Adding upstream version 9.1.upstream/9.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 351 insertions, 0 deletions

diff --git a/zebra/zebra_netns_id.c b/zebra/zebra_netns_id.c
new file mode 100644
index 0000000..0531ab9
--- /dev/null
+++ b/zebra/zebra_netns_id.c
@@ -0,0 +1,351 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* zebra NETNS ID handling routines
+ * those routines are implemented locally to avoid having external dependencies.
+ * Copyright (C) 2018 6WIND
+ */
+
+#include <zebra.h>
+
+#include "ns.h"
+#include "vrf.h"
+#include "log.h"
+#include "lib_errors.h"
+#include "network.h"
+
+#include "zebra/rib.h"
+#include "zebra/zebra_dplane.h"
+#if defined(HAVE_NETLINK)
+
+#include <linux/net_namespace.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+#include "zebra_ns.h"
+#include "kernel_netlink.h"
+#endif /* defined(HAVE_NETLINK) */
+
+#include "zebra/zebra_netns_id.h"
+#include "zebra/zebra_errors.h"
+
+/* in case NEWNSID not available, the NSID will be locally obtained
+ */
+#define NS_BASE_NSID 0
+
+#if defined(HAVE_NETLINK)
+
+#define NETLINK_SOCKET_BUFFER_SIZE 512
+#define NETLINK_ALIGNTO             4
+#define NETLINK_ALIGN(len)                                                     \
+	(((len) + NETLINK_ALIGNTO - 1) & ~(NETLINK_ALIGNTO - 1))
+#define NETLINK_NLATTR_LEN(_a, _b)   (unsigned int)((char *)_a - (char *)_b)
+
+#endif /* defined(HAVE_NETLINK) */
+
+static ns_id_t zebra_ns_id_get_fallback(const char *netnspath)
+{
+	static int zebra_ns_id_local;
+
+	return zebra_ns_id_local++;
+}
+
+#if defined(HAVE_NETLINK)
+
+static struct nlmsghdr *initiate_nlh(char *buf, unsigned int *seq, int type)
+{
+	struct nlmsghdr *nlh;
+
+	nlh = (struct nlmsghdr *)buf;
+	nlh->nlmsg_len = NETLINK_ALIGN(sizeof(struct nlmsghdr));
+
+	nlh->nlmsg_type = type;
+	nlh->nlmsg_flags = NLM_F_REQUEST;
+	if (type == RTM_NEWNSID)
+		nlh->nlmsg_flags |= NLM_F_ACK;
+	nlh->nlmsg_seq = *seq = frr_sequence32_next();
+	return nlh;
+}
+
+static int send_receive(int sock, struct nlmsghdr *nlh, unsigned int seq,
+			char *buf)
+{
+	int ret;
+	static const struct sockaddr_nl snl = {.nl_family = AF_NETLINK};
+
+	ret = sendto(sock, (const void *)nlh, (size_t)nlh->nlmsg_len, 0,
+		     (struct sockaddr *)&snl, (socklen_t)sizeof(snl));
+	if (ret < 0) {
+		flog_err_sys(EC_LIB_SOCKET, "netlink( %u) sendmsg() error: %s",
+			     sock, safe_strerror(errno));
+		return -1;
+	}
+
+	/* reception */
+	struct sockaddr_nl addr;
+	struct iovec iov = {
+		.iov_base = buf, .iov_len = NETLINK_SOCKET_BUFFER_SIZE,
+	};
+	struct msghdr msg = {
+		.msg_name = &addr,
+		.msg_namelen = sizeof(struct sockaddr_nl),
+		.msg_iov = &iov,
+		.msg_iovlen = 1,
+		.msg_control = NULL,
+		.msg_controllen = 0,
+		.msg_flags = 0,
+	};
+	ret = recvmsg(sock, &msg, 0);
+	if (ret < 0) {
+		flog_err_sys(EC_LIB_SOCKET,
+			     "netlink recvmsg: error %d (errno %u)", ret,
+			     errno);
+		return -1;
+	}
+	if (msg.msg_flags & MSG_TRUNC) {
+		flog_err(EC_ZEBRA_NETLINK_LENGTH_ERROR,
+			 "netlink recvmsg : error message truncated");
+		return -1;
+	}
+	/* nlh already points to buf */
+	if (nlh->nlmsg_seq != seq) {
+		flog_err(
+			EC_ZEBRA_NETLINK_BAD_SEQUENCE,
+			"netlink recvmsg: bad sequence number %x (expected %x)",
+			seq, nlh->nlmsg_seq);
+		return -1;
+	}
+	return ret;
+}
+
+/* extract on a valid nlmsg the nsid
+ * valid nlmsghdr - not a nlmsgerr
+ */
+static ns_id_t extract_nsid(struct nlmsghdr *nlh, char *buf)
+{
+	ns_id_t ns_id = NS_UNKNOWN;
+	int offset = NETLINK_ALIGN(sizeof(struct nlmsghdr))
+		     + NETLINK_ALIGN(sizeof(struct rtgenmsg));
+	void *tail = (void *)((char *)nlh + NETLINK_ALIGN(nlh->nlmsg_len));
+	struct nlattr *attr;
+
+	for (attr = (struct nlattr *)(buf + offset);
+	     NETLINK_NLATTR_LEN(tail, attr) >= sizeof(struct nlattr)
+	     && attr->nla_len >= sizeof(struct nlattr)
+	     && attr->nla_len <= NETLINK_NLATTR_LEN(tail, attr);
+	     attr += NETLINK_ALIGN(attr->nla_len)) {
+		if ((attr->nla_type & NLA_TYPE_MASK) == NETNSA_NSID) {
+			uint32_t *ptr = (uint32_t *)(attr);
+
+			ns_id = ptr[1];
+			break;
+		}
+	}
+	return ns_id;
+}
+
+/* fd_param = -1 is ignored.
+ * netnspath set to null is ignored.
+ * one of the 2 params is mandatory. netnspath is looked in priority
+ */
+ns_id_t zebra_ns_id_get(const char *netnspath, int fd_param)
+{
+	int ns_id = -1;
+	struct sockaddr_nl snl;
+	int fd = -1, sock, ret;
+	unsigned int seq;
+	ns_id_t return_nsid = NS_UNKNOWN;
+
+	/* netns path check */
+	if (!netnspath && fd_param == -1)
+		return NS_UNKNOWN;
+	if (netnspath)  {
+		fd = open(netnspath, O_RDONLY);
+		if (fd == -1)
+			return NS_UNKNOWN;
+	} else if (fd_param != -1)
+		fd = fd_param;
+	/* netlink socket */
+	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+	if (sock < 0) {
+		flog_err_sys(EC_LIB_SOCKET, "netlink( %u) socket() error: %s",
+			     sock, safe_strerror(errno));
+		if (netnspath)
+			close(fd);
+		return NS_UNKNOWN;
+	}
+	memset(&snl, 0, sizeof(snl));
+	snl.nl_family = AF_NETLINK;
+	snl.nl_groups = RTNLGRP_NSID;
+	snl.nl_pid = 0; /* AUTO PID */
+	ret = bind(sock, (struct sockaddr *)&snl, sizeof(snl));
+	if (ret < 0) {
+		flog_err_sys(EC_LIB_SOCKET,
+			     "netlink( %u) socket() bind error: %s", sock,
+			     safe_strerror(errno));
+		close(sock);
+		if (netnspath)
+			close(fd);
+		return NS_UNKNOWN;
+	}
+
+	/* message to send to netlink,and response : NEWNSID */
+	char buf[NETLINK_SOCKET_BUFFER_SIZE];
+	struct nlmsghdr *nlh;
+	struct rtgenmsg *rt;
+	int len;
+
+	memset(buf, 0, NETLINK_SOCKET_BUFFER_SIZE);
+	nlh = initiate_nlh(buf, &seq, RTM_NEWNSID);
+	rt = (struct rtgenmsg *)(buf + nlh->nlmsg_len);
+	nlh->nlmsg_len += NETLINK_ALIGN(sizeof(struct rtgenmsg));
+	rt->rtgen_family = AF_UNSPEC;
+
+	nl_attr_put32(nlh, NETLINK_SOCKET_BUFFER_SIZE, NETNSA_FD, fd);
+	nl_attr_put32(nlh, NETLINK_SOCKET_BUFFER_SIZE, NETNSA_NSID, ns_id);
+
+	ret = send_receive(sock, nlh, seq, buf);
+	if (ret < 0) {
+		close(sock);
+		if (netnspath)
+			close(fd);
+		return NS_UNKNOWN;
+	}
+	nlh = (struct nlmsghdr *)buf;
+
+	/* message to analyse : NEWNSID response */
+	ret = 0;
+	if (nlh->nlmsg_type >= NLMSG_MIN_TYPE) {
+		return_nsid = extract_nsid(nlh, buf);
+	} else {
+		if (nlh->nlmsg_type == NLMSG_ERROR) {
+			struct nlmsgerr *err =
+				(struct nlmsgerr
+					 *)((char *)nlh
+					    + NETLINK_ALIGN(
+						      sizeof(struct nlmsghdr)));
+
+			ret = -1;
+			if (err->error < 0)
+				errno = -err->error;
+			else
+				errno = err->error;
+			if (errno == 0) {
+				/* request NEWNSID was successfull
+				 * return EEXIST error to get GETNSID
+				 */
+				errno = EEXIST;
+			}
+		} else {
+			/* other errors ignored
+			 * attempt to get nsid
+			 */
+			ret = -1;
+			errno = EEXIST;
+		}
+	}
+
+	if (errno != EEXIST && ret != 0) {
+		flog_err(EC_LIB_SOCKET,
+			 "netlink( %u) recvfrom() error 2 when reading: %s", fd,
+			 safe_strerror(errno));
+		close(sock);
+		if (netnspath)
+			close(fd);
+		if (errno == ENOTSUP) {
+			zlog_debug("NEWNSID locally generated");
+			return zebra_ns_id_get_fallback(netnspath);
+		}
+		return NS_UNKNOWN;
+	}
+	/* message to send to netlink : GETNSID */
+	memset(buf, 0, NETLINK_SOCKET_BUFFER_SIZE);
+	nlh = initiate_nlh(buf, &seq, RTM_GETNSID);
+	rt = (struct rtgenmsg *)(buf + nlh->nlmsg_len);
+	nlh->nlmsg_len += NETLINK_ALIGN(sizeof(struct rtgenmsg));
+	rt->rtgen_family = AF_UNSPEC;
+
+	nl_attr_put32(nlh, NETLINK_SOCKET_BUFFER_SIZE, NETNSA_FD, fd);
+	nl_attr_put32(nlh, NETLINK_SOCKET_BUFFER_SIZE, NETNSA_NSID, ns_id);
+
+	ret = send_receive(sock, nlh, seq, buf);
+	if (ret < 0) {
+		close(sock);
+		if (netnspath)
+			close(fd);
+		return NS_UNKNOWN;
+	}
+	nlh = (struct nlmsghdr *)buf;
+	len = ret;
+	ret = 0;
+	do {
+		if (nlh->nlmsg_type >= NLMSG_MIN_TYPE) {
+			return_nsid = extract_nsid(nlh, buf);
+			if (return_nsid != NS_UNKNOWN)
+				break;
+		} else if (nlh->nlmsg_type == NLMSG_ERROR) {
+			struct nlmsgerr *err =
+				(struct nlmsgerr *)((char *)nlh +
+						    NETLINK_ALIGN(sizeof(
+							    struct nlmsghdr)));
+			if (err->error < 0)
+				errno = -err->error;
+			else
+				errno = err->error;
+			break;
+		}
+		len = len - NETLINK_ALIGN(nlh->nlmsg_len);
+		nlh = (struct nlmsghdr *)((char *)nlh +
+					  NETLINK_ALIGN(nlh->nlmsg_len));
+	} while (len != 0 && ret == 0);
+
+	if (netnspath)
+		close(fd);
+	close(sock);
+	return return_nsid;
+}
+
+#else
+ns_id_t zebra_ns_id_get(const char *netnspath, int fd __attribute__ ((unused)))
+{
+	return zebra_ns_id_get_fallback(netnspath);
+}
+
+#endif /* ! defined(HAVE_NETLINK) */
+
+#ifdef HAVE_NETNS
+static void zebra_ns_create_netns_directory(void)
+{
+	/* check that /var/run/netns is created */
+	/* S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH */
+	if (mkdir(NS_RUN_DIR, 0755)) {
+		if (errno != EEXIST) {
+			flog_warn(EC_ZEBRA_NAMESPACE_DIR_INACCESSIBLE,
+				  "NS check: failed to access %s", NS_RUN_DIR);
+			return;
+		}
+	}
+}
+#endif
+
+ns_id_t zebra_ns_id_get_default(void)
+{
+#ifdef HAVE_NETNS
+	int fd;
+#endif /* !HAVE_NETNS */
+
+#ifdef HAVE_NETNS
+	if (vrf_is_backend_netns())
+		zebra_ns_create_netns_directory();
+	fd = open(NS_DEFAULT_NAME, O_RDONLY);
+
+	if (fd == -1)
+		return NS_DEFAULT;
+	if (!vrf_is_backend_netns()) {
+		close(fd);
+		return NS_DEFAULT;
+	}
+	close(fd);
+	return zebra_ns_id_get((char *)NS_DEFAULT_NAME, -1);
+#else  /* HAVE_NETNS */
+	return NS_DEFAULT;
+#endif /* !HAVE_NETNS */
+}