Add support for plugins (and specifically GPRS encryption plugins)
diff --git a/src/Makefile.am b/src/Makefile.am
index dc2309a..a7d450b 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -12,7 +12,13 @@
libosmocore_la_SOURCES = timer.c select.c signal.c msgb.c rxlev_stat.c \
tlv_parser.c bitvec.c comp128.c gsm_utils.c statistics.c \
write_queue.c utils.c rsl.c gsm48.c gsm48_ie.c \
- logging.c gsm0808.c rate_ctr.c gsmtap_util.c
+ logging.c gsm0808.c rate_ctr.c gsmtap_util.c \
+ gprs_cipher_core.c
+
+if ENABLE_PLUGIN
+libosmocore_la_SOURCES += plugin.c
+libosmocore_la_LDFLAGS = -ldl
+endif
if ENABLE_TALLOC
libosmocore_la_SOURCES += talloc.c
diff --git a/src/gprs_cipher_core.c b/src/gprs_cipher_core.c
new file mode 100644
index 0000000..a72dda8
--- /dev/null
+++ b/src/gprs_cipher_core.c
@@ -0,0 +1,85 @@
+/* GPRS LLC cipher core infrastructure */
+
+/* (C) 2010 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <errno.h>
+#include <stdint.h>
+
+#include <osmocore/utils.h>
+#include <osmocore/linuxlist.h>
+#include <osmocore/plugin.h>
+
+#include <osmocom/crypt/gprs_cipher.h>
+
+static LLIST_HEAD(gprs_ciphers);
+
+static struct gprs_cipher_impl *selected_ciphers[_GPRS_ALGO_NUM];
+
+/* register a cipher with the core */
+int gprs_cipher_register(struct gprs_cipher_impl *ciph)
+{
+ if (ciph->algo > ARRAY_SIZE(selected_ciphers))
+ return -ERANGE;
+
+ llist_add_tail(&ciph->list, &gprs_ciphers);
+
+ /* check if we want to select this implementation over others */
+ if (!selected_ciphers[ciph->algo] ||
+ (selected_ciphers[ciph->algo]->priority > ciph->priority))
+ selected_ciphers[ciph->algo] = ciph;
+
+ return 0;
+}
+
+/* load all available GPRS cipher plugins */
+int gprs_cipher_load(const char *path)
+{
+ /* load all plugins available from path */
+ return plugin_load_all(path);
+}
+
+/* function to be called by core code */
+int gprs_cipher_run(uint8_t *out, uint16_t len, enum gprs_ciph_algo algo,
+ uint64_t kc, uint32_t iv, enum gprs_cipher_direction dir)
+{
+ if (algo > ARRAY_SIZE(selected_ciphers))
+ return -ERANGE;
+
+ if (!selected_ciphers[algo])
+ return -EINVAL;
+
+ if (len > GSM0464_CIPH_MAX_BLOCK)
+ return -ERANGE;
+
+ /* run the actual cipher from the plugin */
+ return selected_ciphers[algo]->run(out, len, kc, iv, dir);
+}
+
+int gprs_cipher_supported(enum gprs_ciph_algo algo)
+{
+ if (algo > ARRAY_SIZE(selected_ciphers))
+ return -ERANGE;
+
+ if (selected_ciphers[algo])
+ return 1;
+
+ return 0;
+}
diff --git a/src/plugin.c b/src/plugin.c
new file mode 100644
index 0000000..e953508
--- /dev/null
+++ b/src/plugin.c
@@ -0,0 +1,62 @@
+/* plugin infrastructure */
+
+/* (C) 2010 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include "../config.h"
+
+#if HAVE_DLFCN_H
+
+#include <sys/types.h>
+#include <dirent.h>
+#include <dlfcn.h>
+#include <stdio.h>
+#include <errno.h>
+
+#include <osmocore/plugin.h>
+
+int plugin_load_all(const char *directory)
+{
+ unsigned int num = 0;
+ char fname[PATH_MAX];
+ DIR *dir;
+ struct dirent *entry;
+
+ dir = opendir(directory);
+ if (!dir)
+ return -errno;
+
+ while ((entry = readdir(dir))) {
+ snprintf(fname, sizeof(fname), "%s/%s", directory,
+ entry->d_name);
+ if (dlopen(fname, RTLD_NOW))
+ num++;
+ }
+
+ closedir(dir);
+
+ return num;
+}
+#else
+int plugin_load_all(const char *directory)
+{
+ return 0;
+}
+#endif /* HAVE_DLFCN_H */