packet: Add support for mclists

The implementation is rather straightforward. One thing to note
is that non-single membership of each type is not supported. It
can be done, but I'm unaware of any software doing so.

Note: the pb show routine should be tuned to support showing bytes.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

include/packet_diag.h

@@ -52,6 +52,7 @@ struct packet_diag_info {
 
 struct packet_diag_mclist {
 	__u32   pdmc_index;
+	__u32   pdmc_count;
 	__u16   pdmc_type;
 	__u16   pdmc_alen;
 	__u8    pdmc_addr[MAX_ADDR_LEN];

protobuf/packet-sock.proto

 import "fown.proto";
 import "sk-opts.proto";
 
+message packet_mclist {
+	required uint32	index	= 1;
+	required uint32	type	= 2;
+	required bytes	addr	= 3;
+}
+
 message packet_sock_entry {
 	required uint32			id		= 1;
 	required uint32			type		= 2;
@@ -19,4 +25,5 @@ message packet_sock_entry {
 	required bool		loss		= 13;
 	required uint32		timestamp	= 14;
 	required uint32		copy_thresh	= 15;
+	repeated packet_mclist	mclist		= 16;
 }

sk-packet.c

@@ -21,11 +21,20 @@ struct packet_sock_info {
 	struct file_desc d;
 };
 
+struct packet_mreq_max {
+	int             mr_ifindex;
+	unsigned short  mr_type;
+	unsigned short  mr_alen;
+	unsigned char   mr_address[MAX_ADDR_LEN];
+};
+
 struct packet_sock_desc {
 	struct socket_desc sd;
 	unsigned int type;
 	unsigned short proto;
 	struct packet_diag_info nli;
+	int mreq_n;
+	struct packet_diag_mclist *mreqs;
 };
 
 void show_packetsk(int fd, struct cr_options *o)
@@ -33,11 +42,71 @@ void show_packetsk(int fd, struct cr_options *o)
 	pb_show_plain(fd, PB_PACKETSK);
 }
 
+static int dump_mreqs(PacketSockEntry *psk, struct packet_sock_desc *sd)
+{
+	int i;
+
+	if (!sd->mreq_n)
+		return 0;
+
+	pr_debug("\tdumping %d mreqs\n", sd->mreq_n);
+	psk->mclist = xmalloc(sd->mreq_n * sizeof(psk->mclist[0]));
+	if (!psk->mclist)
+		return -1;
+
+	for (i = 0; i < sd->mreq_n; i++) {
+		struct packet_diag_mclist *m = &sd->mreqs[i];
+		PacketMclist *im;
+
+		if (m->pdmc_count != 1) {
+			pr_err("Multiple MC membership not supported (but can be)\n");
+			goto err;
+		}
+
+		pr_debug("\tmr%d: idx %d type %d\n", i,
+				m->pdmc_index, m->pdmc_type);
+
+		im = xmalloc(sizeof(*im));
+		if (!im)
+			goto err;
+
+		packet_mclist__init(im);
+		psk->mclist[i] = im;
+		psk->n_mclist++;
+
+		im->index = m->pdmc_index;
+		im->type = m->pdmc_type;
+
+		switch (m->pdmc_type) {
+			case PACKET_MR_MULTICAST:
+			case PACKET_MR_UNICAST:
+				im->addr.len = m->pdmc_alen;
+				im->addr.data = xmalloc(m->pdmc_alen);
+				if (!im->addr.data)
+					goto err;
+
+				memcpy(im->addr.data, m->pdmc_addr, m->pdmc_alen);
+				break;
+			case PACKET_MR_PROMISC:
+			case PACKET_MR_ALLMULTI:
+				break;
+			default:
+				pr_err("Unknown mc membership type %d\n", m->pdmc_type);
+				goto err;
+		}
+	}
+
+	return 0;
+err:
+	return -1;
+}
+
 static int dump_one_packet_fd(int lfd, u32 id, const struct fd_parms *p)
 {
 	PacketSockEntry psk = PACKET_SOCK_ENTRY__INIT;
 	SkOptsEntry skopts = SK_OPTS_ENTRY__INIT;
 	struct packet_sock_desc *sd;
+	int i, ret;
 
 	sd = (struct packet_sock_desc *)lookup_socket(p->stat.st_ino, PF_PACKET);
 	if (sd < 0)
@@ -67,7 +136,16 @@ static int dump_one_packet_fd(int lfd, u32 id, const struct fd_parms *p)
 	psk.vnet_hdr = (sd->nli.pdi_flags & PDI_VNETHDR ? true : false);
 	psk.loss = (sd->nli.pdi_flags & PDI_LOSS ? true : false);
 
-	return pb_write_one(fdset_fd(glob_fdset, CR_FD_PACKETSK), &psk, PB_PACKETSK);
+	ret = dump_mreqs(&psk, sd);
+	if (ret)
+		goto out;
+
+	ret = pb_write_one(fdset_fd(glob_fdset, CR_FD_PACKETSK), &psk, PB_PACKETSK);
+out:
+	for (i = 0; i < psk.n_mclist; i++)
+		xfree(psk.mclist[i]->addr.data);
+	xfree(psk.mclist);
+	return ret;
 }
 
 static const struct fdtype_ops packet_dump_ops = {
@@ -80,6 +158,18 @@ int dump_one_packet_sk(struct fd_parms *p, int lfd, const struct cr_fdset *fds)
 	return do_dump_gen_file(p, lfd, &packet_dump_ops, fds);
 }
 
+static int packet_save_mreqs(struct packet_sock_desc *sd, struct rtattr *mc)
+{
+	sd->mreq_n = RTA_PAYLOAD(mc) / sizeof(struct packet_diag_mclist);
+	pr_debug("\tGot %d mreqs\n", sd->mreq_n);
+	sd->mreqs = xmalloc(RTA_PAYLOAD(mc));
+	if (!sd->mreqs)
+		return -1;
+
+	memcpy(sd->mreqs, RTA_DATA(mc), RTA_PAYLOAD(mc));
+	return 0;
+}
+
 int packet_receive_one(struct nlmsghdr *hdr, void *arg)
 {
 	struct packet_diag_msg *m;
@@ -96,6 +186,11 @@ int packet_receive_one(struct nlmsghdr *hdr, void *arg)
 		return -1;
 	}
 
+	if (!tb[PACKET_DIAG_MCLIST]) {
+		pr_err("No packet sock mclist in nlm\n");
+		return -1;
+	}
+
 	sd = xmalloc(sizeof(*sd));
 	if (!sd)
 		return -1;
@@ -104,9 +199,40 @@ int packet_receive_one(struct nlmsghdr *hdr, void *arg)
 	sd->proto = htons(m->pdiag_num);
 	memcpy(&sd->nli, RTA_DATA(tb[PACKET_DIAG_INFO]), sizeof(sd->nli));
 
+	if (packet_save_mreqs(sd, tb[PACKET_DIAG_MCLIST]))
+		return -1;
+
 	return sk_collect_one(m->pdiag_ino, PF_PACKET, &sd->sd);
 }
 
+static int restore_mreqs(int sk, PacketSockEntry *pse)
+{
+	int i;
+
+	for (i = 0; i < pse->n_mclist; i++) {
+		PacketMclist *ml;
+		struct packet_mreq_max mreq;
+
+		ml = pse->mclist[i];
+		pr_info("Restoring mreq type %d\n", ml->type);
+
+		if (ml->addr.len > sizeof(mreq.mr_address)) {
+			pr_err("To big mcaddr %lu\n", ml->addr.len);
+			return -1;
+		}
+
+		mreq.mr_ifindex = ml->index;
+		mreq.mr_type = ml->type;
+		mreq.mr_alen = ml->addr.len;
+		memcpy(mreq.mr_address, ml->addr.data, ml->addr.len);
+
+		if (restore_opt(sk, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq))
+			return -1;
+	}
+
+	return 0;
+}
+
 static int open_packet_sk(struct file_desc *d)
 {
 	struct packet_sock_info *psi;
@@ -170,6 +296,9 @@ static int open_packet_sk(struct file_desc *d)
 			goto err_cl;
 	}
 
+	if (restore_mreqs(sk, pse))
+		goto err_cl;
+
 	if (rst_file_params(sk, pse->fown, pse->flags))
 		goto err_cl;
 

sockets.c

@@ -273,7 +273,7 @@ int collect_sockets(int pid)
 
 	req.r.p.sdiag_family	= AF_PACKET;
 	req.r.p.sdiag_protocol	= 0;
-	req.r.p.pdiag_show	= PACKET_SHOW_INFO;
+	req.r.p.pdiag_show	= PACKET_SHOW_INFO | PACKET_SHOW_MCLIST;
 	tmp = do_rtnl_req(nl, &req, sizeof(req), packet_receive_one, NULL);
 	if (tmp)
 		err = tmp;

test/zdtm/live/static/packet_sock.c

@@ -49,12 +49,26 @@ static int test_sockaddr(int n, struct sockaddr_ll *have, struct sockaddr_ll *wa
 	return 0;
 }
 
+#ifndef MAX_ADDR_LEN
+#define MAX_ADDR_LEN	32
+#endif
+
+struct packet_mreq_max {
+	int             mr_ifindex;
+	unsigned short  mr_type;
+	unsigned short  mr_alen;
+	unsigned char   mr_address[MAX_ADDR_LEN];
+};
+
+#define LO_ADDR_LEN	6
+
 int main(int argc, char **argv)
 {
 	int sk1, sk2;
 	struct sockaddr_ll addr, addr1, addr2;
 	socklen_t alen;
 	int ver, rsv, yes;
+	struct packet_mreq_max mreq;
 
 	test_init(argc, argv);
 
@@ -114,6 +128,23 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
+	memset(&mreq, 0, sizeof(mreq));
+	mreq.mr_ifindex = 1;
+	mreq.mr_type = PACKET_MR_PROMISC;
+	if (setsockopt(sk1, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
+		err("Can't add promisc member %m");
+		return 1;
+	}
+
+	memset(&mreq, 0, sizeof(mreq));
+	mreq.mr_ifindex = 1;
+	mreq.mr_type = PACKET_MR_UNICAST;
+	mreq.mr_alen = LO_ADDR_LEN;
+	if (setsockopt(sk2, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
+		err("Can't add ucast member %m");
+		return 1;
+	}
+
 	test_daemon();
 	test_waitsig();
 
@@ -148,6 +179,14 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
+	memset(&mreq, 0, sizeof(mreq));
+	mreq.mr_ifindex = 1;
+	mreq.mr_type = PACKET_MR_PROMISC;
+	if (setsockopt(sk1, SOL_PACKET, PACKET_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
+		fail("Promisc member not kept");
+		return 1;
+	}
+
 	alen = sizeof(addr);
 	if (getsockname(sk2, (struct sockaddr *)&addr, &alen) < 0) {
 		fail("Can't get sockname 2 rst");
@@ -179,6 +218,15 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
+	memset(&mreq, 0, sizeof(mreq));
+	mreq.mr_ifindex = 1;
+	mreq.mr_type = PACKET_MR_UNICAST;
+	mreq.mr_alen = LO_ADDR_LEN;
+	if (setsockopt(sk2, SOL_PACKET, PACKET_DROP_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
+		fail("Ucast member not kept");
+		return 1;
+	}
+
 	pass();
 	return 0;
 }