| 0,0 → 1,1371 |
|---|
| ;----------------------------------------------------------------- |
| ; |
| ; TCP_input: |
| ; |
| ; IN: [esp] = ptr to buffer |
| ; [esp+4] = buffer size |
| ; ebx = ptr to device struct |
| ; ecx = segment size |
| ; edx = ptr to TCP segment |
| ; |
| ; esi = ipv4 source address |
| ; edi = ipv4 dest address |
| ; |
| ; OUT: / |
| ; |
| ;----------------------------------------------------------------- |
| align 4 |
| TCP_input: |
| |
| DEBUGF 1,"TCP_input size=%u ", ecx |
| ; Offset must be greater than or equal to the size of the standard TCP header (20) and less than or equal to the TCP length. |
| |
| movzx eax, [edx + TCP_segment.DataOffset] |
| and eax, 0xf0 |
| shr al, 2 |
| |
| DEBUGF 1,"headersize=%u\n", eax |
| |
| cmp eax, 20 |
| jl .drop_not_locked |
| |
| ;------------------------------- |
| ; Now, re-calculate the checksum |
| |
| push eax ecx edx |
| pushw [edx + TCP_segment.Checksum] |
| mov [edx + TCP_segment.Checksum], 0 |
| push esi edi |
| mov esi, edx |
| TCP_checksum (esp), (esp+4) |
| pop esi edi ; yes, swap them (we dont need dest addr) |
| pop cx ; previous checksum |
| cmp cx, dx |
| pop edx ecx esi |
| jnz .drop_not_locked |
| |
| DEBUGF 1,"Checksum is correct\n" |
| |
| sub ecx, esi ; update packet size |
| jl .drop_not_locked |
| DEBUGF 1,"we got %u bytes of data\n", ecx |
| |
| ;----------------------------------------------------------------------------------------- |
| ; Check if this packet has a timestamp option (We do it here so we can process it quickly) |
| |
| cmp esi, 20 + 12 ; Timestamp option is 12 bytes |
| jl .no_timestamp |
| je .is_ok |
| |
| cmp byte [edx + TCP_segment.Data + 12], TCP_OPT_EOL ; end of option list |
| jne .no_timestamp |
| |
| .is_ok: |
| test [edx + TCP_segment.Flags], TH_SYN ; SYN flag must not be set |
| jnz .no_timestamp |
| |
| cmp dword [edx + TCP_segment.Data], 0x0101080a ; Timestamp header |
| jne .no_timestamp |
| |
| DEBUGF 1,"timestamp ok\n" |
| |
| ; TODO: Parse the option |
| ; TODO: Set a Bit in the TCP to tell all options are parsed |
| |
| .no_timestamp: |
| |
| ;------------------------------------------- |
| ; Convert Big-endian values to little endian |
| |
| ntohd [edx + TCP_segment.SequenceNumber] |
| ntohd [edx + TCP_segment.AckNumber] |
| |
| ntohw [edx + TCP_segment.Window] |
| ntohw [edx + TCP_segment.UrgentPointer] |
| ntohw [edx + TCP_segment.SourcePort] |
| ntohw [edx + TCP_segment.DestinationPort] |
| |
| ;------------------------------------------------------------ |
| ; Next thing to do is find the TCB (thus, the socket pointer) |
| |
| ; IP Packet TCP Destination Port = local Port |
| ; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0) |
| ; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0) |
| |
| mov ebx, net_sockets |
| |
| .socket_loop: |
| mov ebx, [ebx + SOCKET.NextPtr] |
| or ebx, ebx |
| jz .drop_with_reset_not_locked |
| |
| cmp [ebx + SOCKET.Domain], AF_INET4 |
| jne .socket_loop |
| |
| cmp [ebx + SOCKET.Protocol], IP_PROTO_TCP |
| jne .socket_loop |
| |
| mov ax, [edx + TCP_segment.DestinationPort] |
| cmp [ebx + TCP_SOCKET.LocalPort], ax |
| jne .socket_loop |
| |
| mov eax, [ebx + IP_SOCKET.RemoteIP] |
| cmp eax, edi ; edi is source ip from packet |
| je @f |
| test eax, eax |
| jnz .socket_loop |
| @@: |
| |
| mov ax, [ebx + TCP_SOCKET.RemotePort] |
| cmp [edx + TCP_segment.SourcePort] , ax |
| je .found_socket |
| test ax, ax |
| jnz .socket_loop |
| .found_socket: |
| DEBUGF 1,"Socket ptr: %x\n", ebx |
| |
| ; ebx now contains the pointer to the socket |
| |
| ;---------------------------- |
| ; Check if socket isnt closed |
| |
| cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSED |
| je .drop_not_locked |
| |
| ;---------------- |
| ; Lock the socket |
| |
| add ebx, SOCKET.lock |
| DEBUGF 1,"lock: %x\n", [ebx] |
| call wait_mutex |
| sub ebx, SOCKET.lock |
| |
| DEBUGF 1,"Socket locked\n" |
| |
| ;--------------------------------------- |
| ; unscale the window into a 32 bit value |
| |
| movzx eax, [edx + TCP_segment.Window] |
| push ecx |
| mov cl, [ebx + TCP_SOCKET.SND_SCALE] |
| shl eax, cl |
| mov dword [edx + TCP_segment.Window], eax ; word after window is checksum, we dont need checksum anymore |
| pop ecx |
| |
| ;----------------------------------- |
| ; Is this socket a listening socket? |
| |
| test [ebx + SOCKET.options], SO_ACCEPTCON |
| jz .no_listening_socket |
| |
| call SOCKET_fork |
| jz .drop |
| |
| push [edx + TCP_segment.DestinationPort] |
| pop [eax + TCP_SOCKET.LocalPort] |
| |
| push [edx - IPv4_Packet.DataOrOptional + IPv4_Packet.DestinationAddress] ;;; FIXME |
| pop [eax + IP_SOCKET.LocalIP] |
| |
| push [edx - IPv4_Packet.DataOrOptional + IPv4_Packet.SourceAddress] ;;; FIXME |
| pop [eax + IP_SOCKET.RemoteIP] |
| |
| mov [eax + TCP_SOCKET.t_state], TCB_LISTEN |
| |
| jmp .not_uni_xfer |
| |
| .no_listening_socket: |
| |
| ;------------------------------------- |
| ; Reset idle timer and keepalive timer |
| |
| mov [ebx + TCP_SOCKET.t_idle], 0 |
| mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval |
| |
| ;-------------------- |
| ; Process TCP options |
| |
| cmp esi, 20 ; esi is headersize |
| je .no_options |
| |
| DEBUGF 1,"Segment has options\n" |
| |
| cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN ; no options when in listen state |
| jz .not_uni_xfer ; also no header prediction |
| |
| lea edi, [edx + TCP_segment.Data] |
| lea eax, [edx + esi] |
| |
| .opt_loop: |
| cmp edi, eax |
| jge .no_options |
| |
| cmp byte [edi], TCP_OPT_EOL ; end of option list? |
| jz .no_options |
| |
| cmp byte [edi], TCP_OPT_NOP ; nop ? |
| jz .opt_nop |
| |
| cmp byte [edi], TCP_OPT_MAXSEG |
| je .opt_maxseg |
| |
| cmp byte [edi], TCP_OPT_WINDOW |
| je .opt_window |
| |
| cmp byte [edi], TCP_OPT_TIMESTAMP |
| je .opt_timestamp |
| |
| jmp .no_options ; If we reach here, some unknown options were received, skip them all! |
| |
| .opt_nop: |
| inc edi |
| jmp .opt_loop |
| |
| .opt_maxseg: |
| cmp byte [edi+1], 4 |
| jne .no_options ; error occured, ignore all options! |
| |
| test [edx + TCP_segment.Flags], TH_SYN |
| jz @f |
| |
| movzx eax, word[edi+2] |
| rol ax, 8 |
| DEBUGF 1,"Maxseg: %u\n", ax |
| |
| mov [ebx + TCP_SOCKET.t_maxseg], eax |
| |
| @@: |
| add edi, 4 |
| jmp .opt_loop |
| |
| |
| .opt_window: |
| cmp byte [edi+1], 3 |
| jne .no_options |
| |
| test [edx + TCP_segment.Flags], TH_SYN |
| jz @f |
| |
| DEBUGF 1,"Got window option\n" |
| |
| ;;;;; |
| @@: |
| add edi, 3 |
| jmp .opt_loop |
| |
| |
| .opt_timestamp: |
| cmp byte [edi+1], 10 |
| jne .no_options |
| |
| DEBUGF 1,"Got timestamp option\n" |
| |
| ;;;;; |
| |
| add edi, 10 |
| jmp .opt_loop |
| |
| .no_options: |
| |
| |
| |
| |
| |
| |
| ;----------------------------------------------------------------------- |
| ; Time to do some header prediction (Original Principle by Van Jacobson) |
| |
| ; There are two common cases for an uni-directional data transfer. |
| ; |
| ; General rule: the packets has no control flags, is in-sequence, |
| ; window width didnt change and we're not retransmitting. |
| ; |
| ; Second rules: |
| ; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer. |
| ; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer |
| ; |
| ; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer. |
| ; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK |
| |
| cmp [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED |
| jnz .not_uni_xfer |
| |
| test [edx + TCP_segment.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG |
| jnz .not_uni_xfer |
| |
| test [edx + TCP_segment.Flags], TH_ACK |
| jz .not_uni_xfer |
| |
| mov eax, [edx + TCP_segment.SequenceNumber] |
| cmp eax, [ebx + TCP_SOCKET.RCV_NXT] |
| jne .not_uni_xfer |
| |
| mov eax, dword [edx + TCP_segment.Window] |
| cmp eax, [ebx + TCP_SOCKET.SND_WND] |
| jne .not_uni_xfer |
| |
| mov eax, [ebx + TCP_SOCKET.SND_NXT] |
| cmp eax, [ebx + TCP_SOCKET.SND_MAX] |
| jne .not_uni_xfer |
| |
| ;--------------------------------------- |
| ; check if we are sender in the uni-xfer |
| |
| ; If the following 4 conditions are all true, this segment is a pure ACK. |
| ; |
| ; - The segment contains no data. |
| test ecx, ecx |
| jnz .not_sender |
| |
| ; - The congestion window is greater than or equal to the current send window. |
| ; This test is true only if the window is fully open, that is, the connection is not in the middle of slow start or congestion avoidance. |
| mov eax, [ebx + TCP_SOCKET.SND_CWND] |
| cmp eax, [ebx + TCP_SOCKET.SND_WND] |
| jl .not_uni_xfer |
| |
| ; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent. |
| mov eax, [edx + TCP_segment.AckNumber] |
| cmp eax, [ebx + TCP_SOCKET.SND_MAX] |
| jg .not_uni_xfer |
| |
| ; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number. |
| sub eax, [ebx + TCP_SOCKET.SND_UNA] |
| jle .not_uni_xfer |
| |
| DEBUGF 1,"Header prediction: we are sender\n" |
| |
| ;--------------------------------- |
| ; Packet is a pure ACK, process it |
| |
| ; Update RTT estimators |
| |
| ; Delete acknowledged bytes from send buffer |
| |
| pusha |
| mov ecx, eax |
| lea eax, [ebx + STREAM_SOCKET.snd] |
| call SOCKET_ring_free |
| popa |
| |
| ; update window pointers |
| mov eax, [edx + TCP_segment.AckNumber] |
| dec eax |
| mov [ebx + TCP_SOCKET.SND_WL1], eax |
| |
| ; Stop retransmit timer |
| mov [ebx + TCP_SOCKET.timer_ack], 0 |
| |
| ; Awaken waiting processes |
| mov eax, ebx |
| call SOCKET_notify_owner |
| |
| ;; Generate more output FIXME |
| ;; mov eax, ebx |
| ;; call TCP_output |
| ;; |
| ;; jmp .drop |
| jmp .ack_processed |
| |
| ;------------------------------------------------- |
| ; maybe we are the receiver in the uni-xfer then.. |
| |
| .not_sender: |
| ; - The amount of data in the segment is greater than 0 (data count is in ecx) |
| |
| ; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment. |
| mov eax, [edx + TCP_segment.AckNumber] |
| cmp eax, [ebx + TCP_SOCKET.SND_UNA] |
| jne .not_uni_xfer |
| |
| ; - The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp). |
| |
| ;;; TODO |
| |
| jnz .not_uni_xfer |
| |
| ; Complete processing of received data |
| |
| DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx |
| |
| pusha |
| add esi, edx |
| lea eax, [ebx + STREAM_SOCKET.rcv] |
| call SOCKET_ring_write ; Add the data to the socket buffer |
| |
| mov eax, ebx |
| call SOCKET_notify_owner |
| popa |
| |
| add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied |
| or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag |
| |
| jmp .drop |
| |
| |
| |
| |
| |
| |
| ;-------------------------------------------------- |
| ; Header prediction failed, do it the slow way |
| |
| .not_uni_xfer: |
| |
| DEBUGF 1,"Header prediction failed\n" |
| |
| ; Calculate receive window size |
| |
| ;;;; |
| |
| cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN |
| je .LISTEN |
| |
| cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_SENT |
| je .SYN_SENT |
| |
| jmp .NOT_LISTEN_OR_SYN_SENT |
| |
| |
| |
| ;------------- |
| ; Passive Open |
| |
| align 4 |
| .LISTEN: |
| |
| DEBUGF 1,"TCP state: listen\n" |
| |
| test [edx + TCP_segment.Flags], TH_RST ;;; TODO: kill new socket on error |
| jnz .drop |
| |
| test [edx + TCP_segment.Flags], TH_ACK |
| jnz .drop_with_reset |
| |
| test [edx + TCP_segment.Flags], TH_SYN |
| jz .drop |
| |
| ;;; TODO: check if it's a broadcast or multicast, and drop if so |
| |
| add [TCP_sequence_num], 64000 |
| |
| push [edx + TCP_segment.SourcePort] |
| pop [eax + TCP_SOCKET.RemotePort] |
| |
| push [edx + TCP_segment.SequenceNumber] |
| pop [eax + TCP_SOCKET.IRS] |
| |
| push [eax + TCP_SOCKET.ISS] |
| pop [eax + TCP_SOCKET.SND_NXT] |
| |
| TCP_sendseqinit eax |
| TCP_rcvseqinit eax |
| |
| mov [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED |
| mov [eax + TCP_SOCKET.t_flags], TF_ACKNOW |
| mov [eax + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval ;;;; macro |
| |
| add eax, STREAM_SOCKET.snd |
| call SOCKET_ring_create |
| |
| add eax, STREAM_SOCKET.rcv - STREAM_SOCKET.snd |
| call SOCKET_ring_create |
| |
| lea ebx, [eax - STREAM_SOCKET.rcv] |
| mov [ebx + SOCKET.lock], 0 |
| |
| jmp .trim_then_step6 |
| |
| |
| |
| |
| |
| |
| |
| |
| ;------------ |
| ; Active Open |
| |
| align 4 |
| .SYN_SENT: |
| |
| DEBUGF 1,"TCP state: syn_sent\n" |
| |
| test [edx + TCP_segment.Flags], TH_ACK |
| jz @f |
| |
| mov eax, [edx + TCP_segment.AckNumber] |
| cmp eax, [ebx + TCP_SOCKET.ISS] |
| jle .drop_with_reset |
| |
| cmp eax, [ebx + TCP_SOCKET.SND_MAX] |
| jg .drop_with_reset |
| @@: |
| |
| test [edx + TCP_segment.Flags], TH_RST |
| jz @f |
| |
| test [edx + TCP_segment.Flags], TH_ACK |
| jz .drop |
| |
| mov eax, ebx |
| mov ebx, ECONNREFUSED |
| call TCP_drop |
| |
| jmp .drop |
| @@: |
| |
| test [edx + TCP_segment.Flags], TH_SYN |
| jz .drop |
| |
| ; at this point, segment seems to be valid |
| |
| test [edx + TCP_segment.Flags], TH_ACK |
| jz .no_syn_ack |
| |
| ; now, process received SYN in response to an active open |
| |
| mov eax, [edx + TCP_segment.AckNumber] |
| mov [ebx + TCP_SOCKET.SND_UNA], eax |
| cmp eax, [ebx + TCP_SOCKET.SND_NXT] |
| jle @f |
| mov [ebx + TCP_SOCKET.SND_NXT], eax |
| @@: |
| |
| .no_syn_ack: |
| |
| mov [ebx + TCP_SOCKET.timer_retransmission], 0 ; disable retransmission |
| |
| push [edx + TCP_segment.SequenceNumber] |
| pop [ebx + TCP_SOCKET.IRS] |
| |
| TCP_rcvseqinit ebx |
| |
| mov [ebx + TCP_SOCKET.t_flags], TF_ACKNOW |
| |
| mov eax, [ebx + TCP_SOCKET.SND_UNA] |
| cmp eax, [ebx + TCP_SOCKET.ISS] |
| jle .simultaneous_open |
| |
| test [edx + TCP_segment.Flags], TH_ACK |
| jz .simultaneous_open |
| |
| DEBUGF 1,"TCP: active open\n" |
| |
| ;;; TODO: update stats |
| |
| ; set socket state to connected |
| |
| mov [ebx + SOCKET.state],1 ;;;; FIXME |
| |
| mov [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED |
| |
| ;;; TODO: check if we should scale the connection (567-572) |
| ;;; TODO: update RTT estimators |
| |
| jmp .trim_then_step6 |
| |
| .simultaneous_open: |
| |
| DEBUGF 1,"TCP: simultaneous open\n" |
| ; We have received a syn but no ACK, so we are having a simultaneous open.. |
| mov [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED |
| |
| |
| |
| |
| |
| |
| |
| ;------------------------------------- |
| ; Common processing for receipt of SYN |
| |
| .trim_then_step6: |
| |
| inc [edx + TCP_segment.SequenceNumber] |
| |
| ;;; TODO: Drop any received data that follows receive window (590) |
| |
| mov eax, [edx + TCP_segment.SequenceNumber] |
| mov [ebx + TCP_SOCKET.RCV_UP], eax |
| dec eax |
| mov [ebx + TCP_SOCKET.SND_WL1], eax |
| |
| jmp .ack_processed |
| |
| |
| |
| |
| |
| |
| |
| |
| .NOT_LISTEN_OR_SYN_SENT: |
| |
| DEBUGF 1,"Slow TCP input: not listen or syn_sent state\n" |
| |
| ;-------------------------------------------- |
| ; Protection Against Wrapped Sequence Numbers |
| |
| ; First, check if timestamp is present |
| |
| ;;;; TODO |
| |
| ; Then, check if at least some bytes of data are within window |
| |
| ;;;; TODO |
| |
| |
| |
| |
| |
| |
| |
| |
| ;---------------------------- |
| ; trim any data not in window |
| |
| ; check for duplicate data at beginning of segment |
| |
| mov eax, [ebx + TCP_SOCKET.RCV_NXT] |
| sub eax, [edx + TCP_segment.SequenceNumber] |
| jz .no_duplicate |
| |
| test [edx + TCP_segment.Flags], TH_SYN |
| jz .no_drop |
| |
| ; remove duplicate syn |
| |
| and [edx + TCP_segment.Flags], not (TH_SYN) |
| inc [edx + TCP_segment.SequenceNumber] |
| |
| cmp [edx + TCP_segment.UrgentPointer], 1 |
| jl @f |
| |
| dec [edx + TCP_segment.UrgentPointer] |
| |
| jmp .no_drop |
| @@: |
| |
| and [edx + TCP_segment.Flags], not (TH_URG) |
| dec eax |
| jz .no_duplicate |
| .no_drop: |
| |
| DEBUGF 1,"Going to drop %u out of %u bytes\n", eax, ecx |
| |
| ; eax holds number of bytes to drop |
| |
| ; Check for entire duplicate packet |
| |
| cmp eax, ecx |
| jge .duplicate |
| |
| ;;; TODO: apply figure 28.30 |
| |
| ; Check for duplicate FIN |
| |
| test [edx + TCP_segment.Flags], TH_FIN |
| jz @f |
| inc ecx |
| cmp eax, ecx |
| dec ecx |
| jne @f |
| |
| mov eax, ecx |
| and [edx + TCP_segment.Flags], not TH_FIN |
| or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW |
| jmp .no_duplicate |
| @@: |
| |
| ; Handle the case when a bound socket connects to itself |
| ; Allow packets with a SYN and an ACKto continue with the processing |
| |
| ;------------------------------------- |
| ; Generate duplicate ACK if nescessary |
| |
| ; This code also handles simultaneous half-open or self-connects |
| |
| test eax, eax |
| jnz .drop_after_ack |
| |
| cmp [edx + TCP_segment.Flags], TH_ACK |
| jz .drop_after_ack |
| |
| .duplicate: |
| |
| DEBUGF 1,"Duplicate received\n" |
| |
| ;---------------------------------------- |
| ; Update statistics for duplicate packets |
| |
| ;;; TODO |
| |
| jmp .drop ;;; DROP the packet ?? |
| |
| .no_duplicate: |
| |
| ;----------------------------------------------- |
| ; Remove duplicate data and update urgent offset |
| |
| add [edx + TCP_segment.SequenceNumber], eax |
| |
| ;;; TODO |
| |
| sub [edx + TCP_segment.UrgentPointer], ax |
| jg @f |
| |
| and [edx + TCP_segment.Flags], not (TH_URG) |
| mov [edx + TCP_segment.UrgentPointer], 0 |
| @@: |
| |
| ;-------------------------------------------------- |
| ; Handle data that arrives after process terminates |
| |
| cmp [ebx + SOCKET.PID], 0 |
| jg @f |
| |
| cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSE_WAIT |
| jle @f |
| |
| test ecx, ecx |
| jz @f |
| |
| ;;; Close the socket |
| ;;; update stats |
| |
| jmp .drop_with_reset |
| @@: |
| |
| ;---------------------------------------- |
| ; Remove data beyond right edge of window |
| |
| mov eax, [edx + TCP_segment.SequenceNumber] |
| add eax, ecx |
| sub eax, [ebx + TCP_SOCKET.RCV_NXT] |
| sub ax, [ebx + TCP_SOCKET.RCV_WND] |
| |
| ; eax now holds the number of bytes to drop |
| |
| jle .no_excess_data |
| |
| ;;; TODO: update stats |
| |
| cmp eax, ecx |
| jl .dont_drop_all |
| |
| ;;; TODO 700-736 |
| |
| .dont_drop_all: |
| |
| .no_excess_data: |
| |
| |
| |
| |
| |
| |
| |
| |
| ;----------------- |
| ; Record timestamp |
| |
| ;;; TODO 737-746 |
| |
| |
| |
| |
| |
| ;------------------ |
| ; Process RST flags |
| |
| test [edx + TCP_segment.Flags], TH_RST |
| jz .rst_skip |
| |
| DEBUGF 1,"Got an RST flag" |
| |
| mov eax, [ebx + TCP_SOCKET.t_state] |
| shl eax, 2 |
| jmp dword [eax + .rst_sw_list] |
| |
| .rst_sw_list: |
| dd .rst_skip ;TCB_CLOSED |
| dd .rst_skip ;TCB_LISTEN |
| dd .rst_skip ;TCB_SYN_SENT |
| dd .econnrefused ;TCB_SYN_RECEIVED |
| dd .econnreset ;TCB_ESTABLISHED |
| dd .econnreset ;TCB_CLOSE_WAIT |
| dd .econnreset ;TCB_FIN_WAIT_1 |
| dd .rst_close ;TCB_CLOSING |
| dd .rst_close ;TCB_LAST_ACK |
| dd .econnreset ;TCB_FIN_WAIT_2 |
| dd .rst_close ;TCB_TIMED_WAIT |
| |
| .econnrefused: |
| |
| DEBUGF 1,"Connection refused" |
| |
| ;;; TODO: debug info |
| |
| jmp .close |
| |
| .econnreset: |
| |
| DEBUGF 1,"Connection reset" |
| |
| ;;; TODO: debug info |
| |
| .close: |
| |
| DEBUGF 1,"Closing connection" |
| |
| ;;; update stats |
| |
| .rst_close: |
| |
| DEBUGF 1,"Closing with reset\n" |
| |
| ;;; Close the socket |
| |
| jmp .drop |
| |
| .rst_skip: |
| |
| |
| |
| |
| |
| |
| |
| ;-------------------------------------- |
| ; handle SYN-full and ACK-less segments |
| |
| test [edx + TCP_segment.Flags], TH_SYN |
| jz @f |
| |
| mov ebx, ECONNRESET |
| call TCP_drop |
| |
| jmp .drop_with_reset |
| |
| test [edx + TCP_segment.Flags], TH_ACK |
| jz .drop |
| @@: |
| |
| |
| |
| |
| |
| |
| |
| |
| ;--------------- |
| ; ACK processing |
| |
| cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED |
| jnz .no_syn_rcv |
| |
| DEBUGF 1,"TCP state = syn received\n" |
| |
| ;;;;; 801-815 |
| |
| .no_syn_rcv: |
| |
| ; check for duplicate ACK |
| |
| mov eax, [edx + TCP_segment.AckNumber] |
| cmp eax, [ebx + TCP_SOCKET.SND_UNA] |
| jg .not_dup_ack |
| |
| DEBUGF 1,"Duplicate ACK\n" |
| |
| test ecx, ecx |
| jnz .ack_processed |
| |
| mov eax, dword [edx + TCP_segment.Window] |
| cmp eax, [ebx + TCP_SOCKET.SND_WND] |
| jne .ack_processed |
| |
| ; Process the duplicate ACK |
| |
| ;;;;; 833 - 878 |
| |
| ;;; call TCP_output |
| jmp .drop |
| |
| .not_dup_ack: |
| |
| DEBUGF 1,"new ACK\n" |
| |
| |
| |
| |
| |
| |
| |
| ;------------------------------------------------- |
| ; If the congestion window was inflated to account |
| ; for the other side's cached packets, retract it |
| |
| ;;;; 888 - 902 |
| |
| |
| |
| |
| |
| |
| |
| |
| ;------------------------------------------ |
| ; RTT measurements and retransmission timer |
| |
| ;;;;; 903 - 926 |
| |
| mov [ebx + TCP_SOCKET.timer_retransmission], 0 |
| |
| mov eax, [ebx + TCP_SOCKET.SND_MAX] |
| cmp eax, [edx + TCP_segment.AckNumber] |
| je .all_outstanding |
| mov [ebx + TCP_SOCKET.timer_retransmission], 120 ;;;; TODO: correct this value (use a macro for it) |
| .all_outstanding: |
| |
| |
| |
| |
| |
| |
| |
| ;------------------------------------------- |
| ; Open congestion window in response to ACKs |
| |
| ;;;; |
| |
| |
| |
| |
| |
| |
| |
| |
| ;------------------------------------------ |
| ; Remove acknowledged data from send buffer |
| |
| pusha |
| mov ecx, [edx + TCP_segment.AckNumber] |
| sub ecx, [ebx + TCP_SOCKET.SND_UNA] ; ecx now holds number of bytes acked |
| |
| lea eax, [ebx + STREAM_SOCKET.snd] |
| call SOCKET_ring_free |
| popa |
| |
| ; Wake up process waiting on send buffer |
| |
| mov eax, ebx |
| call SOCKET_notify_owner |
| |
| ; Update TCB |
| |
| mov eax, [edx + TCP_segment.AckNumber] |
| mov [ebx + TCP_SOCKET.SND_UNA], eax |
| |
| cmp eax, [ebx + TCP_SOCKET.SND_NXT] |
| jl @f |
| mov [ebx + TCP_SOCKET.SND_NXT], eax |
| @@: |
| |
| |
| |
| |
| |
| |
| ; General ACK handling complete |
| ; Now do the state-specific ones |
| |
| mov eax, [ebx + TCP_SOCKET.t_state] |
| jmp dword [eax*4 + .ACK_sw_list] |
| |
| .ACK_sw_list: |
| dd .ack_processed ;TCB_CLOSED |
| dd .ack_processed ;TCB_LISTEN |
| dd .ack_processed ;TCB_SYN_SENT |
| dd .ack_processed ;TCB_SYN_RECEIVED |
| dd .ack_processed ;TCB_ESTABLISHED |
| dd .ack_processed ;TCB_CLOSE_WAIT |
| dd .ack_fw1 ;TCB_FIN_WAIT_1 |
| dd .ack_c ;TCB_CLOSING |
| dd .ack_la ;TCB_LAST_ACK |
| dd .ack_processed ;TCB_FIN_WAIT_2 |
| dd .ack_tw ;TCB_TIMED_WAIT |
| |
| |
| .ack_fw1: ; 963 |
| |
| |
| jmp .ack_processed |
| |
| .ack_c: ; 958 |
| |
| jmp .ack_processed |
| |
| .ack_la: ; 999 |
| |
| jmp .ack_processed |
| |
| .ack_tw: ; 1010 |
| |
| jmp .ack_processed |
| |
| |
| |
| |
| align 4 |
| |
| .ack_processed: ; (step 6) |
| |
| DEBUGF 1,"ACK processed\n" |
| |
| ;---------------------------------------------- |
| ; check if we need to update window information |
| |
| test [edx + TCP_segment.Flags], TH_ACK |
| jz .no_window_update |
| |
| mov eax, [ebx + TCP_SOCKET.SND_WL1] |
| cmp eax, [edx + TCP_segment.SequenceNumber] |
| jl .update_window |
| jg @f |
| |
| mov eax, [ebx + TCP_SOCKET.SND_WL2] |
| cmp eax, [edx + TCP_segment.AckNumber] |
| jl .update_window |
| jg .no_window_update |
| @@: |
| |
| mov eax, [ebx + TCP_SOCKET.SND_WL2] |
| cmp eax, [edx + TCP_segment.AckNumber] |
| jne .no_window_update |
| |
| movzx eax, [edx + TCP_segment.Window] |
| cmp eax, [ebx + TCP_SOCKET.SND_WND] |
| jle .no_window_update |
| |
| .update_window: |
| |
| DEBUGF 1,"Updating window\n" |
| |
| ; Keep track of pure window updates |
| |
| ; test ecx, ecx |
| ; jz @f |
| ; |
| ; mov eax, [ebx + TCP_SOCKET.SND_WL2] |
| ; cmp eax, [edx + TCP_segment.AckNumber] |
| ; jne @f |
| ; |
| ; ;; mov eax, tiwin |
| ; cmp eax, [ebx + TCP_SOCKET.SND_WND] |
| ; jle @f |
| ; |
| ; ;;; update stats |
| ; |
| ; @@: |
| |
| mov eax, dword [edx + TCP_segment.Window] |
| cmp eax, [ebx + TCP_SOCKET.max_sndwnd] |
| jle @f |
| mov [ebx + TCP_SOCKET.max_sndwnd], eax |
| @@: |
| mov [ebx + TCP_SOCKET.SND_WND], eax |
| |
| push [edx + TCP_segment.SequenceNumber] |
| pop [ebx + TCP_SOCKET.SND_WL1] |
| |
| push [edx + TCP_segment.AckNumber] |
| pop [ebx + TCP_SOCKET.SND_WL2] |
| |
| ;;; needoutput = 1 |
| |
| .no_window_update: |
| |
| |
| |
| |
| |
| |
| |
| ;----------------- |
| ; process URG flag |
| |
| test [edx + TCP_segment.Flags], TH_URG |
| jz .not_urgent |
| |
| cmp [edx + TCP_segment.UrgentPointer], 0 |
| jz .not_urgent |
| |
| cmp [ebx + TCP_SOCKET.t_state], TCB_TIMED_WAIT |
| je .not_urgent |
| |
| ; Ignore bogus urgent offsets |
| |
| ;;; 1040-1050 |
| |
| movzx eax, [edx + TCP_segment.UrgentPointer] |
| add eax, [ebx + STREAM_SOCKET.rcv + RING_BUFFER.size] |
| cmp eax, SOCKET_MAXDATA |
| jle .not_urgent |
| |
| mov [edx + TCP_segment.UrgentPointer], 0 |
| and [edx + TCP_segment.Flags], not (TH_URG) |
| jmp .do_data |
| |
| .not_urgent: |
| |
| ; processing of received urgent pointer |
| |
| ;;; TODO (1051-1093) |
| |
| |
| |
| |
| |
| |
| |
| |
| ;-------------------------------- |
| ; process the data in the segment |
| |
| .do_data: |
| |
| DEBUGF 1,"TCP: do data (%u)\n", ecx |
| |
| test [edx + TCP_segment.Flags], TH_FIN |
| jnz .process_fin |
| |
| cmp [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1 |
| jge .dont_do_data |
| |
| test ecx, ecx |
| jz .final_processing |
| |
| DEBUGF 1,"Processing data in segment\n" |
| |
| ;; TODO: check if data is in sequence ! |
| |
| movzx eax, [edx + TCP_segment.DataOffset] ;;; todo: remember this in.. edi ? |
| and eax, 0xf0 |
| shr al, 2 |
| |
| lea esi, [edx + eax] |
| |
| or [ebx + TCP_SOCKET.t_flags], TF_DELACK |
| add [ebx + TCP_SOCKET.RCV_NXT], ecx |
| |
| lea eax, [ebx + STREAM_SOCKET.rcv] |
| call SOCKET_ring_write |
| |
| mov eax, ebx |
| call SOCKET_notify_owner |
| |
| jmp .final_processing |
| |
| |
| .dont_do_data: |
| |
| |
| |
| |
| |
| |
| |
| ;--------------- |
| ; FIN processing |
| |
| .process_fin: |
| |
| DEBUGF 1,"Processing FIN\n" |
| |
| mov eax, [ebx + TCP_SOCKET.t_state] |
| shl eax, 2 |
| jmp dword [eax + .FIN_sw_list] |
| |
| .FIN_sw_list: |
| dd .no_fin ;TCB_CLOSED |
| dd .no_fin ;TCB_LISTEN |
| dd .no_fin ;TCB_SYN_SENT |
| dd .fin_syn_est ;TCB_SYN_RECEIVED |
| dd .fin_syn_est ;TCB_ESTABLISHED |
| dd .no_fin ;TCB_CLOSE_WAIT |
| dd .fin_wait1 ;TCB_FIN_WAIT_1 |
| dd .no_fin ;TCB_CLOSING |
| dd .no_fin ;TCB_LAST_ACK |
| dd .fin_wait2 ;TCB_FIN_WAIT_2 |
| dd .fin_timed ;TCB_TIMED_WAIT |
| |
| |
| |
| .fin_syn_est: |
| |
| jmp .final_processing |
| |
| .fin_wait1: |
| |
| jmp .final_processing |
| |
| .fin_wait2: |
| |
| jmp .final_processing |
| |
| .fin_timed: |
| |
| jmp .final_processing |
| |
| .no_fin: |
| |
| |
| |
| |
| |
| |
| |
| |
| ;----------------- |
| ; Final processing |
| |
| .final_processing: |
| |
| DEBUGF 1,"Final processing\n" |
| |
| ;;; if debug enabled, output packet |
| |
| ;test needoutput, needoutput |
| ;jz .dumpit |
| |
| test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW |
| jz .dumpit |
| |
| DEBUGF 1,"ACK now!\n" |
| |
| push ebx |
| mov eax, ebx |
| call TCP_output |
| pop ebx |
| |
| .dumpit: |
| |
| mov [ebx + SOCKET.lock], 0 |
| |
| call kernel_free |
| add esp, 4 |
| ret |
| |
| |
| |
| |
| |
| |
| |
| ;------------------------------------------ |
| ; Generate an ACK, droping incoming segment |
| |
| align 4 |
| .drop_after_ack: |
| |
| DEBUGF 1,"Drop after ACK\n" |
| |
| test [edx + TCP_segment.Flags], TH_RST |
| jnz .drop |
| |
| and [ebx + TCP_SOCKET.t_flags], TF_ACKNOW |
| |
| mov [ebx + SOCKET.lock], 0 |
| |
| push ebx |
| mov eax, ebx |
| call TCP_output |
| pop ebx |
| |
| call kernel_free |
| add esp, 4 |
| ret |
| |
| |
| |
| |
| |
| |
| |
| |
| ;------------------------------------------- |
| ; Generate an RST, dropping incoming segment |
| |
| align 4 |
| .drop_with_reset: |
| |
| mov [ebx + SOCKET.lock], 0 |
| |
| .drop_with_reset_not_locked: |
| |
| DEBUGF 1,"Drop with reset\n" |
| |
| test [edx + TCP_segment.Flags], TH_RST |
| jnz .drop |
| |
| ;;; if its a multicast/broadcast, also drop |
| |
| test [edx + TCP_segment.Flags], TH_ACK |
| jnz .respond_ack |
| |
| test [edx + TCP_segment.Flags], TH_SYN |
| jnz .respond_syn |
| |
| call kernel_free |
| add esp, 4 |
| ret |
| |
| .respond_ack: |
| |
| mov dl, TH_RST |
| |
| push ebx |
| call TCP_respond_segment |
| pop ebx |
| |
| jmp .destroy_new_socket |
| |
| |
| .respond_syn: |
| |
| mov dl, TH_RST + TH_ACK |
| |
| push ebx |
| call TCP_respond_socket |
| pop ebx |
| |
| jmp .destroy_new_socket |
| |
| |
| |
| |
| |
| |
| |
| ;----- |
| ; Drop |
| |
| align 4 |
| .drop: |
| |
| mov [ebx + SOCKET.lock], 0 |
| |
| .drop_not_locked: |
| |
| DEBUGF 1,"Dropping packet\n" |
| |
| ;;;; If debugging options are enabled, output the packet somwhere |
| |
| .destroy_new_socket: |
| |
| ;;;; kill the newly created socket |
| |
| call kernel_free |
| add esp, 4 |
| ret |
| Property changes: |
|---|
| Added: svn:keywords |
|---|
| +Revision |
|---|
| \ No newline at end of property |
|---|