fix: SOCKS5 기능 복구

opt.h

@@ -19,7 +19,7 @@
  * Proxy server settings
  **********************************************************************************************************************/
 
-#define PROXY_SERVER_LISTENING_INTERFACE INTERFACE_LWIP // change this: INTERFACE_NATIVE or INTERFACE_LWIP
+#define PROXY_SERVER_LISTENING_INTERFACE INTERFACE_NATIVE // change this: INTERFACE_NATIVE or INTERFACE_LWIP
 
 // When you use INTERFACE_NATIVE, you use the following settings.
 #define PROXY_SERVER_NATIVE_LISTENING_ADDRESS "127.0.0.1"
@@ -51,7 +51,7 @@
  * Proxy client settings
  **********************************************************************************************************************/
 
-#define PROXY_CLIENT_REMOTE_INTERFACE INTERFACE_LWIP // change this: INTERFACE_NATIVE or INTERFACE_LWIP
+#define PROXY_CLIENT_REMOTE_INTERFACE INTERFACE_NATIVE // change this: INTERFACE_NATIVE or INTERFACE_LWIP
 
 // Listening side settings.
 #define PROXY_CLIENT_LISTENING_ADDRESS "127.0.0.1"

proxy_server.c

@@ -102,6 +102,7 @@ void app_loop(crossbar *client_crossbar, crossbar *remote_crossbar) {
  switch (version) {
  case SOCKS_VERSION5: {
  if (socks5_auth(conn_fd, methods) < 0) {
+ socks5_auth_not_supported(conn_fd);
  log_message("app_loop() Socks auth failed.");
  lwip_close(conn_fd);
  continue;
@@ -201,8 +202,8 @@ void app_loop(crossbar *client_crossbar, crossbar *remote_crossbar) {
  case SOCKS_VERSION4: {
  switch (methods) {
  case 1: {
- unsigned short int p;
- if (socks_read_port(conn_fd, &p) < 0) {
+ unsigned short int port;
+ if (socks_read_port(conn_fd, &port) < 0) {
  log_message("app_loop() Socks read port failed.");
  lwip_close(conn_fd);
  continue;
@@ -231,17 +232,17 @@ void app_loop(crossbar *client_crossbar, crossbar *remote_crossbar) {
  }
  log_message("Socks4A: ident:%s; domain:%s;", ident, domain);
 
- if ((remote_fd = request_connect(SOCKS_ADDR_DOMAINNAME, domain, p)) < 0) {
+ if ((remote_fd = request_connect(SOCKS_ADDR_DOMAINNAME, domain, port)) < 0) {
  socks4_send_response(conn_fd, 0x5a);
  lwip_close(conn_fd);
  log_message("app_loop() socks request failed.");
  free(ip);
  continue;
  }
  } else {
- log_message("Socks4: connect by ip & port", ip, p);
+ log_message("Socks4: connect by ip & port", ip, port);
 
- if ((remote_fd = request_connect(SOCKS_ADDR_IPV4, ip, p)) < 0) {
+ if ((remote_fd = request_connect(SOCKS_ADDR_IPV4, ip, port)) < 0) {
  socks4_send_response(conn_fd, 0x5b);
  lwip_close(conn_fd);
  log_message("app_loop() socks request failed.");

socks.c

@@ -17,7 +17,9 @@
 #include <quiet-lwip/lwip-socket.h>
 
 #if PROXY_SERVER_LISTENING_INTERFACE == INTERFACE_NATIVE
+
 #include "lwip_mock.h"
+
 #endif
 
 int socks_invitation(int socket_fd, int *version, int *methods) {
@@ -154,31 +156,36 @@ int request_connect(int type, void *buf, unsigned short int port) {
 }
 
 int readn(int fd, void *buf, int n) {
- int nread, left = n;
+ int nread;
+ int left = n;
+
  while (left > 0) {
- if ((nread = lwip_read(fd, buf, left)) == -1) {
+ nread = lwip_read(fd, buf, left);
+
+ if (nread == -1) {
  if (errno == EINTR || errno == EAGAIN) {
- errno = 0; // ignore
+ errno = 0; // just ignore the error.
  continue;
- }
- } else {
- if (nread == 0) {
- return 0;
  } else {
- left -= nread;
- buf += nread;
+ return -1;
  }
+ } else if (nread == 0) {
+ return 0;
  }
+
+ left -= nread;
+ buf += nread;
  }
+
  return n;
 }
 
-int readnull(int fd, char *buf, int size) {
- char sym = 0;
- int nread = 0;
+int readnull(int fd, char *buf, int max) {
+ int nread;
  int i = 0;
+ char sym = 0;
 
- while (i < size) {
+ while (i < max) {
  nread = lwip_recv(fd, &sym, sizeof(char), 0);
 
  if (nread <= 0) {
@@ -197,20 +204,26 @@ int readnull(int fd, char *buf, int size) {
 }
 
 int writen(int fd, void *buf, int n) {
- int nwrite, left = n;
+ int nwrite;
+ int left = n;
+
  while (left > 0) {
- if ((nwrite = lwip_write(fd, buf, left)) == -1) {
+ nwrite = lwip_write(fd, buf, left);
+
+ if (nwrite == -1) {
  if (errno == EINTR || errno == EAGAIN) {
+ errno = 0; // just ignore the error.
  continue;
- }
- } else {
- if (nwrite == n) {
- return 0;
  } else {
- left -= nwrite;
- buf += nwrite;
+ return -1;
  }
+ } else if (nwrite == n) {
+ return 0;
  }
+
+ left -= nwrite;
+ buf += nwrite;
  }
- return n;
+
+ return 0;
 }

socks.h

@@ -13,7 +13,8 @@ enum socks_version {
 };
 
 enum socks_auth {
- SOCKS_AUTH_NOAUTH = 0
+ SOCKS_AUTH_NOAUTH = 0,
+ SOCKS_AUTH_NOMETHOD = 255
 };
 
 enum socks_command {
@@ -38,10 +39,63 @@ int socks_read_port(int socket_fd, unsigned short int *port);
 
 int request_connect(int type, void *buf, unsigned short int port);
 
+/**
+ * Read n bytes from fd and put them into buf.
+ *
+ * This function consists of subsequent read() calls.
+ * Calls will be repeated until n bytes are read or an error occurs.
+ * Note: EINTER and EAGAIN are not considered as errors. They will be ignored.
+ *
+ * It will not return on partial reads. It waits until n bytes are read, and then this function returns.
+ *
+ * It is convenient to use this function when you want to grab n bytes without regards to partial reads.
+ *
+ * @param fd file descriptor of socket from where to read.
+ * @param buf a buffer where the bytes read will be stored.
+ * @param n read how many?
+ * @return n if success, 0 if connection closed, -1 if error.
+ */
 int readn(int fd, void *buf, int n);
 
-int readnull(int fd, char *buf, int size);
+/**
+ * Read maximum size bytes from fd until null character comes, and put them into buf.
+ *
+ * This function consists of subsequent read() calls.
+ * Calls will be repeated until one of the following conditions occurs:
+ * - null character comes
+ * - size bytes are read
+ * - an error occurs(including EINTER and EAGAIN).
+ *
+ * Any of the above conditions will immediately stop the read loop and make it return the number of bytes read so far.
+ * Note that the null character *is* included in the bytes count and the buffer.
+ *
+ * Beware that this functions lacks a error check functionality. :-)
+ *
+ * It is convenient to use this function, because it is good at reading a null terminated strings.
+ *
+ * @param fd file descriptor of socket from where to read.
+ * @param buf a buffer where the bytes read will be stored.
+ * @param max maximum size to read.
+ * @return number of bytes read so far.
+ */
+int readnull(int fd, char *buf, int max);
 
+/**
+ * Write n bytes from buf into fd.
+ *
+ * This function consists of subsequent write() calls.
+ * Calls will be repeated until n bytes are written or an error occurs.
+ * Note: EINTER and EAGAIN are not considered as errors. They will be ignored.
+ *
+ * It will not return on partial writes. It waits until n bytes are written, and then this function returns.
+ *
+ * It is convenient to use this function when you want to put n bytes without regards to partial writes.
+ *
+ * @param fd file descriptor of socket to where to write.
+ * @param buf the source buffer
+ * @param n write how many?
+ * @return 0 if success, -1 if error.
+ */
 int writen(int fd, void *buf, int n);
 
 #endif //QUIET_PRACTICE_SOCKS_H

socks4.c

@@ -31,7 +31,7 @@ int socks4_is_4a(const char *ip) {
 int socks4_send_response(int fd, int status) {
  char response[8] = {0x00, (char) status, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
 
- if (writen(fd, response, ARRAY_SIZE(response)) < (int)ARRAY_SIZE(response)) {
+ if (writen(fd, response, ARRAY_SIZE(response)) != 0) {
  return -1;
  }
 

socks5.c

@@ -9,6 +9,8 @@
 #include "relay.h"
 
 int socks5_auth(int socket_fd, int methods) {
+ int supported = -1;
+
  for (int i = 0; i < methods; i++) {
  char method;
  int n = readn(socket_fd, &method, 1);
@@ -19,19 +21,29 @@ int socks5_auth(int socket_fd, int methods) {
 
  if (method == SOCKS_AUTH_NOAUTH) {
  // support only SOCKS_AUTH_NOAUTH
- return 0;
+ supported = 0;
  }
  }
 
- return -1;
+ return supported;
 }
 
-int socks5_auth_reply(int socket_fd) {
- int answer[] = {SOCKS_VERSION5, SOCKS_AUTH_NOAUTH};
+int socks5_auth_not_supported(int socket_fd) {
+ char answer[2] = {SOCKS_VERSION5, SOCKS_AUTH_NOMETHOD};
+ if (writen(socket_fd, (void *) answer, ARRAY_SIZE(answer)) != 0) {
+ return -1;
+ }
+
+ return 0;
+}
 
- int written = writen(socket_fd, answer, ARRAY_SIZE(answer));
+int socks5_auth_reply(int socket_fd) {
+ char answer[] = {SOCKS_VERSION5, SOCKS_AUTH_NOAUTH};
+ if (writen(socket_fd, answer, ARRAY_SIZE(answer)) != 0) {
+ return -1;
+ }
 
- return (written == 2) ? 0 : -1;
+ return 0;
 }
 
 int socks5_command(int socket_fd, int *command) {
@@ -43,6 +55,8 @@ int socks5_command(int socket_fd, int *command) {
  return -1;
  }
 
+ log_message("Command %hhX %hhX %hhX %hhX", cmd[0], cmd[1],cmd[2], cmd[3]);
+
  if (cmd[0] != SOCKS_VERSION5) {
  log_message("socks5_command() invalid version: %d.", cmd[0]);
  return -1;
@@ -60,7 +74,7 @@ int socks5_command(int socket_fd, int *command) {
  return -1;
  }
 
- *command = (int) cmd[1];
+ *command = (int) cmd[3];
 
  return 0;
 }
@@ -92,19 +106,19 @@ int socks5_read_domain(int socket_fd, char **domain, int *domain_len) {
 int socks5_domain_send_response(int socket_fd, char *domain, int domain_len, unsigned short int port) {
  char response[] = {SOCKS_VERSION5, SOCKS_CONN_SUCCEEDED, 0, SOCKS_ADDR_DOMAINNAME};
 
- if (writen(socket_fd, response, ARRAY_SIZE(response)) < (int)ARRAY_SIZE(response)) {
+ if (writen(socket_fd, response, ARRAY_SIZE(response)) != 0) {
  return -1;
  }
 
- if (writen(socket_fd, &domain_len, sizeof(char)) < (int)sizeof(char)) {
+ if (writen(socket_fd, &domain_len, sizeof(char)) != 0) {
  return -1;
  }
 
- if (writen(socket_fd, domain, domain_len * sizeof(char)) < domain_len * (int)sizeof(char)) {
+ if (writen(socket_fd, domain, domain_len * sizeof(char)) != 0) {
  return -1;
  }
 
- if (writen(socket_fd, &port, sizeof(port)) < (int)sizeof(port)) {
+ if (writen(socket_fd, &port, sizeof(port)) != 0) {
  return -1;
  }
 
@@ -114,15 +128,15 @@ int socks5_domain_send_response(int socket_fd, char *domain, int domain_len, uns
 int socks5_ip_send_response(int socket_fd, char *ip, unsigned short int port) {
  char response[] = {SOCKS_VERSION5, SOCKS_CONN_SUCCEEDED, 0, SOCKS_ADDR_IPV4};
 
- if (writen(socket_fd, response, ARRAY_SIZE(response)) < (int)ARRAY_SIZE(response)) {
+ if (writen(socket_fd, response, ARRAY_SIZE(response)) != 0) {
  return -1;
  }
 
- if (writen(socket_fd, ip, IPSIZE * sizeof(char)) < IPSIZE * (int)sizeof(char)) {
+ if (writen(socket_fd, ip, IPSIZE * sizeof(char)) != 0) {
  return -1;
  }
 
- if (writen(socket_fd, &port, sizeof(port)) < 2) {
+ if (writen(socket_fd, &port, sizeof(port)) != 0) {
  return -1;
  }
 

socks5.h

@@ -7,6 +7,8 @@
 
 int socks5_auth(int socket_fd, int methods);
 
+int socks5_auth_not_supported(int socket_fd);
+
 int socks5_auth_reply(int socket_fd);
 
 int socks5_command(int socket_fd, int *command);