[Commit-gnuradio] r9502 - usrp2/trunk/host/lib

[eb]

Author: eb
Date: 2008-09-05 03:10:47 -0600 (Fri, 05 Sep 2008)
New Revision: 9502

Added:
   usrp2/trunk/host/lib/open_usrp2_socket.cc
   usrp2/trunk/host/lib/open_usrp2_socket.h
Modified:
   usrp2/trunk/host/lib/Makefile.am
   usrp2/trunk/host/lib/ethernet.cc
   usrp2/trunk/host/lib/usrp2_socket_opener.cc
Log:
usrp2 can now be opened without running as root

Modified: usrp2/trunk/host/lib/Makefile.am
===================================================================
--- usrp2/trunk/host/lib/Makefile.am    2008-09-05 08:38:37 UTC (rev 9501)
+++ usrp2/trunk/host/lib/Makefile.am    2008-09-05 09:10:47 UTC (rev 9502)
@@ -34,6 +34,7 @@
        eth_buffer.cc \
        ethernet.cc \
        find.cc \
+       open_usrp2_socket.cc \
        pktfilter.cc \
        ring.cc \
        rx_nop_handler.cc \

Modified: usrp2/trunk/host/lib/ethernet.cc
===================================================================
--- usrp2/trunk/host/lib/ethernet.cc    2008-09-05 08:38:37 UTC (rev 9501)
+++ usrp2/trunk/host/lib/ethernet.cc    2008-09-05 09:10:47 UTC (rev 9502)
@@ -22,6 +22,7 @@
 
 #include "ethernet.h"
 #include "pktfilter.h"
+#include <open_usrp2_socket.h>
 
 #include <iostream>
 #include <unistd.h>
@@ -44,10 +45,15 @@
   static int
   open_packet_socket (std::string ifname, int protocol)
   {
+#if 0    
     if (protocol == 0)
       protocol = htons(ETH_P_ALL);
     
     int fd = socket (PF_PACKET, SOCK_RAW, protocol);
+#else
+    int fd = usrp2::open_usrp2_socket();
+#endif
+
     if (fd == -1){
       fprintf (stderr, "%s: socket: %s\n", ifname.c_str(), strerror (errno));
       return -1;

Added: usrp2/trunk/host/lib/open_usrp2_socket.cc
===================================================================
--- usrp2/trunk/host/lib/open_usrp2_socket.cc                           (rev 0)
+++ usrp2/trunk/host/lib/open_usrp2_socket.cc   2008-09-05 09:10:47 UTC (rev 
9502)
@@ -0,0 +1,130 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2008 Free Software Foundation, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <open_usrp2_socket.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string>
+
+static const char *helper = "usrp2_socket_opener";
+
+static ssize_t
+read_fd(int fd, void *ptr, size_t nbytes, int *recvfd)
+{
+  struct msghdr msg;
+  struct iovec iov[1];
+  ssize_t n;
+
+#ifdef HAVE_STRUCT_MSGHDR_MSG_CONTROL
+  union {
+    struct cmsghdr cm;
+    char     control[CMSG_SPACE(sizeof (int))];
+  } control_un;
+  struct cmsghdr  *cmptr;
+
+  msg.msg_control  = control_un.control;
+  msg.msg_controllen = sizeof(control_un.control);
+#else
+  int     newfd;
+
+  msg.msg_accrights = (char *) &newfd;
+  msg.msg_accrightslen = sizeof(int);
+#endif
+
+  msg.msg_name = NULL;
+  msg.msg_namelen = 0;
+
+  iov[0].iov_base = ptr;
+  iov[0].iov_len = nbytes;
+  msg.msg_iov = iov;
+  msg.msg_iovlen = 1;
+
+  if ((n = recvmsg(fd, &msg, 0)) <= 0)
+    return n;
+
+#ifdef  HAVE_STRUCT_MSGHDR_MSG_CONTROL
+  if ((cmptr = CMSG_FIRSTHDR(&msg)) != NULL
+      && cmptr->cmsg_len == CMSG_LEN(sizeof(int))){
+    if (cmptr->cmsg_level != SOL_SOCKET){
+      fprintf(stderr, "read_fd: control level != SOL_SOCKET\n");
+      return -1;
+    }
+    if (cmptr->cmsg_type != SCM_RIGHTS){
+      fprintf(stderr, "read_fd: control type != SCM_RIGHTS\n");
+      return -1;
+    }
+    *recvfd = *((int *) CMSG_DATA(cmptr));
+  } else
+    *recvfd = -1;           /* descriptor was not passed */
+#else
+  if (msg.msg_accrightslen == sizeof(int))
+    *recvfd = newfd;
+  else
+    *recvfd = -1;       /* descriptor was not passed */
+#endif
+
+  return n;
+}
+
+int
+usrp2::open_usrp2_socket()
+{
+  int     fd = -1, sockfd[2], status;
+  pid_t   childpid;
+  char    c, argsockfd[10];
+
+  if (socketpair(AF_LOCAL, SOCK_STREAM, 0, sockfd) != 0){
+    perror("socketpair");
+    return -1;
+  }
+
+  if ((childpid = fork()) == 0) { /* child process */
+    close(sockfd[0]);
+    snprintf(argsockfd, sizeof(argsockfd), "%d", sockfd[1]);
+    execlp(helper, helper, argsockfd, (char *) NULL);
+    std::string msg("execlp: couldn't exec " + std::string(helper));
+    perror(msg.c_str());
+    close(sockfd[0]);
+    close(sockfd[1]);
+    return -1;
+  }
+
+  /* parent process - wait for the child to terminate */
+  close(sockfd[1]);           /* close the end we don't use */
+
+  waitpid(childpid, &status, 0);
+  if (!WIFEXITED(status)){
+    fprintf(stderr, "child did not terminate\n");
+    return -1;
+  }
+  if ((status = WEXITSTATUS(status)) == 0)
+    read_fd(sockfd[0], &c, 1, &fd);
+  else {
+    errno = status;         /* bogus: set errno value from child's status */
+    fd = -1;
+  }
+
+  close(sockfd[0]);
+  return (fd);
+}


Property changes on: usrp2/trunk/host/lib/open_usrp2_socket.cc
___________________________________________________________________
Name: svn:eol-style
   + native

Added: usrp2/trunk/host/lib/open_usrp2_socket.h
===================================================================
--- usrp2/trunk/host/lib/open_usrp2_socket.h                            (rev 0)
+++ usrp2/trunk/host/lib/open_usrp2_socket.h    2008-09-05 09:10:47 UTC (rev 
9502)
@@ -0,0 +1,34 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2008 Free Software Foundation, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef INCLUDED_OPEN_USRP2_SOCKET_H
+#define INCLUDED_OPEN_USRP2_SOCKET_H
+
+namespace usrp2 {
+
+  /*!
+   * Return the result of executing:
+   *
+   *   int fd = socket(PF_PACKET, SOCK_RAW, htons(0xBEEF));
+   *
+   * Doing it in a way that we don't need to be running as root.
+   */
+  int open_usrp2_socket();
+};
+
+
+#endif /* INCLUDED_OPEN_USRP2_SOCKET_H */


Property changes on: usrp2/trunk/host/lib/open_usrp2_socket.h
___________________________________________________________________
Name: svn:eol-style
   + native

Modified: usrp2/trunk/host/lib/usrp2_socket_opener.cc
===================================================================
--- usrp2/trunk/host/lib/usrp2_socket_opener.cc 2008-09-05 08:38:37 UTC (rev 
9501)
+++ usrp2/trunk/host/lib/usrp2_socket_opener.cc 2008-09-05 09:10:47 UTC (rev 
9502)
@@ -78,15 +78,15 @@
 }
 
 bool
-reset_eids ()
+reset_eids()
 {
-  if (setgid (getgid ()) < 0){
-    perror ("setguid");
+  if (setgid(getgid()) < 0){
+    perror("setguid");
     return false;
   }
 
-  if (setuid (getuid ()) < 0){
-    perror ("setuid");
+  if (setuid(getuid()) < 0){
+    perror("setuid");
     return false;
   }
 
@@ -115,15 +115,15 @@
   // FIXME get client credentials from unix_domain_fd using SCM_CREDENTIALS
 
   // open the raw socket
-  int socket_fd = socket (PF_PACKET, SOCK_RAW, htons(0xBEEF));
+  int socket_fd = socket(PF_PACKET, SOCK_RAW, htons(0xBEEF));
   if (socket_fd == -1){
     perror("socket(PF_PACKET, SOCK_RAW, htons(0xBEEF))");
     // printf("errno = %d\n", errno);
     if (errno == EACCES || errno == ESPIPE){
-      fprintf (stderr, "usrp2_socket_opener must be setuid root to open the 
socket using SOCK_RAW.\n");
-      fprintf (stderr, "Running as root, please execute:  \n");
-      fprintf (stderr, "  # chown root usrp2_socket_opener\n");
-      fprintf (stderr, "  # chmod u+s usrp2_socket_opener\n");
+      fprintf(stderr, "usrp2_socket_opener must be setuid root to open the 
socket using SOCK_RAW.\n");
+      fprintf(stderr, "Running as root, please execute:  \n");
+      fprintf(stderr, "  # chown root usrp2_socket_opener\n");
+      fprintf(stderr, "  # chmod u+s usrp2_socket_opener\n");
     }
     exit(2);
   }