| 1 | /* |
| 2 | * Network proxy abstraction in PuTTY |
| 3 | * |
| 4 | * A proxy layer, if necessary, wedges itself between the |
| 5 | * network code and the higher level backend. |
| 6 | * |
| 7 | * Supported proxies: HTTP CONNECT, generic telnet, SOCKS 4 & 5 |
| 8 | */ |
| 9 | |
| 10 | #ifndef PUTTY_PROXY_H |
| 11 | #define PUTTY_PROXY_H |
| 12 | |
| 13 | #define PROXY_ERROR_GENERAL 8000 |
| 14 | #define PROXY_ERROR_UNEXPECTED 8001 |
| 15 | |
| 16 | typedef struct Socket_proxy_tag * Proxy_Socket; |
| 17 | |
| 18 | struct Socket_proxy_tag { |
| 19 | const struct socket_function_table *fn; |
| 20 | /* the above variable absolutely *must* be the first in this structure */ |
| 21 | |
| 22 | char * error; |
| 23 | |
| 24 | Socket sub_socket; |
| 25 | Plug plug; |
| 26 | SockAddr remote_addr; |
| 27 | int remote_port; |
| 28 | |
| 29 | bufchain pending_output_data; |
| 30 | bufchain pending_oob_output_data; |
| 31 | int pending_flush; |
| 32 | bufchain pending_input_data; |
| 33 | |
| 34 | #define PROXY_STATE_NEW -1 |
| 35 | #define PROXY_STATE_ACTIVE 0 |
| 36 | |
| 37 | int state; /* proxy states greater than 0 are implementation |
| 38 | * dependent, but represent various stages/states |
| 39 | * of the initialization/setup/negotiation with the |
| 40 | * proxy server. |
| 41 | */ |
| 42 | int freeze; /* should we freeze the underlying socket when |
| 43 | * we are done with the proxy negotiation? this |
| 44 | * simply caches the value of sk_set_frozen calls. |
| 45 | */ |
| 46 | |
| 47 | #define PROXY_CHANGE_NEW -1 |
| 48 | #define PROXY_CHANGE_CLOSING 0 |
| 49 | #define PROXY_CHANGE_SENT 1 |
| 50 | #define PROXY_CHANGE_RECEIVE 2 |
| 51 | #define PROXY_CHANGE_ACCEPTING 3 |
| 52 | |
| 53 | /* something has changed (a call from the sub socket |
| 54 | * layer into our Proxy Plug layer, or we were just |
| 55 | * created, etc), so the proxy layer needs to handle |
| 56 | * this change (the type of which is the second argument) |
| 57 | * and further the proxy negotiation process. |
| 58 | */ |
| 59 | |
| 60 | int (*negotiate) (Proxy_Socket /* this */, int /* change type */); |
| 61 | |
| 62 | /* current arguments of plug handlers |
| 63 | * (for use by proxy's negotiate function) |
| 64 | */ |
| 65 | |
| 66 | /* closing */ |
| 67 | const char *closing_error_msg; |
| 68 | int closing_error_code; |
| 69 | int closing_calling_back; |
| 70 | |
| 71 | /* receive */ |
| 72 | int receive_urgent; |
| 73 | char *receive_data; |
| 74 | int receive_len; |
| 75 | |
| 76 | /* sent */ |
| 77 | int sent_bufsize; |
| 78 | |
| 79 | /* accepting */ |
| 80 | OSSocket accepting_sock; |
| 81 | |
| 82 | /* configuration, used to look up proxy settings */ |
| 83 | Config cfg; |
| 84 | |
| 85 | /* CHAP transient data */ |
| 86 | int chap_num_attributes; |
| 87 | int chap_num_attributes_processed; |
| 88 | int chap_current_attribute; |
| 89 | int chap_current_datalen; |
| 90 | }; |
| 91 | |
| 92 | typedef struct Plug_proxy_tag * Proxy_Plug; |
| 93 | |
| 94 | struct Plug_proxy_tag { |
| 95 | const struct plug_function_table *fn; |
| 96 | /* the above variable absolutely *must* be the first in this structure */ |
| 97 | |
| 98 | Proxy_Socket proxy_socket; |
| 99 | |
| 100 | }; |
| 101 | |
| 102 | extern void proxy_activate (Proxy_Socket); |
| 103 | |
| 104 | extern int proxy_http_negotiate (Proxy_Socket, int); |
| 105 | extern int proxy_telnet_negotiate (Proxy_Socket, int); |
| 106 | extern int proxy_socks4_negotiate (Proxy_Socket, int); |
| 107 | extern int proxy_socks5_negotiate (Proxy_Socket, int); |
| 108 | |
| 109 | /* |
| 110 | * This may be reused by local-command proxies on individual |
| 111 | * platforms. |
| 112 | */ |
| 113 | char *format_telnet_command(SockAddr addr, int port, const Config *cfg); |
| 114 | |
| 115 | /* |
| 116 | * These are implemented in cproxy.c or nocproxy.c, depending on |
| 117 | * whether encrypted proxy authentication is available. |
| 118 | */ |
| 119 | extern void proxy_socks5_offerencryptedauth(char *command, int *len); |
| 120 | extern int proxy_socks5_handlechap (Proxy_Socket p); |
| 121 | extern int proxy_socks5_selectchap(Proxy_Socket p); |
| 122 | |
| 123 | #endif |