Switch the DPI framework from Unix sockets to Internet sockets

Initially meant for MINIX, but in the process several bugs were fixed,
the code restructured, added more error handling and improved in general.
In the future we may go back to UDS, but the cleanup gains will remain.

1 files changed, 131 insertions, 167 deletions

diff --git a/src/IO/dpi.c b/src/IO/dpi.c
index 7d5b550c..6f1c0a97 100644
--- a/src/IO/dpi.c
+++ b/src/IO/dpi.c
@@ -24,6 +24,7 @@
 #include <string.h>
 #include <stdio.h>
 #include <errno.h>           /* for errno */
+#include <fcntl.h>
 
 #include <sys/socket.h>
 #include <sys/un.h>
@@ -335,76 +336,57 @@ static int Dpi_start_dpid(void)
 }
 
 /*
- * Make a connection test for a UDS.
- * Return: 0 OK, 1 Not working.
+ * Read dpid's communication keys from its saved file.
+ * Return value: 1 on success, -1 on error.
  */
-static int Dpi_check_uds(char *uds_name)
+static int Dpi_read_comm_keys(int *port)
 {
-   struct sockaddr_un pun;
-   int SockFD, ret = 1;
-
-   if (access(uds_name, W_OK) == 0) {
-      /* socket connection test */
-      memset(&pun, 0, sizeof(struct sockaddr_un));
-      pun.sun_family = AF_LOCAL;
-      strncpy(pun.sun_path, uds_name, sizeof (pun.sun_path));
-
-      if ((SockFD = socket(AF_LOCAL, SOCK_STREAM, 0)) == -1 ||
-          connect(SockFD, (struct sockaddr *) &pun, D_SUN_LEN(&pun)) == -1) {
-         MSG("Dpi_check_uds: %s %s\n", dStrerror(errno), uds_name);
-      } else {
-         Dpi_close_fd(SockFD);
-         ret = 0;
-      }
+   FILE *In;
+   char *fname, *rcline = NULL;
+   int ret = -1;
+
+   fname = dStrconcat(dGethomedir(), "/.dillo/dpid_comm_keys", NULL);
+   if ((In = fopen(fname, "r")) == NULL) {
+      MSG_ERR("[Dpi_read_comm_keys] %s\n", dStrerror(errno));
+   } else if ((rcline = dGetline(In)) == NULL) {
+      MSG_ERR("[Dpi_read_comm_keys] empty file: %s\n", fname);
+   } else {
+      *port = strtol(rcline, NULL, 10);
+      ret = 1;
    }
+   dFree(rcline);
+   dFree(fname);
+
    return ret;
 }
 
 /*
- * Return the directory where the UDS are in,
- * NULL if it can't be found.
+ * Make a connection test for a IDS.
+ * Return: 1 OK, -1 Not working.
  */
-static char *Dpi_get_dpid_uds_dir(void)
+static int Dpi_check_dpid_ids()
 {
-   FILE *in;
-   char *saved_name_filename;    /*  :)  */
-   char buf[256], *dpid_uds_dir, *p = NULL, *nl;
-
-   saved_name_filename =
-      dStrconcat(dGethomedir(), "/.dillo/dpi_socket_dir", NULL);
-   in = fopen(saved_name_filename, "r");
-   dFree(saved_name_filename);
-
-   if (in != NULL) {
-      dpid_uds_dir = fgets(buf, sizeof(buf), in);
-      fclose(in);
-      if (dpid_uds_dir) {
-         if ((nl = strchr(dpid_uds_dir, '\n'))) {
-            *nl = 0;
-         }
-         if (access(dpid_uds_dir, F_OK) == 0) {
-            p = dStrdup(dpid_uds_dir);
-            _MSG("Dpi_get_dpid_uds_dir:: %s\n", p);
-         }
+   struct sockaddr_in sin;
+   const socklen_t sin_sz = sizeof(sin);
+   int sock_fd, dpid_port, ret = -1;
+
+   /* socket connection test */
+   memset(&sin, 0, sizeof(sin));
+   sin.sin_family = AF_INET;
+   sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+
+   if (Dpi_read_comm_keys(&dpid_port) != -1) {
+      sin.sin_port = htons(dpid_port);
+      if ((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
+         MSG("Dpi_check_dpid_ids: sock_fd=%d %s\n", sock_fd, dStrerror(errno));
+      } else if (connect(sock_fd, (struct sockaddr *)&sin, sin_sz) == -1) {
+         MSG("Dpi_check_dpid_ids: %s\n", dStrerror(errno));
+      } else {
+         Dpi_close_fd(sock_fd);
+         ret = 1;
       }
    }
-
-   _MSG("Dpi_get_dpid_uds_dir: %s \n", dStrerror(errno));
-   return p;
-}
-
-/*
- * Return the dpid's UDS name, NULL on failure.
- */
-static char *Dpi_get_dpid_uds_name(void)
-{
-   char *dpid_uds_dir, *dpid_uds_name = NULL;
-
-   if ((dpid_uds_dir = Dpi_get_dpid_uds_dir()) != NULL)
-      dpid_uds_name= dStrconcat(dpid_uds_dir, "/", "dpid.srs", NULL);
-
-   dFree(dpid_uds_dir);
-   return dpid_uds_name;
+   return ret;
 }
 
 /*
@@ -414,20 +396,16 @@ static char *Dpi_get_dpid_uds_name(void)
 static int Dpi_check_dpid(int num_tries)
 {
    static int starting = 0;
-   char *dpid_uds_name;
    int check_st = 1, ret = 2;
 
-   if ((dpid_uds_name = Dpi_get_dpid_uds_name()))
-      check_st = Dpi_check_uds(dpid_uds_name);
-
-   _MSG("Dpi_check_dpid: dpid_uds_name=%s, check_st=%d\n",
-        dpid_uds_name, check_st);
+   check_st = Dpi_check_dpid_ids();
+   MSG("Dpi_check_dpid: check_st=%d\n", check_st);
 
-   if (check_st == 0) {
+   if (check_st == 1) {
       /* connection test with dpi server passed */
       starting = 0;
       ret = 0;
-   } else if (!dpid_uds_name || check_st) {
+   } else {
       if (!starting) {
          /* start dpid */
          if (Dpi_start_dpid() == 0) {
@@ -435,6 +413,7 @@ static int Dpi_check_dpid(int num_tries)
             ret = 1;
          }
       } else if (++starting < num_tries) {
+         /* starting */
          ret = 1;
       } else {
          /* we waited too much, report an error... */
@@ -442,7 +421,6 @@ static int Dpi_check_dpid(int num_tries)
       }
    }
 
-   dFree(dpid_uds_name);
    _MSG("Dpi_check_dpid:: %s\n",
         (ret == 0) ? "OK" : (ret == 1 ? "EAGAIN" : "ERROR"));
    return ret;
@@ -466,59 +444,69 @@ static int Dpi_blocking_start_dpid(void)
 }
 
 /*
- * Return the UDS name of a dpi server.
+ * Return the dpi server's port number, or -1 on error.
  * (A query is sent to dpid and then its answer parsed)
  * note: as the available servers and/or the dpi socket directory can
  *       change at any time, we'll ask each time. If someday we find
  *       that connecting each time significantly degrades performance,
  *       an optimized approach can be tried.
+ * TODO: here we should use the credentials in ~/.dillo/dpid_comm_keys
+ *       (dpid port and password).
  */
-static char *Dpi_get_server_uds_name(const char *server_name)
+int Dpi_get_server_port(const char *server_name)
 {
-   char *dpid_uds_dir, *dpid_uds_name = NULL,
-         *server_uds_name = NULL;
-   int st;
-
-   dReturn_val_if_fail (server_name != NULL, NULL);
-   _MSG("Dpi_get_server_uds_name:: server_name = [%s]\n", server_name);
-
-   dpid_uds_dir = Dpi_get_dpid_uds_dir();
-   if (dpid_uds_dir) {
-      struct sockaddr_un dpid;
-      int sock, req_sz, rdlen;
-      char buf[128], *cmd, *request, *rply;
-      size_t buflen;
-
-      /* Get the server's uds name from dpid */
-      sock = socket(AF_LOCAL, SOCK_STREAM, 0);
-      dpid.sun_family = AF_LOCAL;
-      dpid_uds_name = dStrconcat(dpid_uds_dir, "/", "dpid.srs", NULL);
-      _MSG("dpid_uds_name = [%s]\n", dpid_uds_name);
-      strncpy(dpid.sun_path, dpid_uds_name, sizeof(dpid.sun_path));
-
-      if (connect(sock, (struct sockaddr *) &dpid, D_SUN_LEN(&dpid)) == -1)
-         perror("connect");
-      /* ask dpid to check the server plugin and send its UDS name back */
+   int sock_fd, req_sz, rdlen, dpi_port;
+   int st, dpid_port, ret = -1, ok = 0;
+   struct sockaddr_in sin;
+   char buf[128], *cmd, *request, *rply = NULL, *port_str;
+   size_t buflen;
+   socklen_t sin_sz;
+
+   dReturn_val_if_fail (server_name != NULL, ret);
+   _MSG("Dpi_get_server_port:: server_name = [%s]\n", server_name);
+
+   /* Read dpid's port from saved file */
+   if (Dpi_read_comm_keys(&dpid_port) != -1) {
+      ok = 1;
+   }
+   if (ok) {
+      /* Connect a socket with dpid */
+      sin_sz = sizeof(sin);
+      memset(&sin, 0, sizeof(sin));
+      sin.sin_family = AF_INET;
+      sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+      sin.sin_port = htons(dpid_port);
+      if ((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1 ||
+          connect(sock_fd, (struct sockaddr *)&sin, sin_sz) == -1) {
+         MSG("Dpi_get_server_port: %s\n", dStrerror(errno));
+         ok = 0;
+      }
+   }
+   if (ok) {
+      /* ask dpid to check the dpi and send its port number back */
       request = a_Dpip_build_cmd("cmd=%s msg=%s", "check_server", server_name);
       _MSG("[%s]\n", request);
-      do
-         st = write(sock, request, strlen(request));
-      while (st < 0 && errno == EINTR);
-      if (st < 0 && errno != EINTR)
-         perror("writing request");
+      do {
+         st = write(sock_fd, request, strlen(request));
+      } while (st < 0 && errno == EINTR);
+      if (st < 0 && errno != EINTR) {
+         MSG("Dpi_get_server_port: %s\n", dStrerror(errno));
+         ok = 0;
+      }
       dFree(request);
-      shutdown(sock, 1); /* signals no more writes to dpid */
-
+      shutdown(sock_fd, 1); /* signals no more writes to dpid */
+   }
+   if (ok) {
       /* Get the reply */
-      rply = NULL;
       buf[0] = '\0';
       buflen = sizeof(buf)/sizeof(buf[0]);
-      for (req_sz = 0; (rdlen = read(sock, buf, buflen)) != 0;
+      for (req_sz = 0; (rdlen = read(sock_fd, buf, buflen)) != 0;
            req_sz += rdlen) {
          if (rdlen == -1 && errno == EINTR)
                continue;
          if (rdlen == -1) {
-            perror(" ** Dpi_get_server_uds_name **");
+            MSG("Dpi_get_server_port: %s\n", dStrerror(errno));
+            ok = 0;
             break;
          }
          rply = dRealloc(rply, (uint_t)(req_sz + rdlen + 1));
@@ -526,69 +514,70 @@ static char *Dpi_get_server_uds_name(const char *server_name)
             rply[0] = '\0';
          strncat(rply, buf, (size_t)rdlen);
       }
-      Dpi_close_fd(sock);
-      _MSG("rply = [%s]\n", rply);
-
-      /* Parse reply */
+      Dpi_close_fd(sock_fd);
       if (rdlen == 0 && rply) {
-         cmd = a_Dpip_get_attr(rply, "cmd");
-         if (strcmp(cmd, "send_data") == 0)
-            server_uds_name = a_Dpip_get_attr(rply, "msg");
-         dFree(cmd);
-         dFree(rply);
+         _MSG("rply = [%s]\n", rply);
+         ok = 1;
       }
    }
-   dFree(dpid_uds_dir);
-   dFree(dpid_uds_name);
-   _MSG("Dpi_get_server_uds_name:: %s\n", server_uds_name);
-   return server_uds_name;
+   if (ok) {
+      /* Parse reply */
+      cmd = a_Dpip_get_attr(rply, "cmd");
+      if (strcmp(cmd, "send_data") == 0) {
+         port_str = a_Dpip_get_attr(rply, "msg");
+         MSG("Dpi_get_server_port: rply=%s\n", rply);
+         MSG("Dpi_get_server_port: port_str=%s\n", port_str);
+         dpi_port = strtol(port_str, NULL, 10);
+         dFree(port_str);
+         ok = 1;
+      }
+      dFree(cmd);
+   }
+   dFree(rply);
+
+   return ok ? dpi_port : -1;
 }
 
 
 /*
  * Connect a socket to a dpi server and return the socket's FD.
- * We have to ask 'dpid' (dpi daemon) for the UDS of the target dpi server.
+ * We have to ask 'dpid' (dpi daemon) for the port of the target dpi server.
  * Once we have it, then the proper file descriptor is returned (-1 on error).
  */
 static int Dpi_connect_socket(const char *server_name, int retry)
 {
-   char *server_uds_name;
-   struct sockaddr_un pun;
-   int SockFD, err;
+   struct sockaddr_in sin;
+   int sock_fd, err, dpi_port;
 
-   /* Query dpid for the UDS name for this server */
-   server_uds_name = Dpi_get_server_uds_name(server_name);
-   _MSG("server_uds_name = [%s]\n", server_uds_name);
-
-   if (access(server_uds_name, F_OK) != 0) {
-      MSG("server socket was NOT found\n");
+   /* Query dpid for the port number for this server */
+   if ((dpi_port = Dpi_get_server_port(server_name)) == -1) {
+      MSG("Dpi_connect_socket:: can't get port number for %s\n", server_name);
       return -1;
    }
+   MSG("Dpi_connect_socket: server=%s port=%d\n", server_name, dpi_port);
 
    /* connect with this server's socket */
-   memset(&pun, 0, sizeof(struct sockaddr_un));
-   pun.sun_family = AF_LOCAL;
-   strncpy(pun.sun_path, server_uds_name, sizeof (pun.sun_path));
-   dFree(server_uds_name);
+   memset(&sin, 0, sizeof(sin));
+   sin.sin_family = AF_INET;
+   sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+   sin.sin_port = htons(dpi_port);
 
-   if ((SockFD = socket(AF_LOCAL, SOCK_STREAM, 0)) == -1)
+   if ((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
       perror("[dpi::socket]");
-   else if (connect(SockFD, (void*)&pun, D_SUN_LEN(&pun)) == -1) {
+   } else if (connect(sock_fd, (void*)&sin, sizeof(sin)) == -1) {
       err = errno;
-      SockFD = -1;
+      sock_fd = -1;
       MSG("[dpi::connect] errno:%d %s\n", errno, dStrerror(errno));
       if (retry) {
          switch (err) {
             case ECONNREFUSED: case EBADF: case ENOTSOCK: case EADDRNOTAVAIL:
-               /* the server may crash and its socket name survive */
-               unlink(pun.sun_path);
-               SockFD = Dpi_connect_socket(server_name, FALSE);
+               sock_fd = Dpi_connect_socket(server_name, FALSE);
                break;
          }
       }
    }
 
-   return SockFD;
+   return sock_fd;
 }
 
 
@@ -707,38 +696,13 @@ void a_Dpi_ccc(int Op, int Branch, int Dir, ChainLink *Info,
    }
 }
 
-/*! Send DpiBye to dpid
- * Note: currently disabled. Maybe it'd be better to have a
- * dpid_idle_timeout variable in the config file.
+/*! Let dpid know dillo is no longer running.
+ * Note: currently disabled. It may serve to let the cookies dpi know
+ * when to expire session cookies.
  */
-void a_Dpi_bye_dpid()
+void a_Dpi_dillo_exit()
 {
-   char *DpiBye_cmd;
-   struct sockaddr_un sa;
-   size_t sun_path_len, addr_len;
-   char *srs_name;
-   int new_socket;
-
-   srs_name = Dpi_get_dpid_uds_name();
-   sun_path_len = sizeof(sa.sun_path);
-
-   sa.sun_family = AF_LOCAL;
 
-   if ((new_socket = socket(AF_LOCAL, SOCK_STREAM, 0)) == -1) {
-      MSG("a_Dpi_bye_dpid: %s\n", dStrerror(errno));
-   }
-   strncpy(sa.sun_path, srs_name, sizeof (sa.sun_path));
-   addr_len = D_SUN_LEN(&sa);
-   if (connect(new_socket, (struct sockaddr *) &sa, addr_len) == -1) {
-      MSG("a_Dpi_bye_dpid: %s\n", dStrerror(errno));
-      MSG("%s\n", sa.sun_path);
-   }
-   DpiBye_cmd = a_Dpip_build_cmd("cmd=%s", "DpiBye");
-   if (write(new_socket, DpiBye_cmd, strlen(DpiBye_cmd)) !=
-       (ssize_t) strlen(DpiBye_cmd))
-      MSG_WARN("Failed to send DpiBye\n");
-   dFree(DpiBye_cmd);
-   Dpi_close_fd(new_socket);
 }