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Client:
C -> P: PORT 1,2,3,4,5,6 P -> S: PORT 9,8,7,6,5,4
C <- P: 200 OK P <- S: 200 OK
C -> P: PASV P -> S: PASV
C <- P: 227 (1,2,3,4,5,6) P <- S: 227 (9,8,7,6,5,4)
Order of operations:
C -> P: PORT
Parse addr/port
Check RFC1918 addr
Check AllowForeignAddress
Check high-numbered port
Open local listening conn
Format local listening addr for PORT command
Send new PORT command to S
Receive 200 OK response from S
Send 200 OK response to C
Set frontend_sess_flags = SF_PORT
Set backend_sess_flags = SF_PORT
C -> P: PASV
Send PASV command to S
Receive 227 response from S
Parse addr/port
Check addr against remote addr
Check high-numbered port
Open local listening conn
Format local listening addr for PASV response
Send new PASV response to C
Set frontend_sess_flags = SF_PASSIVE
Set backend_sess_flags = SF_PASSIVE
Active:
C -> P: PORT 1,2,3,4,5,6 P -> S: PORT 9,8,7,6,5,4
C <- P: 200 OK P <- S: 200 OK
C -> P: PASV P -> S: PORT 9,8,7,6,5,4
C <- P: 227 (1,2,3,4,5,6) P <- S: 200 OK
Order of operations:
C -> P: PORT
Parse addr/port
Check RFC1918 addr
Check AllowForeignAddress
Check high-numbered port
Open local listening conn
Format local listening addr for PORT command
Send new PORT command to S
Receive 200 OK response from S
Send 200 OK response to C
Set frontend_sess_flags = SF_PORT
Set backend_sess_flags = SF_PORT
C -> P: PASV
Open local listening conn
Format local listening addr for PORT command
Send new PORT command to S
Receive 200 OK response from S
Open local listening conn
Format local listening addr for PASV response
Send new PASV response to C
Set frontend_sess_flags = SF_PASSIVE
Set backend_sess_flags = SF_PORT
Passive:
C -> P: PORT 1,2,3,4,5,6 P -> S: PASV
C <- P: 200 OK P <- S: 227 (9,8,7,6,5,4)
C -> P: PASV P -> S: PASV
C <- P: 227 (1,2,3,4,5,6) P <- S: 227 (9,8,7,6,5,4)
Order of operations:
C -> P: PORT
Parse addr/port
Check RFC1918 addr
Check AllowForeignAddress
Check high-numbered port
Send new PASV command to S
Receive 227 responses from S
Parse addr/port
Check addr against remote addr
Check high-numbered port
Send 200 OK response to C
Set frontend_sess_flags = SF_PORT
Set backend_sess_flags = SF_PASSIVE
C -> P: PASV
Send PASV command to S
Receive 227 response from S
Parse addr/port
Check addr against remote addr
Check high-numbered port
Open local listening conn
Format local listening addr for PASV response
Send new PASV response to C
Set frontend_sess_flags = SF_PASSIVE
Set backend_sess_flags = SF_PASSIVE
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