---
lib/Makefile.am | 10 +++-
lib/plugin.c | 177 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
lib/plugin.h | 117 +++++++++++++++++++++++++++++++++++++
3 files changed, 301 insertions(+), 3 deletions(-)
create mode 100644 lib/plugin.c
create mode 100644 lib/plugin.h
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 1e9b05f..1caa7d9 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -15,13 +15,15 @@ libzebra_la_SOURCES = \
zclient.c sockopt.c smux.c agentx.c snmp.c md5.c if_rmap.c keychain.c
privs.c \
sigevent.c pqueue.c jhash.c workqueue.c vrf.c \
memory.c \
- memory_vty.c
+ memory_vty.c \
+ plugin.c \
+ # end
BUILT_SOURCES = route_types.h gitversion.h
libzebra_la_DEPENDENCIES = @LIB_REGEX@
-libzebra_la_LIBADD = @LIB_REGEX@ @LIBCAP@
+libzebra_la_LIBADD = -ldl @LIB_REGEX@ @LIBCAP@
pkginclude_HEADERS = \
buffer.h checksum.h command.h filter.h getopt.h hash.h \
@@ -31,7 +33,9 @@ pkginclude_HEADERS = \
plist.h zclient.h sockopt.h smux.h md5.h if_rmap.h keychain.h \
privs.h sigevent.h pqueue.h jhash.h zassert.h \
workqueue.h route_types.h libospf.h vrf.h fifo.h \
- memory_vty.h
+ memory_vty.h \
+ plugin.h \
+ # end
noinst_HEADERS = \
plist_int.h
diff --git a/lib/plugin.c b/lib/plugin.c
new file mode 100644
index 0000000..81635a7
--- /dev/null
+++ b/lib/plugin.c
@@ -0,0 +1,177 @@
+/*
+ * Copyright (c) 2015-16 David Lamparter, for NetDEF, Inc.
+ *
+ * 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 "config.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <limits.h>
+#include <dlfcn.h>
+
+#include "plugin.h"
+#include "memory.h"
+#include "version.h"
+
+DEFINE_MTYPE_STATIC(LIB, PLUGIN_LOADNAME, "Plugin loading name")
+DEFINE_MTYPE_STATIC(LIB, PLUGIN_LOADARGS, "Plugin loading arguments")
+
+static struct qplug_info qplug_daemon_executable_info = {
+ .name = "libzebra",
+ .version = QUAGGA_VERSION,
+ .description = "libzebra (no plugin)",
+};
+union _qplug_runtime_u qplug_default = {
+ .r.info = &qplug_daemon_executable_info,
+ .r.finished_loading = 1,
+};
+
+#if defined(HAVE_SYS_WEAK_ALIAS_ATTRIBUTE)
+union _qplug_runtime_u _qplug_this_plugin
+ __attribute__((weak, alias("qplug_default")));
+#elif defined(HAVE_SYS_WEAK_ALIAS_PRAGMA)
+#pragma weak _qplug_this_plugin = qplug_default
+#else
+#error need weak symbol support
+#endif
+
+struct qplug_runtime *qplug_list = &_qplug_this_plugin.r;
+static struct qplug_runtime **qplug_last = &_qplug_this_plugin.r.next;
+
+#define PLUGIN_PATH "/usr/lib/quagga/plugins"
+
+struct qplug_runtime *qplug_load(const char *spec,
+ char *err, size_t err_len)
+{
+ void *handle = NULL, *handle2;
+ char name[PATH_MAX], fullpath[PATH_MAX], *args;
+ struct qplug_runtime *rtinfo;
+ const struct qplug_info *info;
+
+ snprintf(name, sizeof(name), "%s", spec);
+ args = strchr(name, ':');
+ if (args)
+ *args++ = '\0';
+
+ if (!strchr(name, '/')) {
+ snprintf(fullpath, sizeof(fullpath), "%s/%s.so",
+ PLUGIN_PATH, name);
+ handle = dlopen(fullpath, RTLD_LAZY | RTLD_GLOBAL);
+ }
+ if (!handle) {
+ snprintf(fullpath, sizeof(fullpath), "%s", name);
+ handle = dlopen(fullpath, RTLD_LAZY | RTLD_GLOBAL);
+ }
+ if (!handle) {
+ if (err)
+ snprintf(err, err_len,
+ "loading plugin \"%s\" failed: %s",
+ name, dlerror());
+ return NULL;
+ }
+
+ rtinfo = dlsym(handle, "_qplug_this_plugin");
+ if (!rtinfo) {
+ dlclose(handle);
+ if (err)
+ snprintf(err, err_len,
+ "\"%s\" is not a Quagga plugin: %s",
+ name, dlerror());
+ return NULL;
+ }
+ rtinfo->load_name = XSTRDUP(MTYPE_PLUGIN_LOADNAME, name);
+ if (args)
+ rtinfo->load_args = XSTRDUP(MTYPE_PLUGIN_LOADARGS, args);
+ info = rtinfo->info;
+
+ if (rtinfo->finished_loading) {
+ dlclose(handle);
+ if (err)
+ snprintf(err, err_len,
+ "plugin \"%s\" already loaded",
+ name);
+ goto out_fail;
+ }
+
+#if 0
+ /* not worth the effort - incompatible plugins will fail to load
+ * with undefined references anyway */
+ do {
+ char daemon_delim[64];
+ snprintf(daemon_delim, sizeof(daemon_delim), ";%s;",
+ qplug_daemon_name);
+
+ if (!info->compat_list)
+ break;
+ if (strstr(info->compat_list, daemon_delim))
+ break;
+ if (strstr(info->compat_list, ";all;"))
+ break;
+
+ dlclose(handle);
+ if (err)
+ snprintf(err, err_len,
+ "plugin \"%s\" not compatible with"
+ "this Quagga daemon", name);
+ goto out_fail;
+ } while (0);
+#endif
+
+ /* force symbol resolution now, so we don't explode at runtime.
+ * this is not on first load to make more specific errors possible */
+ handle2 = dlopen(fullpath, RTLD_NOW | RTLD_GLOBAL);
+ if (!handle2) {
+ if (err)
+ snprintf(err, err_len,
+ "plugin \"%s\" symbol resolution "
+ "failed: %s", name, dlerror());
+ dlclose(handle);
+ goto out_fail;
+ }
+ dlclose(handle);
+ rtinfo->dl_handle = handle2;
+
+ if (info->init && info->init()) {
+ dlclose(handle2);
+ if (err)
+ snprintf(err, err_len,
+ "plugin \"%s\" initialisation failed",
+ name);
+ goto out_fail;
+ }
+
+ rtinfo->finished_loading = 1;
+
+ *qplug_last = rtinfo;
+ qplug_last = &rtinfo->next;
+ return rtinfo;
+
+out_fail:
+ if (rtinfo->load_args)
+ XFREE(MTYPE_PLUGIN_LOADARGS, rtinfo->load_args);
+ XFREE(MTYPE_PLUGIN_LOADNAME, rtinfo->load_name);
+ return NULL;
+}
+
+void qplug_unload(struct qplug_runtime *plugin)
+{
+}
diff --git a/lib/plugin.h b/lib/plugin.h
new file mode 100644
index 0000000..4ddf8df
--- /dev/null
+++ b/lib/plugin.h
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2015-16 David Lamparter, for NetDEF, Inc.
+ *
+ * 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.
+ */
+
+#ifndef _QUAGGA_PLUGIN_H
+#define _QUAGGA_PLUGIN_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#if !defined(__GNUC__)
+# error plugin code needs GCC visibility extensions
+#elif __GNUC__ < 4
+# error plugin code needs GCC visibility extensions
+#else
+# define DSO_PUBLIC __attribute__ ((visibility ("default")))
+# define DSO_SELF __attribute__ ((visibility ("protected")))
+# define DSO_LOCAL __attribute__ ((visibility ("hidden")))
+#endif
+
+struct qplug_runtime;
+
+struct qplug_info {
+ /* single-line few-word title */
+ const char *name;
+ /* human-readable version number, should not contain spaces */
+ const char *version;
+ /* one-paragraph description */
+ const char *description;
+
+ int (*init)(void);
+
+#if 0
+ /* list of daemons with which this plugin can be used.
+ * semicolon separated: ";daemon1;daemon2;daemon3;"
+ * (note semicolon at start!)
+ * NULL or special value "all" means no restrictions.
+ *
+ * NB: in most cases, loading a daemon-specific module will fail
+ * anyway because there will be unresolved symbols
+ * (if not, loader code will unload the module without calling init)
+ */
+ const char *compat_list;
+
+ /* for version checks when depending on other plugins; not used or
+ * displayed anywhere in main Quagga
+ *
+ * failing with unresolved symbols when a prerequisite plugin is
+ * missing is always an option too */
+ uint8_t v_major, v_minor, v_revision, v_patch;
+#endif
+};
+
+/* primary entry point structure to be present in loadable plugin under
+ * "_qplug_this_plugin" dlsym() name
+ *
+ * note space for future extensions is reserved below, so other modules
+ * (e.g. memory management, hooks) can add fields
+ *
+ * const members/info are in qplug_info.
+ */
+struct qplug_runtime {
+ struct qplug_runtime *next;
+
+ const struct qplug_info *info;
+ void *dl_handle;
+ bool finished_loading;
+
+ char *load_name;
+ char *load_args;
+};
+
+/* space-reserving foo */
+struct _qplug_runtime_size {
+ struct qplug_runtime r;
+ /* this will barf if qplug_runtime exceeds 1024 bytes ... */
+ uint8_t space[1024 - sizeof(struct qplug_runtime)];
+};
+union _qplug_runtime_u {
+ struct qplug_runtime r;
+ struct _qplug_runtime_size s;
+};
+
+extern DSO_SELF union _qplug_runtime_u _qplug_this_plugin;
+#define THIS_PLUGIN (&_qplug_this_plugin.r)
+
+#define QUAGGA_PLUGIN_SETUP(...) \
+ static const struct qplug_info _qplug_info = { __VA_ARGS__ }; \
+ DSO_SELF union _qplug_runtime_u _qplug_this_plugin = { \
+ .r.info = &_qplug_info, \
+ };
+
+extern struct qplug_runtime *qplug_list;
+
+extern struct qplug_runtime *qplug_load(const char *spec,
+ char *err, size_t err_len);
+extern void qplug_unload(struct qplug_runtime *plugin);
+
+#endif /* _QUAGGA_PLUGIN_H */
--
2.7.3
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