Dmitriy Sergeyev provided a patch that made the SOCKS[45] code work better as

it now will read the full data sent from servers. The SOCKS-related code was
also moved to the new lib/socks.c source file.

1 files changed, 549 insertions, 0 deletions

diff --git a/lib/socks.c b/lib/socks.c
new file mode 100644
index 000000000..acf6eb61c
--- /dev/null
+++ b/lib/socks.c
@@ -0,0 +1,549 @@
+#include "setup.h"
+
+#include "urldata.h"
+#include "sendf.h"
+#include "strequal.h"
+#include "select.h"
+#include "connect.h"
+#include "timeval.h"
+#include "socks.h"
+
+/* The last #include file should be: */
+#include "memdebug.h"
+
+/*
+ * Helper read-from-socket functions. Does the same as Curl_read() but it
+ * blocks until all bytes amount of buffersize will be read. No more, no less.
+ *
+ * This is STUPID BLOCKING behaviour which we frown upon, but right now this
+ * is what we have...
+ */
+static int blockread_all(struct connectdata *conn, /* connection data */
+                         curl_socket_t sockfd,     /* read from this socket */
+                         char *buf,                /* store read data here */
+                         ssize_t buffersize,       /* max amount to read */
+                         ssize_t *n,               /* amount bytes read */
+                         long conn_timeout)        /* timeout for data wait
+                                                      relative to
+                                                      conn->created */
+{
+  ssize_t nread;
+  ssize_t allread = 0;
+  int result;
+  struct timeval tvnow;
+  long conntime;
+  *n = 0;
+  do {
+    tvnow = Curl_tvnow();
+    /* calculating how long connection is establishing */
+    conntime = Curl_tvdiff(tvnow, conn->created);
+    if(conntime > conn_timeout) {
+      /* we already got the timeout */
+      return -1;
+    }
+    if(Curl_select(sockfd, CURL_SOCKET_BAD,
+                   (int)(conn_timeout - conntime)) <= 0) {
+      return -1;
+    }
+    result = Curl_read(conn, sockfd, buf, buffersize, &nread);
+    if(result)
+      return result;
+
+    if(buffersize == nread) {
+      allread += nread;
+      *n = allread;
+      return CURLE_OK;
+    }
+    buffersize -= nread;
+    buf += nread;
+    allread += nread;
+  } while(1);
+}
+
+/*
+* This function logs in to a SOCKS4 proxy and sends the specifics to the final
+* destination server.
+*
+* Reference :
+*   http://socks.permeo.com/protocol/socks4.protocol
+*
+* Note :
+*   Nonsupport "SOCKS 4A (Simple Extension to SOCKS 4 Protocol)"
+*   Nonsupport "Identification Protocol (RFC1413)"
+*/
+CURLcode Curl_SOCKS4(const char *proxy_name,
+                     struct connectdata *conn)
+{
+  unsigned char socksreq[262]; /* room for SOCKS4 request incl. user id */
+  int result;
+  CURLcode code;
+  curl_socket_t sock = conn->sock[FIRSTSOCKET];
+  long timeout;
+  struct SessionHandle *data = conn->data;
+
+  /* get timeout */
+  if(data->set.timeout && data->set.connecttimeout) {
+    if (data->set.timeout < data->set.connecttimeout)
+      timeout = data->set.timeout*1000;
+    else
+      timeout = data->set.connecttimeout*1000;
+  }
+  else if(data->set.timeout)
+    timeout = data->set.timeout*1000;
+  else if(data->set.connecttimeout)
+    timeout = data->set.connecttimeout*1000;
+  else
+    timeout = DEFAULT_CONNECT_TIMEOUT;
+
+  Curl_nonblock(sock, FALSE);
+
+  /*
+   * Compose socks4 request
+   *
+   * Request format
+   *
+   *     +----+----+----+----+----+----+----+----+----+----+....+----+
+   *     | VN | CD | DSTPORT |      DSTIP        | USERID       |NULL|
+   *     +----+----+----+----+----+----+----+----+----+----+....+----+
+   * # of bytes:  1    1      2              4           variable       1
+   */
+
+  socksreq[0] = 4; /* version (SOCKS4) */
+  socksreq[1] = 1; /* connect */
+  *((unsigned short*)&socksreq[2]) = htons(conn->remote_port);
+
+  /* DNS resolve */
+  {
+    struct Curl_dns_entry *dns;
+    Curl_addrinfo *hp=NULL;
+    int rc;
+
+    rc = Curl_resolv(conn, conn->host.name, (int)conn->remote_port, &dns);
+
+    if(rc == CURLRESOLV_ERROR)
+      return CURLE_COULDNT_RESOLVE_PROXY;
+
+    if(rc == CURLRESOLV_PENDING)
+      /* this requires that we're in "wait for resolve" state */
+      rc = Curl_wait_for_resolv(conn, &dns);
+
+    /*
+     * We cannot use 'hostent' as a struct that Curl_resolv() returns.  It
+     * returns a Curl_addrinfo pointer that may not always look the same.
+     */
+    if(dns)
+      hp=dns->addr;
+    if (hp) {
+      char buf[64];
+      unsigned short ip[4];
+      Curl_printable_address(hp, buf, sizeof(buf));
+
+      if(4 == sscanf( buf, "%hu.%hu.%hu.%hu",
+                      &ip[0], &ip[1], &ip[2], &ip[3])) {
+        /* Set DSTIP */
+        socksreq[4] = (unsigned char)ip[0];
+        socksreq[5] = (unsigned char)ip[1];
+        socksreq[6] = (unsigned char)ip[2];
+        socksreq[7] = (unsigned char)ip[3];
+      }
+      else
+        hp = NULL; /* fail! */
+
+      Curl_resolv_unlock(data, dns); /* not used anymore from now on */
+
+    }
+    if(!hp) {
+      failf(data, "Failed to resolve \"%s\" for SOCKS4 connect.",
+            conn->host.name);
+      return CURLE_COULDNT_RESOLVE_HOST;
+    }
+  }
+
+  /*
+   * This is currently not supporting "Identification Protocol (RFC1413)".
+   */
+  socksreq[8] = 0; /* ensure empty userid is NUL-terminated */
+  if (proxy_name)
+    strlcat((char*)socksreq + 8, proxy_name, sizeof(socksreq) - 8);
+
+  /*
+   * Make connection
+   */
+  {
+    ssize_t actualread;
+    ssize_t written;
+    int packetsize = 9 +
+      (int)strlen((char*)socksreq + 8); /* size including NUL */
+
+    /* Send request */
+    code = Curl_write(conn, sock, (char *)socksreq, packetsize, &written);
+    if ((code != CURLE_OK) || (written != packetsize)) {
+      failf(data, "Failed to send SOCKS4 connect request.");
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    packetsize = 8; /* receive data size */
+
+    /* Receive response */
+    result = blockread_all(conn, sock, (char *)socksreq, packetsize,
+                           &actualread, timeout);
+    if ((result != CURLE_OK) || (actualread != packetsize)) {
+      failf(data, "Failed to receive SOCKS4 connect request ack.");
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    /*
+     * Response format
+     *
+     *     +----+----+----+----+----+----+----+----+
+     *     | VN | CD | DSTPORT |      DSTIP        |
+     *     +----+----+----+----+----+----+----+----+
+     * # of bytes:  1    1      2              4
+     *
+     * VN is the version of the reply code and should be 0. CD is the result
+     * code with one of the following values:
+     *
+     * 90: request granted
+     * 91: request rejected or failed
+     * 92: request rejected because SOCKS server cannot connect to
+     *     identd on the client
+     * 93: request rejected because the client program and identd
+     *     report different user-ids
+     */
+
+    /* wrong version ? */
+    if (socksreq[0] != 0) {
+      failf(data,
+            "SOCKS4 reply has wrong version, version should be 4.");
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    /* Result */
+    switch(socksreq[1])
+    {
+    case 90:
+      infof(data, "SOCKS4 request granted.\n");
+      break;
+    case 91:
+      failf(data,
+            "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
+            ", request rejected or failed.",
+            (unsigned char)socksreq[4], (unsigned char)socksreq[5],
+            (unsigned char)socksreq[6], (unsigned char)socksreq[7],
+            (unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
+            socksreq[1]);
+      return CURLE_COULDNT_CONNECT;
+    case 92:
+      failf(data,
+            "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
+            ", request rejected because SOCKS server cannot connect to "
+            "identd on the client.",
+            (unsigned char)socksreq[4], (unsigned char)socksreq[5],
+            (unsigned char)socksreq[6], (unsigned char)socksreq[7],
+            (unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
+            socksreq[1]);
+      return CURLE_COULDNT_CONNECT;
+    case 93:
+      failf(data,
+            "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
+            ", request rejected because the client program and identd "
+            "report different user-ids.",
+            (unsigned char)socksreq[4], (unsigned char)socksreq[5],
+            (unsigned char)socksreq[6], (unsigned char)socksreq[7],
+            (unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
+            socksreq[1]);
+      return CURLE_COULDNT_CONNECT;
+    default:
+      failf(data,
+            "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
+            ", Unknown.",
+            (unsigned char)socksreq[4], (unsigned char)socksreq[5],
+            (unsigned char)socksreq[6], (unsigned char)socksreq[7],
+            (unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
+            socksreq[1]);
+      return CURLE_COULDNT_CONNECT;
+    }
+  }
+
+  Curl_nonblock(sock, TRUE);
+
+  return CURLE_OK; /* Proxy was successful! */
+}
+
+/*
+ * This function logs in to a SOCKS5 proxy and sends the specifics to the final
+ * destination server.
+ */
+CURLcode Curl_SOCKS5(const char *proxy_name,
+                     const char *proxy_password,
+                     struct connectdata *conn)
+{
+  /*
+    According to the RFC1928, section "6.  Replies". This is what a SOCK5
+    replies:
+
+        +----+-----+-------+------+----------+----------+
+        |VER | REP |  RSV  | ATYP | BND.ADDR | BND.PORT |
+        +----+-----+-------+------+----------+----------+
+        | 1  |  1  | X'00' |  1   | Variable |    2     |
+        +----+-----+-------+------+----------+----------+
+
+    Where:
+
+    o  VER    protocol version: X'05'
+    o  REP    Reply field:
+    o  X'00' succeeded
+  */
+
+  unsigned char socksreq[600]; /* room for large user/pw (255 max each) */
+  ssize_t actualread;
+  ssize_t written;
+  int result;
+  CURLcode code;
+  curl_socket_t sock = conn->sock[FIRSTSOCKET];
+  struct SessionHandle *data = conn->data;
+  long timeout;
+
+  /* get timeout */
+  if(data->set.timeout && data->set.connecttimeout) {
+    if (data->set.timeout < data->set.connecttimeout)
+      timeout = data->set.timeout*1000;
+    else
+      timeout = data->set.connecttimeout*1000;
+  }
+  else if(data->set.timeout)
+    timeout = data->set.timeout*1000;
+  else if(data->set.connecttimeout)
+    timeout = data->set.connecttimeout*1000;
+  else
+    timeout = DEFAULT_CONNECT_TIMEOUT;
+
+  Curl_nonblock(sock, TRUE);
+
+  /* wait until socket gets connected */
+  result = Curl_select(CURL_SOCKET_BAD, sock, (int)timeout);
+
+  if(-1 == result) {
+    failf(conn->data, "SOCKS5: no connection here");
+    return CURLE_COULDNT_CONNECT;
+  }
+  else if(0 == result) {
+    failf(conn->data, "SOCKS5: connection timeout");
+    return CURLE_OPERATION_TIMEDOUT;
+  }
+
+  if(result & CSELECT_ERR) {
+    failf(conn->data, "SOCKS5: error occured during connection");
+    return CURLE_COULDNT_CONNECT;
+  }
+
+  socksreq[0] = 5; /* version */
+  socksreq[1] = (char)(proxy_name ? 2 : 1); /* number of methods (below) */
+  socksreq[2] = 0; /* no authentication */
+  socksreq[3] = 2; /* username/password */
+
+  Curl_nonblock(sock, FALSE);
+
+  code = Curl_write(conn, sock, (char *)socksreq, (2 + (int)socksreq[1]),
+                      &written);
+  if ((code != CURLE_OK) || (written != (2 + (int)socksreq[1]))) {
+    failf(data, "Unable to send initial SOCKS5 request.");
+    return CURLE_COULDNT_CONNECT;
+  }
+
+  Curl_nonblock(sock, TRUE);
+
+  result = Curl_select(sock, CURL_SOCKET_BAD, (int)timeout);
+
+  if(-1 == result) {
+    failf(conn->data, "SOCKS5 nothing to read");
+    return CURLE_COULDNT_CONNECT;
+  }
+  else if(0 == result) {
+    failf(conn->data, "SOCKS5 read timeout");
+    return CURLE_OPERATION_TIMEDOUT;
+  }
+
+  if(result & CSELECT_ERR) {
+    failf(conn->data, "SOCKS5 read error occured");
+    return CURLE_RECV_ERROR;
+  }
+
+  Curl_nonblock(sock, FALSE);
+
+  result=blockread_all(conn, sock, (char *)socksreq, 2, &actualread, timeout);
+  if ((result != CURLE_OK) || (actualread != 2)) {
+    failf(data, "Unable to receive initial SOCKS5 response.");
+    return CURLE_COULDNT_CONNECT;
+  }
+
+  if (socksreq[0] != 5) {
+    failf(data, "Received invalid version in initial SOCKS5 response.");
+    return CURLE_COULDNT_CONNECT;
+  }
+  if (socksreq[1] == 0) {
+    /* Nothing to do, no authentication needed */
+    ;
+  }
+  else if (socksreq[1] == 2) {
+    /* Needs user name and password */
+    size_t userlen, pwlen;
+    int len;
+    if(proxy_name && proxy_password) {
+      userlen = strlen(proxy_name);
+      pwlen = proxy_password?strlen(proxy_password):0;
+    }
+    else {
+      userlen = 0;
+      pwlen = 0;
+    }
+
+    /*   username/password request looks like
+     * +----+------+----------+------+----------+
+     * |VER | ULEN |  UNAME   | PLEN |  PASSWD  |
+     * +----+------+----------+------+----------+
+     * | 1  |  1   | 1 to 255 |  1   | 1 to 255 |
+     * +----+------+----------+------+----------+
+     */
+    len = 0;
+    socksreq[len++] = 1;    /* username/pw subnegotiation version */
+    socksreq[len++] = (char) userlen;
+    memcpy(socksreq + len, proxy_name, (int) userlen);
+    len += userlen;
+    socksreq[len++] = (char) pwlen;
+    memcpy(socksreq + len, proxy_password, (int) pwlen);
+    len += pwlen;
+
+    code = Curl_write(conn, sock, (char *)socksreq, len, &written);
+    if ((code != CURLE_OK) || (len != written)) {
+      failf(data, "Failed to send SOCKS5 sub-negotiation request.");
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    result=blockread_all(conn, sock, (char *)socksreq, 2, &actualread,
+                         timeout);
+    if ((result != CURLE_OK) || (actualread != 2)) {
+      failf(data, "Unable to receive SOCKS5 sub-negotiation response.");
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    /* ignore the first (VER) byte */
+    if (socksreq[1] != 0) { /* status */
+      failf(data, "User was rejected by the SOCKS5 server (%d %d).",
+            socksreq[0], socksreq[1]);
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    /* Everything is good so far, user was authenticated! */
+  }
+  else {
+    /* error */
+    if (socksreq[1] == 1) {
+      failf(data,
+            "SOCKS5 GSSAPI per-message authentication is not supported.");
+      return CURLE_COULDNT_CONNECT;
+    }
+    else if (socksreq[1] == 255) {
+      if (!proxy_name || !*proxy_name) {
+        failf(data,
+              "No authentication method was acceptable. (It is quite likely"
+              " that the SOCKS5 server wanted a username/password, since none"
+              " was supplied to the server on this connection.)");
+      }
+      else {
+        failf(data, "No authentication method was acceptable.");
+      }
+      return CURLE_COULDNT_CONNECT;
+    }
+    else {
+      failf(data,
+            "Undocumented SOCKS5 mode attempted to be used by server.");
+      return CURLE_COULDNT_CONNECT;
+    }
+  }
+
+  /* Authentication is complete, now specify destination to the proxy */
+  socksreq[0] = 5; /* version (SOCKS5) */
+  socksreq[1] = 1; /* connect */
+  socksreq[2] = 0; /* must be zero */
+  socksreq[3] = 1; /* IPv4 = 1 */
+
+  {
+    struct Curl_dns_entry *dns;
+    Curl_addrinfo *hp=NULL;
+    int rc = Curl_resolv(conn, conn->host.name, (int)conn->remote_port, &dns);
+
+    if(rc == CURLRESOLV_ERROR)
+      return CURLE_COULDNT_RESOLVE_HOST;
+
+    if(rc == CURLRESOLV_PENDING)
+      /* this requires that we're in "wait for resolve" state */
+      rc = Curl_wait_for_resolv(conn, &dns);
+
+    /*
+     * We cannot use 'hostent' as a struct that Curl_resolv() returns.  It
+     * returns a Curl_addrinfo pointer that may not always look the same.
+     */
+    if(dns)
+      hp=dns->addr;
+    if (hp) {
+      char buf[64];
+      unsigned short ip[4];
+      Curl_printable_address(hp, buf, sizeof(buf));
+
+      if(4 == sscanf( buf, "%hu.%hu.%hu.%hu",
+                      &ip[0], &ip[1], &ip[2], &ip[3])) {
+        socksreq[4] = (unsigned char)ip[0];
+        socksreq[5] = (unsigned char)ip[1];
+        socksreq[6] = (unsigned char)ip[2];
+        socksreq[7] = (unsigned char)ip[3];
+      }
+      else
+        hp = NULL; /* fail! */
+
+      Curl_resolv_unlock(data, dns); /* not used anymore from now on */
+    }
+    if(!hp) {
+      failf(data, "Failed to resolve \"%s\" for SOCKS5 connect.",
+            conn->host.name);
+      return CURLE_COULDNT_RESOLVE_HOST;
+    }
+  }
+
+  *((unsigned short*)&socksreq[8]) = htons(conn->remote_port);
+
+  {
+    const int packetsize = 10;
+
+    code = Curl_write(conn, sock, (char *)socksreq, packetsize, &written);
+    if ((code != CURLE_OK) || (written != packetsize)) {
+      failf(data, "Failed to send SOCKS5 connect request.");
+      return 1;
+    }
+
+    result = blockread_all(conn, sock, (char *)socksreq, packetsize,
+                           &actualread, timeout);
+    if ((result != CURLE_OK) || (actualread != packetsize)) {
+      failf(data, "Failed to receive SOCKS5 connect request ack.");
+      return CURLE_COULDNT_CONNECT;
+    }
+
+    if (socksreq[0] != 5) { /* version */
+      failf(data,
+            "SOCKS5 reply has wrong version, version should be 5.");
+      return CURLE_COULDNT_CONNECT;
+    }
+    if (socksreq[1] != 0) { /* Anything besides 0 is an error */
+        failf(data,
+              "Can't complete SOCKS5 connection to %d.%d.%d.%d:%d. (%d)",
+              (unsigned char)socksreq[4], (unsigned char)socksreq[5],
+              (unsigned char)socksreq[6], (unsigned char)socksreq[7],
+              (unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
+              socksreq[1]);
+        return CURLE_COULDNT_CONNECT;
+    }
+  }
+
+  Curl_nonblock(sock, TRUE);
+  return CURLE_OK; /* Proxy was successful! */
+}