diff options
Diffstat (limited to 'ps.c')
| -rw-r--r-- | ps.c | 66 |
1 files changed, 63 insertions, 3 deletions
@@ -81,7 +81,7 @@ headc (const struct buffer *buf) } #endif -static void +static inline void close_socket_if_defined (const socket_descriptor_t sd) { if (socket_defined (sd)) @@ -154,6 +154,13 @@ send_control (const socket_descriptor_t fd, int code) return -1; } +/* + * Send a command (char), data (head), and a file descriptor (sd_send) to a local process + * over unix socket sd. Unfortunately, there's no portable way to send file descriptors + * to other processes, so this code, as well as its analog (control_message_from_parent below), + * is Linux-specific. This function runs in the context of the main process and is used to + * send commands, data, and file descriptors to the background process. + */ static void port_share_sendmsg (const socket_descriptor_t sd, const char command, @@ -231,7 +238,9 @@ pc_list_len (struct proxy_connection *pc) return count; } -/* mark a proxy entry and its counterpart for close */ +/* + * Mark a proxy entry and its counterpart for close. + */ static void proxy_entry_mark_for_close (struct proxy_connection *pc, struct event_set *es) { @@ -256,6 +265,10 @@ proxy_entry_mark_for_close (struct proxy_connection *pc, struct event_set *es) } } +/* + * Run through the proxy entry list and delete all entries marked + * for close. + */ static void proxy_list_housekeeping (struct proxy_connection **list) { @@ -282,6 +295,9 @@ proxy_list_housekeeping (struct proxy_connection **list) } } +/* + * Cleanup function, on proxy process exit. + */ static void proxy_list_close (struct proxy_connection **list) { @@ -318,6 +334,13 @@ proxy_connection_io_requeue (struct proxy_connection *pc, const int rwflags_new, } } +/* + * Create a new pair of proxy_connection entries, one for each + * socket file descriptor involved in the proxy. We are given + * the client fd, and we should derive our own server fd by connecting + * to the server given by server_addr/server_port. Return true + * on success and false on failure to connect to server. + */ static bool proxy_entry_new (struct proxy_connection **list, struct event_set *es, @@ -381,6 +404,12 @@ proxy_entry_new (struct proxy_connection **list, return true; } +/* + * This function runs in the context of the background proxy process. + * Receive a control message from the parent (sent by the port_share_sendmsg + * function above) and act on it. Return false if the proxy process should + * exit, true otherwise. + */ static bool control_message_from_parent (const socket_descriptor_t sd_control, struct proxy_connection **list, @@ -466,7 +495,14 @@ control_message_from_parent (const socket_descriptor_t sd_control, #define IOSTAT_EAGAIN_ON_WRITE 1 #define IOSTAT_ERROR 2 -/* forward data from pc to pc->counterpart */ +/* + * Forward data from pc to pc->counterpart. + * Return values: + * + * IOSTAT_EAGAIN_ON_READ -- recv returned EAGAIN + * IOSTAT_EAGAIN_ON_WRITE -- send return EAGAIN + * IOSTAT_ERROR -- the other end of one of our sockets was closed + */ static int proxy_connection_io_xfer (struct proxy_connection *pc) { @@ -516,6 +552,9 @@ proxy_connection_io_xfer (struct proxy_connection *pc) return IOSTAT_ERROR; } +/* + * Decide how the receipt of an EAGAIN status should affect our next IO queueing. + */ static inline bool proxy_connection_io_status (const int status, int *rwflags_pc, int *rwflags_cp) { @@ -534,6 +573,10 @@ proxy_connection_io_status (const int status, int *rwflags_pc, int *rwflags_cp) } } +/* + * Dispatch function for forwarding data between the two socket fds involved + * in the proxied connection. + */ static bool proxy_connection_io_dispatch (struct proxy_connection *pc, const int rwflags, @@ -566,6 +609,9 @@ proxy_connection_io_dispatch (struct proxy_connection *pc, return false; } +/* + * This is the main function for the port share proxy background process. + */ static void port_share_proxy (const in_addr_t hostaddr, const int port, const socket_descriptor_t sd_control) { @@ -629,6 +675,10 @@ port_share_proxy (const in_addr_t hostaddr, const int port, const socket_descrip msg (D_PS_PROXY, "PORT SHARE PROXY: proxy exiting"); } +/* + * Called from the main OpenVPN process to enable the port + * share proxy. + */ struct port_share * port_share_open (const char *host, const int port) { @@ -754,6 +804,11 @@ port_share_abort (struct port_share *ps) } } +/* + * Given either the first 2 or 3 bytes of an initial client -> server + * data payload, return true if the protocol is that of an OpenVPN + * client attempting to connect with an OpenVPN server. + */ bool is_openvpn_protocol (const struct buffer *buf) { @@ -773,6 +828,11 @@ is_openvpn_protocol (const struct buffer *buf) return true; } +/* + * Called from the foreground process. Send a message to the background process that it + * should proxy the TCP client on sd to the host/port defined in the initial port_share_open + * call. + */ void port_share_redirect (struct port_share *ps, const struct buffer *head, socket_descriptor_t sd) { |