babeld: Initial import, for Babel routing protocol.

* Initial import of the Babel routing protocol, ported to Quagga.
* LICENCE: Update the original LICENCE file to include all known potentially
  applicable copyright claims.  Ask that any future contributors to babeld/
  grant MIT/X11 licence to their work.
* *.{c,h}: Add GPL headers, in according with the SFLC guidance on
  dealing with potentially mixed GPL/other licensed work, at:

  https://www.softwarefreedom.org/resources/2007/gpl-non-gpl-collaboration.html

1 files changed, 113 insertions, 0 deletions

diff --git a/babeld/kernel.c b/babeld/kernel.c
new file mode 100644
index 0000000000..4b5bd7b29a
--- /dev/null
+++ b/babeld/kernel.c
@@ -0,0 +1,113 @@
+/*  
+ *  This file is free software: you may copy, redistribute and/or modify it  
+ *  under the terms of the GNU General Public License as published by the  
+ *  Free Software Foundation, either version 2 of the License, or (at your  
+ *  option) any later version.  
+ *  
+ *  This file 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/>.  
+ *  
+ * This file incorporates work covered by the following copyright and  
+ * permission notice:  
+ *  
+
+Copyright 2007, 2008 by Grégoire Henry, Julien Cristau and Juliusz Chroboczek
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+#include <sys/time.h>
+#include <sys/param.h>
+#include <time.h>
+
+#include "babeld.h"
+
+#include "kernel_zebra.c"
+
+/* Like gettimeofday, but returns monotonic time.  If POSIX clocks are not
+   available, falls back to gettimeofday but enforces monotonicity. */
+int
+gettime(struct timeval *tv)
+{
+    int rc;
+    static time_t offset = 0, previous = 0;
+
+#if defined(_POSIX_TIMERS) && _POSIX_TIMERS > 0 && defined(CLOCK_MONOTONIC)
+    static int have_posix_clocks = -1;
+
+    if(UNLIKELY(have_posix_clocks < 0)) {
+        struct timespec ts;
+        rc = clock_gettime(CLOCK_MONOTONIC, &ts);
+        if(rc < 0) {
+            have_posix_clocks = 0;
+        } else {
+            have_posix_clocks = 1;
+        }
+    }
+
+    if(have_posix_clocks) {
+        struct timespec ts;
+        int rc;
+        rc = clock_gettime(CLOCK_MONOTONIC, &ts);
+        if(rc < 0)
+            return rc;
+        tv->tv_sec = ts.tv_sec;
+        tv->tv_usec = ts.tv_nsec / 1000;
+        return rc;
+    }
+#endif
+
+    rc = gettimeofday(tv, NULL);
+    if(rc < 0)
+        return rc;
+    tv->tv_sec += offset;
+    if(UNLIKELY(previous > tv->tv_sec)) {
+        offset += previous - tv->tv_sec;
+        tv->tv_sec = previous;
+    }
+    previous = tv->tv_sec;
+    return rc;
+}
+
+/* If /dev/urandom doesn't exist, this will fail with ENOENT, which the
+   caller will deal with gracefully. */
+
+int
+read_random_bytes(void *buf, size_t len)
+{
+    int fd;
+    int rc;
+
+    fd = open("/dev/urandom", O_RDONLY);
+    if(fd < 0) {
+        rc = -1;
+    } else {
+        rc = read(fd, buf, len);
+        if(rc < 0 || (unsigned) rc < len)
+            rc = -1;
+        close(fd);
+    }
+    return rc;
+}
+