Adding upstream version 9.1.upstream/9.1

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

1 files changed, 266 insertions, 0 deletions

diff --git a/lib/zlog_live.c b/lib/zlog_live.c
new file mode 100644
index 0000000..4d3c350
--- /dev/null
+++ b/lib/zlog_live.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: ISC
+/*
+ * Copyright (c) 2019-22  David Lamparter, for NetDEF, Inc.
+ */
+
+#include "zebra.h"
+
+#include "zlog_live.h"
+
+#include "memory.h"
+#include "frrcu.h"
+#include "zlog.h"
+#include "printfrr.h"
+#include "network.h"
+
+DEFINE_MTYPE_STATIC(LOG, LOG_LIVE, "log vtysh live target");
+
+enum {
+	STATE_NORMAL = 0,
+	STATE_FD_DEAD,
+	STATE_DISOWNED,
+};
+
+struct zlt_live {
+	struct zlog_target zt;
+
+	atomic_uint_fast32_t fd;
+	struct rcu_head_close head_close;
+	struct rcu_head head_self;
+
+	atomic_uint_fast32_t state;
+	atomic_uint_fast32_t lost_msgs;
+};
+
+static void zlog_live(struct zlog_target *zt, struct zlog_msg *msgs[],
+		      size_t nmsgs)
+{
+	struct zlt_live *zte = container_of(zt, struct zlt_live, zt);
+	struct zlog_live_hdr hdrs[nmsgs], *hdr = hdrs;
+	struct mmsghdr mmhs[nmsgs], *mmh = mmhs;
+	struct iovec iovs[nmsgs * 3], *iov = iovs;
+	struct timespec ts;
+	size_t i, textlen;
+	int fd;
+	uint_fast32_t state;
+
+	fd = atomic_load_explicit(&zte->fd, memory_order_relaxed);
+
+	if (fd < 0)
+		return;
+
+	memset(mmhs, 0, sizeof(mmhs));
+	memset(hdrs, 0, sizeof(hdrs));
+
+	for (i = 0; i < nmsgs; i++) {
+		const struct fmt_outpos *argpos;
+		size_t n_argpos, texthdrlen;
+		struct zlog_msg *msg = msgs[i];
+		int prio = zlog_msg_prio(msg);
+		const struct xref_logmsg *xref;
+		intmax_t pid, tid;
+
+		if (prio > zt->prio_min)
+			continue;
+
+		zlog_msg_args(msg, &texthdrlen, &n_argpos, &argpos);
+
+		mmh->msg_hdr.msg_iov = iov;
+
+		iov->iov_base = hdr;
+		iov->iov_len = sizeof(*hdr);
+		iov++;
+
+		if (n_argpos) {
+			iov->iov_base = (char *)argpos;
+			iov->iov_len = sizeof(*argpos) * n_argpos;
+			iov++;
+		}
+
+		iov->iov_base = (char *)zlog_msg_text(msg, &textlen);
+		iov->iov_len = textlen;
+		iov++;
+
+		zlog_msg_tsraw(msg, &ts);
+		zlog_msg_pid(msg, &pid, &tid);
+		xref = zlog_msg_xref(msg);
+
+		hdr->ts_sec = ts.tv_sec;
+		hdr->ts_nsec = ts.tv_nsec;
+		hdr->pid = pid;
+		hdr->tid = tid;
+		hdr->lost_msgs = atomic_load_explicit(&zte->lost_msgs,
+						      memory_order_relaxed);
+		hdr->prio = prio;
+		hdr->flags = 0;
+		hdr->textlen = textlen;
+		hdr->texthdrlen = texthdrlen;
+		hdr->n_argpos = n_argpos;
+		if (xref) {
+			memcpy(hdr->uid, xref->xref.xrefdata->uid,
+			       sizeof(hdr->uid));
+			hdr->ec = xref->ec;
+		} else {
+			memset(hdr->uid, 0, sizeof(hdr->uid));
+			hdr->ec = 0;
+		}
+		hdr->hdrlen = sizeof(*hdr) + sizeof(*argpos) * n_argpos;
+
+		mmh->msg_hdr.msg_iovlen = iov - mmh->msg_hdr.msg_iov;
+		mmh++;
+		hdr++;
+	}
+
+	size_t msgtotal = mmh - mmhs;
+	ssize_t sent;
+
+	for (size_t msgpos = 0; msgpos < msgtotal; msgpos += sent) {
+		sent = sendmmsg(fd, mmhs + msgpos, msgtotal - msgpos, 0);
+
+		if (sent <= 0 && (errno == EAGAIN || errno == EWOULDBLOCK)) {
+			atomic_fetch_add_explicit(&zte->lost_msgs,
+						  msgtotal - msgpos,
+						  memory_order_relaxed);
+			break;
+		}
+		if (sent <= 0)
+			goto out_err;
+	}
+	return;
+
+out_err:
+	fd = atomic_exchange_explicit(&zte->fd, -1, memory_order_relaxed);
+	if (fd < 0)
+		return;
+
+	rcu_close(&zte->head_close, fd);
+	zlog_target_replace(zt, NULL);
+
+	state = STATE_NORMAL;
+	atomic_compare_exchange_strong_explicit(
+		&zte->state, &state, STATE_FD_DEAD, memory_order_relaxed,
+		memory_order_relaxed);
+	if (state == STATE_DISOWNED)
+		rcu_free(MTYPE_LOG_LIVE, zte, head_self);
+}
+
+static void zlog_live_sigsafe(struct zlog_target *zt, const char *text,
+			      size_t len)
+{
+	struct zlt_live *zte = container_of(zt, struct zlt_live, zt);
+	struct zlog_live_hdr hdr[1] = {};
+	struct iovec iovs[2], *iov = iovs;
+	struct timespec ts;
+	int fd;
+
+	fd = atomic_load_explicit(&zte->fd, memory_order_relaxed);
+	if (fd < 0)
+		return;
+
+	clock_gettime(CLOCK_REALTIME, &ts);
+
+	hdr->ts_sec = ts.tv_sec;
+	hdr->ts_nsec = ts.tv_nsec;
+	hdr->prio = LOG_CRIT;
+	hdr->textlen = len;
+
+	iov->iov_base = (char *)hdr;
+	iov->iov_len = sizeof(hdr);
+	iov++;
+
+	iov->iov_base = (char *)text;
+	iov->iov_len = len;
+	iov++;
+
+	writev(fd, iovs, iov - iovs);
+}
+
+void zlog_live_open(struct zlog_live_cfg *cfg, int prio_min, int *other_fd)
+{
+	int sockets[2];
+
+	if (cfg->target)
+		zlog_live_close(cfg);
+
+	*other_fd = -1;
+	if (prio_min == ZLOG_DISABLED)
+		return;
+
+	/* the only reason for SEQPACKET here is getting close notifications.
+	 * otherwise if you open a bunch of vtysh connections with live logs
+	 * and close them all, the fds will stick around until we get an error
+	 * when trying to log something to them at some later point -- which
+	 * eats up fds and might be *much* later for some daemons.
+	 */
+	if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sockets) < 0) {
+		if (socketpair(AF_UNIX, SOCK_DGRAM, 0, sockets) < 0) {
+			zlog_warn("%% could not open socket pair: %m");
+			return;
+		}
+	} else
+		/* SEQPACKET only: try to zap read direction */
+		shutdown(sockets[0], SHUT_RD);
+
+	*other_fd = sockets[1];
+	zlog_live_open_fd(cfg, prio_min, sockets[0]);
+}
+
+void zlog_live_open_fd(struct zlog_live_cfg *cfg, int prio_min, int fd)
+{
+	struct zlt_live *zte;
+	struct zlog_target *zt;
+
+	if (cfg->target)
+		zlog_live_close(cfg);
+
+	zt = zlog_target_clone(MTYPE_LOG_LIVE, NULL, sizeof(*zte));
+	zte = container_of(zt, struct zlt_live, zt);
+	cfg->target = zte;
+
+	set_nonblocking(fd);
+	zte->fd = fd;
+	zte->zt.prio_min = prio_min;
+	zte->zt.logfn = zlog_live;
+	zte->zt.logfn_sigsafe = zlog_live_sigsafe;
+
+	zlog_target_replace(NULL, zt);
+}
+
+void zlog_live_close(struct zlog_live_cfg *cfg)
+{
+	struct zlt_live *zte;
+	int fd;
+
+	if (!cfg->target)
+		return;
+
+	zte = cfg->target;
+	cfg->target = NULL;
+
+	fd = atomic_exchange_explicit(&zte->fd, -1, memory_order_relaxed);
+
+	if (fd >= 0) {
+		rcu_close(&zte->head_close, fd);
+		zlog_target_replace(&zte->zt, NULL);
+	}
+	rcu_free(MTYPE_LOG_LIVE, zte, head_self);
+}
+
+void zlog_live_disown(struct zlog_live_cfg *cfg)
+{
+	struct zlt_live *zte;
+	uint_fast32_t state;
+
+	if (!cfg->target)
+		return;
+
+	zte = cfg->target;
+	cfg->target = NULL;
+
+	state = STATE_NORMAL;
+	atomic_compare_exchange_strong_explicit(
+		&zte->state, &state, STATE_DISOWNED, memory_order_relaxed,
+		memory_order_relaxed);
+	if (state == STATE_FD_DEAD)
+		rcu_free(MTYPE_LOG_LIVE, zte, head_self);
+}