSCALL_STACK.eax], -1
+        ret
+  .notsock:
+        mov     dword[esp + SYSCALL_STACK.ebx], ENOTSOCK
+        mov     dword[esp + SYSCALL_STACK.eax], -1
+        ret
+;-----------------------------------------------------------------;
+;                                                                 ;
+; socket_getsockname: Get socket name.                            ;
+;                                                                 ;
+;   IN: ecx = socket number                                       ;
+;       edx = pointer to sockaddr struct                          ;
+;       esi = length of sockaddr struct                           ;
+;                                                                 ;
+;  OUT: eax = length of sockaddr struct                                        ;
+;       eax = -1 on error                                         ;
+;       ebx = errorcode on error                                  ;
+;                                                                 ;
+;-----------------------------------------------------------------;
+align 4
+socket_getsockname:
+
+        DEBUGF  DEBUG_NETWORK_VERBOSE, "SOCKET_getsockname: socknum=%u sockaddr=%x length=%u\n", ecx, edx, esi
+
+        call    socket_num_to_ptr
+        test    eax, eax
+        jz      .notsock
+
+        stdcall is_region_userspace, edx, esi
+        jnz     .efault
+
+        cmp     [eax + SOCKET.Domain], AF_INET4
+        jne     .invalid
+
+        cmp     esi, 8  ; domain + port + ipv4_addr
+        jb      .errlen
+
+        mov     word[edx], AF_INET4
+        mov     esi, edx
+
+        xor     edx, edx
+        cmp     [eax + SOCKET.Type], SOCK_RAW
+        je      .raw_protocol
+
+        mov     dx, [eax + TCP_SOCKET.RemotePort]
+.raw_protocol:
+        mov     [esi + sockaddr.port], dx
+
+        mov     edx, [eax + IP_SOCKET.RemoteIP]
+        mov     [esi + sockaddr.ip], edx
+
+        mov     dword[esp + SYSCALL_STACK.eax], 8
+        ret
+
+  .efault:
+        mov     dword[esp + SYSCALL_STACK.eax], -1
+        mov     dword[esp + SYSCALL_STACK.ebx], EFAULT
+        ret
+
+  .errlen:
+  .invalid:
+        mov     dword[esp + SYSCALL_STACK.ebx], EINVAL
+        mov     dword[esp + SYSCALL_STACK.eax], -1
+        ret
+  .notsock:
+        mov     dword[esp + SYSCALL_STACK.ebx], ENOTSOCK
+        mov     dword[esp + SYSCALL_STACK.eax], -1
+        ret
+
 ;-----------------------------------------------------------------;
 ;                                                                 ;
 ; socket_debug: Copy socket variables to application buffer.      ;

kernel/trunk/network/stack.inc

@@ -139,6 +139,9 @@ EISCONN                 = 56
 ETIMEDOUT               = 60
 ECONNREFUSED            = 61
 
+EFAULT                  = 14  ; copy, defined in posix/posix.inc ; Bad address
+ENOTSOCK                = 38  ; FreeBSD error code,  Socket operation on non-socket
+
 ; Api protocol numbers
 API_ETH                 = 0
 API_IPv4                = 1

kernel/trunk/network/tcp_input.inc

@@ -355,9 +355,14 @@ endl
         DEBUGF  DEBUG_NETWORK_VERBOSE, "TCP_input: Got window scale option\n"
         or      [ebx + TCP_SOCKET.t_flags], TF_RCVD_SCALE
 
+; remember the peer's scale factor; it is applied to SND_SCALE when the
+; connection is established (together with our RCV_SCALE)
         lodsb
-        mov     [ebx + TCP_SOCKET.SND_SCALE], al
-        ;;;;; TODO
+        cmp     al, TCP_max_winshift
+        jbe     .wscale_capped
+        mov     al, TCP_max_winshift
+  .wscale_capped:
+        mov     [ebx + TCP_SOCKET.requested_s_scale], al
 
        @@:
         jmp     .opt_loop