1 files changed, 111 insertions, 0 deletions
diff --git a/src/nlapi.c b/src/nlapi.c
new file mode 100644
index 0000000..1f6e690
--- /dev/null
+++ b/src/nlapi.c
@@ -0,0 +1,111 @@
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <assert.h>
+#include <stdlib.h>
+
+#include <libdaemon/dlog.h>
+
+#include "nlapi.h"
+
+int nlapi_fd = -1;
+
+struct callback_info {
+    nlapi_callback_t callback;
+    void *userdata;
+    struct callback_info * next;
+};
+
+struct callback_info *callbacks = NULL;
+
+int nlapi_open(uint32_t groups) {
+    struct sockaddr_nl addr;
+
+    if ((nlapi_fd = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE)) < 0) {
+        fprintf(stderr, "socket(PF_NETLINK): %s\n", strerror(errno));
+        return -1;
+    }
+
+    memset(&addr, 0, sizeof(addr));
+    addr.nl_family = AF_NETLINK;
+    addr.nl_groups = groups;
+    addr.nl_pid = getpid();
+
+    if (bind(nlapi_fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
+        close(nlapi_fd);
+        fprintf(stderr, "bind(): %s\n", strerror(errno));
+        return -1;
+    }
+
+    return 0;
+}
+
+int nlapi_work(int block) {
+
+    assert(nlapi_fd >= 0);
+    
+    for (;;) {
+        int bytes;
+        char replybuf[1024];
+        struct nlmsghdr *p = (struct nlmsghdr *) replybuf;
+        
+        if ((bytes = recv(nlapi_fd, &replybuf, sizeof(replybuf), block ? 0 : MSG_DONTWAIT)) < 0) {
+
+            if (errno == EAGAIN || errno == EINTR)
+                return 0;
+            
+            daemon_log(LOG_ERR, "NLAPI: recv(): %s\n", strerror(errno));
+            return -1;
+        }
+
+        for (; bytes > 0; p = NLMSG_NEXT(p, bytes)) {
+            struct callback_info *c;
+            
+            if (!NLMSG_OK(p, bytes) || bytes < sizeof(struct nlmsghdr) || bytes < p->nlmsg_len) {
+                daemon_log(LOG_ERR, "NLAPI: Packet too small or truncated!\n");
+                return -1;
+            }
+            
+            for (c = callbacks; c; c = c->next)
+                if (c->callback(p, c->userdata) < 0)
+                    return -1;
+        }
+
+        if (block)
+            break;
+    }
+
+    return 0;
+}
+
+void nlapi_close(void) {
+    if (nlapi_fd >= 0)
+        close(nlapi_fd);
+    nlapi_fd = -1;
+
+
+    while (callbacks) {
+        struct callback_info *c = callbacks;
+        callbacks = callbacks->next;
+        free(c);
+    }
+}
+
+int nlapi_register(int (*callback) (struct nlmsghdr *n, void *u), void *u) {
+    struct callback_info *c;
+
+    assert(callback);
+    
+    if (!(c = malloc(sizeof(struct callback_info)))) {
+        daemon_log(LOG_ERR, "NLAPI: Not enough memory.\n");
+        return -1;
+    }
+
+    c->callback = callback;
+    c->userdata = u;
+
+    c->next = callbacks;
+    callbacks = c;
+    return 0;
+}