src: major API redesign

This patch reworks the initial API. Now it provides functions to:

- allocate/release accounting objects.
- set/unset/get attributes of accounting objects.
- build one netlink message from one accounting object.
- parse one netlink message to one accounting object.
- print one accounting object into a buffer.

Binary layout of nfacct objects are opaque. This is good for
extensibility without breaking backward compatibility.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

3 files changed, 114 insertions, 9 deletions

diff --git a/examples/nfacct-add.c b/examples/nfacct-add.c
index 64f94d1..40e0e31 100644
--- a/examples/nfacct-add.c
+++ b/examples/nfacct-add.c
@@ -10,18 +10,28 @@ int main(int argc, char *argv[])
 	char buf[MNL_SOCKET_BUFFER_SIZE];
 	struct nlmsghdr *nlh;
 	uint32_t portid, seq;
-	struct nfacct nfacct = {};
+	struct nfacct *nfacct;
 	int ret;
 
 	if (argc != 2) {
 		fprintf(stderr, "Usage: %s [name]\n", argv[0]);
 		exit(EXIT_FAILURE);
 	}
-	strncpy(nfacct.name, argv[1], NFACCT_NAME_MAX);
-	nfacct.name[NFACCT_NAME_MAX-1] = '\0';
 
-	nlh = nfacct_add(buf, &nfacct);
-	seq = nlh->nlmsg_seq = time(NULL);
+	nfacct = nfacct_alloc();
+	if (nfacct == NULL) {
+		perror("OOM");
+		exit(EXIT_FAILURE);
+	}
+
+	nfacct_attr_set(nfacct, NFACCT_ATTR_NAME, argv[1]);
+
+	seq = time(NULL);
+	nlh = nfacct_nlmsg_build_hdr(buf, NFNL_MSG_ACCT_NEW,
+				     NLM_F_CREATE | NLM_F_ACK, seq);
+	nfacct_nlmsg_build_payload(nlh, nfacct);
+
+	nfacct_free(nfacct);
 
 	nl = mnl_socket_open(NETLINK_NETFILTER);
 	if (nl == NULL) {
@@ -42,7 +52,7 @@ int main(int argc, char *argv[])
 
 	ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
 	while (ret > 0) {
-		ret = mnl_cb_run(buf, ret, seq, portid, nfacct_list_cb, NULL);
+		ret = mnl_cb_run(buf, ret, seq, portid, NULL, NULL);
 		if (ret <= 0)
 			break;
 		ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
diff --git a/examples/nfacct-del.c b/examples/nfacct-del.c
new file mode 100644
index 0000000..7a1190c
--- /dev/null
+++ b/examples/nfacct-del.c
@@ -0,0 +1,67 @@
+#include <stdlib.h>
+#include <time.h>
+#include <string.h>
+#include <libmnl/libmnl.h>
+#include <libnetfilter_acct/libnetfilter_acct.h>
+
+int main(int argc, char *argv[])
+{
+	struct mnl_socket *nl;
+	char buf[MNL_SOCKET_BUFFER_SIZE];
+	struct nlmsghdr *nlh;
+	uint32_t portid, seq;
+	struct nfacct *nfacct;
+	int ret;
+
+	if (argc != 2) {
+		fprintf(stderr, "Usage: %s [name]\n", argv[0]);
+		exit(EXIT_FAILURE);
+	}
+
+	nfacct = nfacct_alloc();
+	if (nfacct == NULL) {
+		perror("OOM");
+		exit(EXIT_FAILURE);
+	}
+
+	nfacct_attr_set(nfacct, NFACCT_ATTR_NAME, argv[1]);
+
+	seq = time(NULL);
+	nlh = nfacct_nlmsg_build_hdr(buf, NFNL_MSG_ACCT_DEL,
+				     NLM_F_ACK, seq);
+	nfacct_nlmsg_build_payload(nlh, nfacct);
+
+	nfacct_free(nfacct);
+
+	nl = mnl_socket_open(NETLINK_NETFILTER);
+	if (nl == NULL) {
+		perror("mnl_socket_open");
+		exit(EXIT_FAILURE);
+	}
+
+	if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) {
+		perror("mnl_socket_bind");
+		exit(EXIT_FAILURE);
+	}
+	portid = mnl_socket_get_portid(nl);
+
+	if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
+		perror("mnl_socket_send");
+		exit(EXIT_FAILURE);
+	}
+
+	ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
+	while (ret > 0) {
+		ret = mnl_cb_run(buf, ret, seq, portid, NULL, NULL);
+		if (ret <= 0)
+			break;
+		ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
+	}
+	if (ret == -1) {
+		perror("error");
+		exit(EXIT_FAILURE);
+	}
+	mnl_socket_close(nl);
+
+	return EXIT_SUCCESS;
+}
diff --git a/examples/nfacct-get.c b/examples/nfacct-get.c
index 7b22352..fffa3ec 100644
--- a/examples/nfacct-get.c
+++ b/examples/nfacct-get.c
@@ -4,6 +4,31 @@
 #include <libmnl/libmnl.h>
 #include <libnetfilter_acct/libnetfilter_acct.h>
 
+static int nfacct_cb(const struct nlmsghdr *nlh, void *data)
+{
+	struct nfacct *nfacct;
+	char buf[4096];
+
+	nfacct = nfacct_alloc();
+	if (nfacct == NULL) {
+		perror("OOM");
+		goto err;
+	}
+
+	if (nfacct_nlmsg_parse_payload(nlh, nfacct) < 0) {
+		perror("nfacct_parse_nl_msg");
+		goto err_free;
+	}
+
+	nfacct_snprintf(buf, sizeof(buf), nfacct, NFACCT_SNPRINTF_F_FULL);
+	printf("%s\n", buf);
+
+err_free:
+	nfacct_free(nfacct);
+err:
+	return MNL_CB_OK;
+}
+
 int main(int argc, char *argv[])
 {
 	struct mnl_socket *nl;
@@ -21,8 +46,11 @@ int main(int argc, char *argv[])
 	if (argc == 2 && strncmp(argv[1], "-z", strlen("-z")) == 0)
 		zeroctr = true;
 
-	nlh = nfacct_list(buf, zeroctr);
-	seq = nlh->nlmsg_seq = time(NULL);
+	seq = time(NULL);
+	nlh = nfacct_nlmsg_build_hdr(buf, zeroctr ?
+					NFNL_MSG_ACCT_GET_CTRZERO :
+					NFNL_MSG_ACCT_GET,
+				     NLM_F_DUMP, seq);
 
 	nl = mnl_socket_open(NETLINK_NETFILTER);
 	if (nl == NULL) {
@@ -43,7 +71,7 @@ int main(int argc, char *argv[])
 
 	ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
 	while (ret > 0) {
-		ret = mnl_cb_run(buf, ret, seq, portid, nfacct_list_cb, &full);
+		ret = mnl_cb_run(buf, ret, seq, portid, nfacct_cb, &full);
 		if (ret <= 0)
 			break;
 		ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));