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.

5 files changed, 191 insertions, 269 deletions

diff --git a/dpid/dpid.c b/dpid/dpid.c
index 8d325694..70f59a62 100644
--- a/dpid/dpid.c
+++ b/dpid/dpid.c
@@ -19,11 +19,13 @@
  * Main functions to set-up dpi information and to initialise sockets
  */
 #include <errno.h>
-#include <stdlib.h>   /* for exit */
-#include <fcntl.h>    /* for F_SETFD, F_GETFD, FD_CLOEXEC */
+#include <stdlib.h>             /* for exit */
+#include <fcntl.h>              /* for F_SETFD, F_GETFD, FD_CLOEXEC */
 
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include <sys/socket.h>
+
 #include <unistd.h>
 #include "dpid_common.h"
 #include "dpid.h"
@@ -37,70 +39,11 @@
 
 volatile sig_atomic_t caught_sigchld = 0;
 
-/*! Return the basename of a filename
- */
-static char *get_basename(char *filename)
-{
-   char *p;
-
-   if (filename && (p = strrchr(filename, '/'))) {
-      filename = p + 1;
-   }
-   return filename;
-}
-
-/*! Close and remove the sockets in the
- * given dpi attribute list
- */
-void rm_dpi_sockets(struct dp *dpi_attr_list, int numdpis)
-{
-   int i;
-
-   for (i = 0; i < numdpis; i++) {
-      a_Misc_close_fd(dpi_attr_list[i].socket);
-      (void) unlink(dpi_attr_list[i].sockpath);
-   }
-}
-
-/*! Close and remove inactive dpi sockets
- * \Return
- * Number of active dpis.
+/*! Remove UDS filenames 
  */
-int rm_inactive_dpi_sockets(struct dp *dpi_attr_list, int numdpis)
+void cleanup()
 {
-   int i, active = 0;
 
-   for (i = 0; i < numdpis; i++) {
-      if (dpi_attr_list[i].pid == 1) {
-         a_Misc_close_fd(dpi_attr_list[i].socket);
-         (void) unlink(dpi_attr_list[i].sockpath);
-      } else
-         active++;
-   }
-   return (active);
-}
-
-/*! Remove sockets
- */
-void cleanup(char *socket_dir)
-{
-   DIR *dir;
-   struct dirent *dir_entry = NULL;
-   char *sockpath;
-
-   dir = opendir(socket_dir);
-   if (dir == NULL) {
-      ERRMSG("cleanup", "opendir", errno);
-      return;
-   }
-   while ( (dir_entry = readdir(dir)) != NULL ) {
-      if (dir_entry->d_name[0] == '.')
-         continue;
-      sockpath = dStrconcat(socket_dir, "/", dir_entry->d_name, NULL);
-      unlink(sockpath);
-      dFree(sockpath);
-   }
-   closedir(dir);
 }
 
 /*! Free memory used to describe
@@ -116,10 +59,6 @@ void free_dpi_attr(struct dp *dpi_attr)
       dFree(dpi_attr->path);
       dpi_attr->path = NULL;
    }
-   if (dpi_attr->sockpath != NULL) {
-      dFree(dpi_attr->sockpath);
-      dpi_attr->sockpath = NULL;
-   }
 }
 
 /*! Free memory used by the plugin list
@@ -306,7 +245,7 @@ int get_dpi_attr(char *dpi_dir, char *service, struct dp *dpi_attr)
                dpi_attr->path =
                   dStrconcat(service_dir, "/", dir_entry->d_name, NULL);
                dpi_attr->id = dStrdup(service);
-               dpi_attr->sockpath = NULL;
+               dpi_attr->port = 0;
                dpi_attr->pid = 1;
                if (strstr(dpi_attr->path, ".filter") != NULL)
                   dpi_attr->filter = 1;
@@ -573,127 +512,122 @@ int fill_services_list(struct dp *attlist, int numdpis, Dlist **services_list)
    return (dList_length(*services_list));
 }
 
-/*! Initialise the service request socket
- * \Return:
- * \li Number of sockets (1 == success)
+/*! Bind a socket port on localhost. Try to be close to base_port.
+ * \Return
+ * \li listening socket file descriptor on success
  * \li -1 on failure
  */
-int init_srs_socket(char *sockdir)
+int bind_socket_fd(int base_port, int *p_port)
 {
-   int retval = -1;
-   struct sockaddr_un srs_sa;
-   size_t sun_path_len;
-   socklen_t addr_sz;
+   int sock_fd, port;
+   struct sockaddr_in sin;
+   //size_t sock_buflen = 8192;
+   int ok = 0, last_port = base_port + 50;
 
-   srs_name = dStrconcat(sockdir, "/", SRS_NAME, NULL);
-   FD_ZERO(&sock_set);
+   if ((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
+      ERRMSG("bind_socket_fd", "socket", errno);
+      return (-1);              /* avoids nested ifs */
+   }
+   /* Set the socket FD to close on exec */
+   fcntl(sock_fd, F_SETFD, FD_CLOEXEC | fcntl(sock_fd, F_GETFD));
 
-   /* Initialise srs, service request socket on startup */
-   if ((srs = socket(AF_LOCAL, SOCK_STREAM, 0)) == -1) {
-      ERRMSG("init_srs_socket", "socket", errno);
-      return (retval);              /* avoids nesting ifs too deeply */
+   /* set some buffering to increase the transfer's speed */
+   //setsockopt(sock_fd, SOL_SOCKET, SO_SNDBUF,
+   //           &sock_buflen, (socklen_t)sizeof(sock_buflen));
+
+   memset(&sin, 0, sizeof(sin));
+   sin.sin_family = AF_INET;
+   sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+
+   /* Try to bind a port on localhost */
+   for (port = base_port; port <= last_port; ++port) {
+      sin.sin_port = htons(port);
+      if ((bind(sock_fd, (struct sockaddr *)&sin, sizeof(sin))) == -1) {
+         if (errno == EADDRINUSE || errno == EADDRNOTAVAIL)
+            continue;
+         ERRMSG("bind_socket_fd", "bind", errno);
+      } else if (listen(sock_fd, QUEUE) == -1) {
+         ERRMSG("bind_socket_fd", "listen", errno);
+      } else {
+         *p_port = port;
+         ok = 1;
+         break;
+      }
+   }
+   if (port > last_port) {
+      MSG_ERR("Hey! Can't find an available port from %d to %d\n",
+              base_port, last_port);
    }
-   /* Set srs to close on exec */
-   fcntl(srs, F_SETFD, FD_CLOEXEC | fcntl(srs, F_GETFD));
 
-   srs_sa.sun_family = AF_LOCAL;
+   return ok ? sock_fd : -1;
+}
 
-   sun_path_len = sizeof(srs_sa.sun_path);
-   if (strlen(srs_name) > sun_path_len) {
-      ERRMSG("init_srs_socket", "srs_name is too long", 0);
-      MSG_ERR("\n - it should be <= %lu chars", (ulong_t)sun_path_len);
-      MSG_ERR("\n - srs_name = %s\n", srs_name);
-      return(retval);
+/*! Save the current port in a file so dillo can find it.
+ * \Return:
+ * \li -1 on failure
+ */
+int save_comm_keys(int srs_port)
+{
+   int fd;
+   char *fname, ret = -1, port_str[16];
+
+   fname = dStrconcat(dGethomedir(), "/", dotDILLO_DPID_COMM_KEYS, NULL);
+   fd = open(fname, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
+   dFree(fname);
+   if (fd == -1) {
+      MSG("save_comm_keys: open %s\n", dStrerror(errno));
+   } else {
+      snprintf(port_str, 8, "%d\n", srs_port);
+      if (CKD_WRITE(fd, port_str) != -1)
+         ret = 1;
    }
-   strncpy(srs_sa.sun_path, srs_name, sun_path_len);
-   addr_sz = (socklen_t) D_SUN_LEN(&srs_sa);
 
-   if ((bind(srs, (struct sockaddr *) &srs_sa, addr_sz)) == -1) {
-      if (errno == EADDRINUSE) {
-         ERRMSG("init_srs_socket", "bind", errno);
-         MSG_ERR("srs_sa.sun_path = %s\n", srs_sa.sun_path);
-         dpi_errno = dpid_srs_addrinuse;
-      } else {
-         ERRMSG("init_srs_socket", "bind", errno);
-         MSG_ERR("srs_sa.sun_path = %s\n", srs_sa.sun_path);
+   return ret;
+}
+
+/*! Initialise the service request socket (IDS)
+ * \Return:
+ * \li Number of sockets (1 == success)
+ * \li -1 on failure
+ */
+int init_ids_srs_socket()
+{
+   int srs_port, ret = -1;
+
+   FD_ZERO(&sock_set);
+
+   if ((srs_fd = bind_socket_fd(DPID_BASE_PORT, &srs_port)) != -1) {
+      /* save port number */
+      if (save_comm_keys(srs_port) != -1) {
+         FD_SET(srs_fd, &sock_set);
+         ret = 1;
       }
-   } else if (chmod(srs_sa.sun_path, S_IRUSR | S_IWUSR) == -1) {
-      ERRMSG("init_srs_socket", "chmod", errno);
-      MSG_ERR("srs_sa.sun_path = %s\n", srs_sa.sun_path);
-   } else if (listen(srs, QUEUE) == -1) {
-      ERRMSG("init_srs_socket", "listen", errno);
-   } else {
-      retval = 1;
    }
 
-   FD_SET(srs, &sock_set);
-   return (retval);
+   return ret;
 }
 
-/*! Initialise a single dpi socket
+/*! Initialize a single dpi socket
  * \Return
  * \li 1 on success
  * \li -1 on failure
  */
-int init_dpi_socket(struct dp *dpi_attr, char *sockdir)
+int init_dpi_socket(struct dp *dpi_attr)
 {
-   int caught_error = 0, s;
-   char *dpi_nm;                /* pointer to basename in dpi_attr->path */
-   struct sockaddr_un sa;
-   size_t sp_len;
-   socklen_t addr_sz;
-   size_t sock_buflen = 8192;
-
-   sp_len = sizeof(sa.sun_path);
-   if ((s = socket(AF_LOCAL, SOCK_STREAM, 0)) == -1) {
-      ERRMSG("init_all_dpi_sockets", "socket", errno);
-      return (-1);              /* avoids nested ifs */
-   }
-   /* Set the socket FD to close on exec */
-   fcntl(s, F_SETFD, FD_CLOEXEC | fcntl(s, F_GETFD));
+   int s_fd, port, ret = -1;
 
-   /* set some buffering to increase the transfer's speed */
-   setsockopt(s, SOL_SOCKET, SO_SNDBUF,
-              &sock_buflen, (socklen_t)sizeof(sock_buflen));
-
-   dpi_attr->socket = s;
-   dpi_attr->sa.sun_family = AF_LOCAL;
-   dpi_nm = get_basename(dpi_attr->path);
-
-   dpi_attr->sockpath = dStrconcat(sockdir, "/", dpi_nm, "-XXXXXX", NULL);
-   a_Misc_mkfname(dpi_attr->sockpath);
-   if (strlen(dpi_attr->sockpath) > sp_len) {
-      ERRMSG("init_all_dpi_sockets", "socket path is too long", 0);
-      MSG_ERR("\n - it should be <= %lu chars", (ulong_t)sp_len);
-      MSG_ERR("\n - socket path = %s\n", dpi_attr->sockpath);
-      return(-1);
-   }
-   strncpy(dpi_attr->sa.sun_path, dpi_attr->sockpath, sp_len);
-   addr_sz = (socklen_t) D_SUN_LEN(&dpi_attr->sa);
-
-   if ((bind(s, (struct sockaddr *) &dpi_attr->sa, addr_sz)) == -1) {
-      ERRMSG("init_all_dpi_sockets", "bind", errno);
-      MSG_ERR("%s\n", dpi_attr->sa.sun_path);
-      caught_error = 1;
-   } else if (chmod(dpi_attr->sa.sun_path, S_IRUSR | S_IWUSR) == -1) {
-      ERRMSG("init_all_dpi_sockets", "chmod", errno);
-      MSG_ERR("%s\n", dpi_attr->sa.sun_path);
-      caught_error = 1;
-   } else if (listen(s, QUEUE) == -1) {
-      ERRMSG("init_all_dpi_sockets", "listen", errno);
-      caught_error = 1;
-   }
-
-   if (caught_error) {
-      return (-1);
-   } else {
-      FD_SET(s, &sock_set);
-      return (1);
+   if ((s_fd = bind_socket_fd(DPID_BASE_PORT, &port)) != -1) {
+      dpi_attr->sock_fd = s_fd;
+      dpi_attr->port = port;
+      FD_SET(s_fd, &sock_set);
+      ret = 1;
    }
+
+   return ret;
 }
 
 /*! Setup sockets for the plugins and add them to
- * to the set of sockets (sock_set) watched by select.
+ * the set of sockets (sock_set) watched by select.
  * \Return
  * \li Number of sockets on success
  * \li -1 on failure
@@ -702,17 +636,13 @@ int init_dpi_socket(struct dp *dpi_attr, char *sockdir)
  * \Uses
  * numdpis, srs, srs_name
  */
-int init_all_dpi_sockets(struct dp *dpi_attr_list, char *sockdir)
+int init_all_dpi_sockets(struct dp *dpi_attr_list)
 {
    int i;
-   struct sockaddr_un sa;
-   size_t sp_len;
-
-   sp_len = sizeof(sa.sun_path);
 
    /* Initialise sockets for each dpi */
    for (i = 0; i < numdpis; i++) {
-      if (init_dpi_socket(dpi_attr_list + i, sockdir) == -1)
+      if (init_dpi_socket(dpi_attr_list + i) == -1)
          return (-1);
       numsocks++;
    }
@@ -741,7 +671,7 @@ void handle_sigchld(void)
    for (i = 0; i < numdpis; i++) {
       if (waitpid(dpi_attr_list[i].pid, &status, WNOHANG) > 0) {
          dpi_attr_list[i].pid = 1;
-         FD_SET(dpi_attr_list[i].socket, &sock_set);
+         FD_SET(dpi_attr_list[i].sock_fd, &sock_set);
          numsocks++;
       }
    }
@@ -772,43 +702,34 @@ void est_dpi_sigchld(void)
 void stop_active_dpis(struct dp *dpi_attr_list, int numdpis)
 {
    static char *DpiBye_cmd = NULL;
-   int i, dpi_socket, rc;
-   struct sockaddr_un dpi_addr;
-   struct sockaddr_un sa;
-   size_t sun_path_len, addr_len;
+   int i, sock_fd;
+   struct sockaddr_in sin;
 
    if (!DpiBye_cmd)
       DpiBye_cmd = a_Dpip_build_cmd("cmd=%s", "DpiBye");
 
-   sun_path_len = sizeof(sa.sun_path);
-
-   dpi_addr.sun_family = AF_LOCAL;
+   memset(&sin, 0, sizeof(sin));
+   sin.sin_family = AF_INET;
+   sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 
    for (i = 0; i < numdpis; i++) {
       /* Skip inactive dpis and filters */
       if (dpi_attr_list[i].pid == 1 || dpi_attr_list[i].filter)
          continue;
 
-      if ((dpi_socket = socket(AF_LOCAL, SOCK_STREAM, 0)) == -1) {
+      if ((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
          ERRMSG("stop_active_dpis", "socket", errno);
+         continue;
       }
-      if (strlen(dpi_attr_list[i].sockpath) > sun_path_len) {
-         ERRMSG("stop_active_dpis", "socket path is too long", 0);
-         MSG_ERR("\n - it should be <= %lu chars",(ulong_t)sun_path_len);
-         MSG_ERR("\n - socket path = %s\n", dpi_attr_list[i].sockpath);
-      }
-      strncpy(dpi_addr.sun_path, dpi_attr_list[i].sockpath, sun_path_len);
-      addr_len = D_SUN_LEN(&dpi_addr);
-      if (connect(dpi_socket, (struct sockaddr *) &dpi_addr, addr_len) == -1) {
+      sin.sin_port = htons(dpi_attr_list[i].port);
+      if (connect(sock_fd, (struct sockaddr *)&sin, sizeof(sin)) == -1) {
          ERRMSG("stop_active_dpis", "connect", errno);
-         MSG_ERR("%s\n", dpi_addr.sun_path);
-      }
-      rc = write(dpi_socket, DpiBye_cmd, strlen(DpiBye_cmd));
-      if (rc == -1) {
+         MSG_ERR("%s\n", dpi_attr_list[i].path);
+      } else if (write(sock_fd, DpiBye_cmd, strlen(DpiBye_cmd)) == -1) {
          MSG("stop_active_dpis: Error on sending BYE command: %s\n",
              dStrerror(errno));
       }
-      a_Misc_close_fd(dpi_socket);
+      a_Misc_close_fd(sock_fd);
    }
 }
 
@@ -821,8 +742,8 @@ void ignore_dpi_sockets(struct dp *dpi_attr_list, int numdpis)
    int i;
 
    for (i = 0; i < numdpis; i++) {
-      FD_CLR(dpi_attr_list[i].socket, &sock_set);
-      a_Misc_close_fd(dpi_attr_list[i].socket);
+      FD_CLR(dpi_attr_list[i].sock_fd, &sock_set);
+      a_Misc_close_fd(dpi_attr_list[i].sock_fd);
    }
 }
 
@@ -833,20 +754,19 @@ void ignore_dpi_sockets(struct dp *dpi_attr_list, int numdpis)
  * \Return
  * Number of available dpis
  */
-int register_all_cmd(char *sockdir)
+int register_all_cmd()
 {
    stop_active_dpis(dpi_attr_list, numdpis);
-   rm_dpi_sockets(dpi_attr_list, numdpis);
    free_plugin_list(&dpi_attr_list, numdpis);
    free_services_list(services_list);
    services_list = NULL;
    numdpis = 0;
    numsocks = 1;                /* the srs socket */
    FD_ZERO(&sock_set);
-   FD_SET(srs, &sock_set);
+   FD_SET(srs_fd, &sock_set);
    numdpis = register_all(&dpi_attr_list);
    fill_services_list(dpi_attr_list, numdpis, &services_list);
-   numsocks = init_all_dpi_sockets(dpi_attr_list, sockdir);
+   numsocks = init_all_dpi_sockets(dpi_attr_list);
    return (numdpis);
 }
 
@@ -855,7 +775,7 @@ int register_all_cmd(char *sockdir)
  * \Return
  * message on success, NULL on failure
  */
-char *get_message(int sock, char *dpi_tag)
+char *get_message(int sock_fd, char *dpi_tag)
 {
    char *msg, *d_cmd;
 
@@ -864,7 +784,7 @@ char *get_message(int sock, char *dpi_tag)
       ERRMSG("get_message", "failed to parse msg", 0);
       d_cmd = a_Dpip_build_cmd("cmd=%s msg=%s",
                                "DpiError", "Failed to parse request");
-      (void) CKD_WRITE(sock, d_cmd);
+      (void) CKD_WRITE(sock_fd, d_cmd);
       dFree(d_cmd);
    }
    return (msg);
@@ -889,40 +809,30 @@ int service_match(const struct service *A, const char *B)
 }
 
 /*!
- * Send socket path that matches dpi_id to client
+ * Send socket port that matches dpi_id to client
  */
-void send_sockpath(int sock, char *dpi_tag, struct dp *dpi_attr_list)
+void send_sockport(int sock_fd, char *dpi_tag, struct dp *dpi_attr_list)
 {
    int i;
-   char *dpi_id;
-   char *d_cmd;
+   char *dpi_id, *d_cmd, port_str[16];
    struct service *serv;
 
-   dReturn_if_fail((dpi_id = get_message(sock, dpi_tag)) != NULL);
+   dReturn_if_fail((dpi_id = get_message(sock_fd, dpi_tag)) != NULL);
 
    serv = dList_find_custom(services_list,dpi_id,(dCompareFunc)service_match);
 
    if (serv == NULL || (i = serv->dp_index) == -1)
       for (i = 0; i < numdpis; i++)
          if (!strncmp(dpi_attr_list[i].id, dpi_id,
-        dpi_attr_list[i].id - strchr(dpi_attr_list[i].id, '.')))
+                      dpi_attr_list[i].id - strchr(dpi_attr_list[i].id, '.')))
             break;
 
    if (i < numdpis) {
       /* found */
-      if (access(dpi_attr_list[i].path, F_OK) == -1) {
-         ERRMSG("send_sockpath", "access", errno);
-         MSG_ERR(" - %s\n", dpi_attr_list[i].sockpath);
-         d_cmd = a_Dpip_build_cmd("cmd=%s msg=%s",
-                                  "DpiError", "Plugin currently unavailable");
-         (void) CKD_WRITE(sock, d_cmd);
-         dFree(d_cmd);
-      } else {
-         d_cmd = a_Dpip_build_cmd("cmd=%s msg=%s",
-                                  "send_data", dpi_attr_list[i].sockpath);
-         (void) CKD_WRITE(sock, d_cmd);
-         dFree(d_cmd);
-      }
+      snprintf(port_str, 8, "%d", dpi_attr_list[i].port);
+      d_cmd = a_Dpip_build_cmd("cmd=%s msg=%s", "send_data", port_str);
+      (void) CKD_WRITE(sock_fd, d_cmd);
+      dFree(d_cmd);
    }
 
    dFree(dpi_id);
diff --git a/dpid/dpid.h b/dpid/dpid.h
index 5c5aa3f8..7302356b 100644
--- a/dpid/dpid.h
+++ b/dpid/dpid.h
@@ -6,9 +6,10 @@
 #define DPID_H
 
 #include <sys/socket.h>
-#include <sys/select.h> /* for fd_set */
+#include <sys/select.h>   /* for fd_set */
 #include <sys/un.h>
-#include <signal.h>     /* for sig_atomic_t */
+#include <signal.h>       /* for sig_atomic_t */
+#include <netinet/in.h>   /* for ntohl, IPPORT_USERRESERVED and stuff */
 
 #include "d_size.h"
 
@@ -16,21 +17,22 @@
 #define PATH_LEN 50
 #define CMDLEN 20
 #define MSGLEN 50
+#define DPID_BASE_PORT (IPPORT_USERRESERVED + 20)
+
 /*! \TODO: Should read this from dillorc */
 #define SRS_NAME "dpid.srs"
 char *srs_name;
 
-/*! dpid service request socket */
-int srs;
+/*! dpid's service request socket file descriptor */
+int srs_fd;
 
 /*! plugin state information
  */
 struct dp {
    char *id;
    char *path;
-   char *sockpath;
-   int socket;
-   struct sockaddr_un sa;
+   int sock_fd;
+   int port;
    pid_t pid;
    int filter;
 };
@@ -62,9 +64,7 @@ extern volatile sig_atomic_t caught_sigchld;
 
 void rm_dpi_sockets(struct dp *dpi_attr_list, int numdpis);
 
-int rm_inactive_dpi_sockets(struct dp *dpi_attr_list, int numdpis);
-
-void cleanup(char *socket_dir);
+void cleanup();
 
 void free_dpi_attr(struct dp *dpi_attr);
 
@@ -82,11 +82,11 @@ int register_all(struct dp **attlist);
 
 int fill_services_list(struct dp *attlist, int numdpis, Dlist **services_list);
 
-int init_srs_socket(char *sockdir);
+int init_ids_srs_socket();
 
-int init_dpi_socket(struct dp *dpi_attr, char *sockdir);
+int init_dpi_socket(struct dp *dpi_attr);
 
-int init_all_dpi_sockets(struct dp *dpi_attr_list, char *sockdir);
+int init_all_dpi_sockets(struct dp *dpi_attr_list);
 
 void dpi_sigchld(int sig);
 
@@ -98,12 +98,12 @@ void stop_active_dpis(struct dp *dpi_attr_list, int numdpis);
 
 void ignore_dpi_sockets(struct dp *dpi_attr_list, int numdpis);
 
-int register_all_cmd(char *sockdir);
+int register_all_cmd();
 
 char *get_message(int sock, char *dpi_tag);
 
 int service_match(const struct service *A, const char *B);
 
-void send_sockpath(int sock, char * dpi_tag, struct dp *dpi_attr_list);
+void send_sockport(int sock_fd, char * dpi_tag, struct dp *dpi_attr_list);
 
 #endif
diff --git a/dpid/dpid_common.h b/dpid/dpid_common.h
index 5a792b04..65b8bc89 100644
--- a/dpid/dpid_common.h
+++ b/dpid/dpid_common.h
@@ -23,6 +23,8 @@
 
 #define dotDILLO_DPI ".dillo/dpi"
 #define dotDILLO_DPIDRC ".dillo/dpidrc"
+#define dotDILLO_DPID_COMM_KEYS ".dillo/dpid_comm_keys"
+
 #define ERRMSG(CALLER, CALLED, ERR)\
  errmsg(CALLER, CALLED, ERR, __FILE__, __LINE__)
 #define _ERRMSG(CALLER, CALLED, ERR)
diff --git a/dpid/dpidc b/dpid/dpidc
index 88b887cb..7f8bc0e6 100644
--- a/dpid/dpidc
+++ b/dpid/dpidc
@@ -7,14 +7,20 @@
 # stop: Stops dpid.
 
 use strict;
-use IO::Socket::UNIX;
+use IO::Socket::INET;
 
 # Get socket directory name
-open(DSD, "<$ENV{HOME}/.dillo/dpi_socket_dir");
-my $dir = <DSD>;
+#open(DSD, "<$ENV{HOME}/.dillo/dpi_socket_dir");
+#my $dir = <DSD>;
+#close(DSD);
+
+# Get dpid's listening port from saved file
+open(DSD, "<$ENV{HOME}/.dillo/dpid_comm_keys");
+my $port = <DSD>;
 close(DSD);
+print "Got: localhost:$port\n";
 
-my $socket = IO::Socket::UNIX->new(Peer => "$dir/dpid.srs", Type => SOCK_STREAM, Timeout => 1000 ) or die "new: $@";
+my $socket = IO::Socket::INET->new(Peer => "localhost:$port", Type => SOCK_STREAM, Timeout => 1000 ) or die "new: $@";
 
 $socket->autoflush(1);
 
@@ -23,7 +29,7 @@ my %dpi_command = (
         "stop" => "<dpi cmd='DpiBye' '>",
         );
 
-if ( exists($dpi_command{$ARGV[0]}) ) {
+if ( $#ARGV == 0 && exists($dpi_command{$ARGV[0]}) ) {
         print $socket $dpi_command{$ARGV[0]};
 } else {
         close($socket);
diff --git a/dpid/main.c b/dpid/main.c
index 7ecae76a..fcb11cef 100644
--- a/dpid/main.c
+++ b/dpid/main.c
@@ -15,11 +15,11 @@
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <errno.h>    /* for ckd_write */
-#include <unistd.h>   /* for ckd_write */
-#include <stdlib.h>   /* for exit */
-#include <assert.h>   /* for assert */
-#include <sys/stat.h> /* for umask */
+#include <errno.h>       /* for ckd_write */
+#include <unistd.h>      /* for ckd_write */
+#include <stdlib.h>      /* for exit */
+#include <assert.h>      /* for assert */
+#include <sys/stat.h>    /* for umask */
 
 #include "dpid_common.h"
 #include "dpid.h"
@@ -45,7 +45,7 @@ static int start_filter_plugin(struct dp dpi_attr)
 
    csz = (socklen_t) sizeof(clnt_addr);
 
-   newsock = accept(dpi_attr.socket, (struct sockaddr *) &clnt_addr, &csz);
+   newsock = accept(dpi_attr.sock_fd, (struct sockaddr *) &clnt_addr, &csz);
    if (newsock == -1)
       ERRMSG("start_plugin", "accept", errno);
 
@@ -90,12 +90,12 @@ static int start_filter_plugin(struct dp dpi_attr)
 
 static void start_server_plugin(struct dp dpi_attr)
 {
-   if (dup2(dpi_attr.socket, STDIN_FILENO) == -1) {
+   if (dup2(dpi_attr.sock_fd, STDIN_FILENO) == -1) {
       ERRMSG("start_plugin", "dup2", errno);
       MSG_ERR("ERROR in child proc for %s\n", dpi_attr.path);
       exit(1);
    }
-   if (a_Misc_close_fd(dpi_attr.socket) == -1) {
+   if (a_Misc_close_fd(dpi_attr.sock_fd) == -1) {
       ERRMSG("start_plugin", "close", errno);
       MSG_ERR("ERROR in child proc for %s\n", dpi_attr.path);
       exit(1);
@@ -220,7 +220,6 @@ static int get_open_max(void)
 int main(void)
 {
    int i, n = 0, open_max;
-   char *dirname = NULL, *sockdir = NULL;
    int dpid_idle_timeout = 60 * 60; /* default, in seconds */
    struct timeval select_timeout;
    sigset_t mask_none;
@@ -250,6 +249,7 @@ int main(void)
    /* Get list of available dpis */
    numdpis = register_all(&dpi_attr_list);
 
+#if 0
    /* Get name of socket directory */
    dirname = a_Dpi_sockdir_file();
    if ((sockdir = init_sockdir(dirname)) == NULL) {
@@ -257,14 +257,16 @@ int main(void)
       MSG_ERR("Failed to create socket directory\n");
       exit(1);
    }
+#endif
 
    /* Init and get services list */
    fill_services_list(dpi_attr_list, numdpis, &services_list);
 
    /* Remove any sockets that may have been leftover from a crash */
-   cleanup(sockdir);
+   //cleanup();
+
    /* Initialise sockets */
-   if ((numsocks = init_srs_socket(sockdir)) == -1) {
+   if ((numsocks = init_ids_srs_socket()) == -1) {
       switch (dpi_errno) {
       case dpid_srs_addrinuse:
          MSG_ERR("dpid refuses to start, possibly because:\n");
@@ -272,11 +274,12 @@ int main(void)
          MSG_ERR("\t2) A previous dpid didn't clean up on exit.\n");
          exit(1);
       default:
-         ERRMSG("main", "init_srs_sockets failed", 0);
+         //ERRMSG("main", "init_srs_socket failed", 0);
+         ERRMSG("main", "init_ids_srs_socket failed", 0);
          exit(1);
       }
    }
-   numsocks = init_all_dpi_sockets(dpi_attr_list, sockdir);
+   numsocks = init_all_dpi_sockets(dpi_attr_list);
    //est_terminator(); /* Do we still want to clean up on an abnormal exit? */
    est_dpi_sigchld();
 
@@ -308,7 +311,7 @@ int main(void)
                continue;
 
             stop_active_dpis(dpi_attr_list, numdpis);
-            cleanup(sockdir);
+            //cleanup();
             exit(0);
          }
       } while (n == -1 && errno == EINTR);
@@ -318,42 +321,42 @@ int main(void)
          exit(1);
       }
       /* If the service req socket is selected then service the req. */
-      if (FD_ISSET(srs, &selected_set)) {
-         int sock;
-         socklen_t csz;
-         struct sockaddr_un clnt_addr;
+      if (FD_ISSET(srs_fd, &selected_set)) {
+         int sock_fd;
+         socklen_t sin_sz;
+         struct sockaddr_in sin;
          char *req = NULL;
 
          --n;
          assert(n >= 0);
-         csz = (socklen_t) sizeof(clnt_addr);
-         sock = accept(srs, (struct sockaddr *) &clnt_addr, &csz);
-         if (sock == -1) {
+         sin_sz = (socklen_t) sizeof(sin);
+         sock_fd = accept(srs_fd, (struct sockaddr *)&sin, &sin_sz);
+         if (sock_fd == -1) {
             ERRMSG("main", "accept", errno);
             MSG_ERR("accept on srs socket failed\n");
             MSG_ERR("service pending connections, and continue\n");
          } else {
             int command;
 
-            req = get_request(sock);
-            command = get_command(sock, req);
+            req = get_request(sock_fd);
+            command = get_command(sock_fd, req);
             switch (command) {
             case BYE_CMD:
                stop_active_dpis(dpi_attr_list, numdpis);
-               cleanup(sockdir);
+               //cleanup();
                exit(0);
                break;
             case CHECK_SERVER_CMD:
-               send_sockpath(sock, req, dpi_attr_list);
+               send_sockport(sock_fd, req, dpi_attr_list);
                break;
             case REGISTER_ALL_CMD:
-               register_all_cmd(sockdir);
+               register_all_cmd();
                break;
             case UNKNOWN_CMD:
                {
                char *d_cmd = a_Dpip_build_cmd("cmd=%s msg=%s",
                                               "DpiError", "Unknown command");
-               (void) CKD_WRITE(sock, d_cmd);
+               (void) CKD_WRITE(sock_fd, d_cmd);
                dFree(d_cmd);
                ERRMSG("main", "Unknown command", 0);
                MSG_ERR(" for request: %s\n", req);
@@ -365,14 +368,14 @@ int main(void)
             }
             if (req)
                free(req);
-            a_Misc_close_fd(sock);
+            a_Misc_close_fd(sock_fd);
          }
       }
 
       /* While there's a request on one of the plugin sockets
        * find the matching plugin and start it. */
       for (i = 0; n > 0 && i < numdpis; i++) {
-         if (FD_ISSET(dpi_attr_list[i].socket, &selected_set)) {
+         if (FD_ISSET(dpi_attr_list[i].sock_fd, &selected_set)) {
             --n;
             assert(n >= 0);
 
@@ -386,11 +389,12 @@ int main(void)
                 * on its socket */
                numsocks--;
                assert(numsocks >= 0);
-               FD_CLR(dpi_attr_list[i].socket, &sock_set);
+               FD_CLR(dpi_attr_list[i].sock_fd, &sock_set);
                if ((dpi_attr_list[i].pid = fork()) == -1) {
                   ERRMSG("main", "fork", errno);
                   /* exit(1); */
                } else if (dpi_attr_list[i].pid == 0) {
+                  /* child */
                   (void) sigprocmask(SIG_SETMASK, &mask_none, NULL);
                   start_server_plugin(dpi_attr_list[i]);
                }