diff --git a/lib/subdir.am b/lib/subdir.am index db11def74197..c621ad06584e 100644 --- a/lib/subdir.am +++ b/lib/subdir.am @@ -131,6 +131,7 @@ lib_libfrr_la_SOURCES = \ lib/zlog_5424.c \ lib/zlog_5424_cli.c \ lib/zlog_live.c \ + lib/zlog_recirculate.c \ lib/zlog_targets.c \ lib/printf/printf-pos.c \ lib/printf/vfprintf.c \ @@ -329,6 +330,7 @@ pkginclude_HEADERS += \ lib/zlog.h \ lib/zlog_5424.h \ lib/zlog_live.h \ + lib/zlog_recirculate.h \ lib/zlog_targets.h \ lib/pbr.h \ lib/tc.h \ diff --git a/lib/zlog.c b/lib/zlog.c index 8734fd55af3e..ffca5726095b 100644 --- a/lib/zlog.c +++ b/lib/zlog.c @@ -50,6 +50,7 @@ #include "printfrr.h" #include "frrcu.h" #include "zlog.h" +#include "zlog_live.h" #include "libfrr_trace.h" #include "frrevent.h" @@ -109,6 +110,9 @@ struct zlog_msg { size_t textlen; size_t hdrlen; + /* for relayed log messages ONLY (cf. zlog_recirculate_live_msg) */ + intmax_t pid, tid; + /* This is always ISO8601 with sub-second precision 9 here, it's * converted for callers as needed. ts_dot points to the "." * separating sub-seconds. ts_zonetail is "Z" or "+00:00" for the @@ -357,6 +361,16 @@ void zlog_msg_pid(struct zlog_msg *msg, intmax_t *pid, intmax_t *tid) { #ifndef __OpenBSD__ static thread_local intmax_t cached_pid = -1; +#endif + + /* recirculated messages */ + if (msg->pid) { + *pid = msg->pid; + *tid = msg->tid; + return; + } + +#ifndef __OpenBSD__ if (cached_pid != -1) *pid = cached_pid; else @@ -507,6 +521,89 @@ static void vzlog_tls(struct zlog_tls *zlog_tls, const struct xref_logmsg *xref, XFREE(MTYPE_LOG_MESSAGE, msg->text); } +/* reinject log message received by zlog_recirculate_recv(). As of writing, + * only used in the ldpd parent process to proxy messages from lde/ldpe + * subprocesses. + */ +void zlog_recirculate_live_msg(uint8_t *data, size_t len) +{ + struct zlog_target *zt; + struct zlog_msg stackmsg = {}, *msg = &stackmsg; + struct zlog_live_hdr *hdr; + struct xrefdata *xrefdata, ref = {}; + + if (len < sizeof(*hdr)) + return; + + hdr = (struct zlog_live_hdr *)data; + if (hdr->hdrlen < sizeof(*hdr)) + return; + data += hdr->hdrlen; + len -= sizeof(*hdr); + + msg->ts.tv_sec = hdr->ts_sec; + msg->ts.tv_nsec = hdr->ts_nsec; + msg->pid = hdr->pid; + msg->tid = hdr->tid; + msg->prio = hdr->prio; + + if (hdr->textlen > len) + return; + msg->textlen = hdr->textlen; + msg->hdrlen = hdr->texthdrlen; + msg->text = (char *)data; + + /* caller needs to make sure we have a trailing \n\0, it's not + * transmitted on zlog_live + */ + if (msg->text[msg->textlen] != '\n' || + msg->text[msg->textlen + 1] != '\0') + return; + + static_assert(sizeof(msg->argpos[0]) == sizeof(hdr->argpos[0]), + "in-memory struct doesn't match on-wire variant"); + msg->n_argpos = MIN(hdr->n_argpos, array_size(msg->argpos)); + memcpy(msg->argpos, hdr->argpos, msg->n_argpos * sizeof(msg->argpos[0])); + + /* This will only work if we're in the same daemon: we received a log + * message uid and are now doing a lookup in *our* known uids to find + * it. This works for ldpd because it's the same binary containing the + * same log messages, and ldpd is the only use case right now. + * + * When the uid is not found, the log message uid is lost but the + * message itself is still processed correctly. If this is needed, + * this can be made to work in two ways: + * (a) synthesize a temporary xref_logmsg from the received data. + * This is a bit annoying due to lifetimes with per-thread buffers. + * (b) extract and aggregate all log messages. This already happens + * with frr.xref but that would need to be fed back in. + */ + strlcpy(ref.uid, hdr->uid, sizeof(ref.uid)); + xrefdata = xrefdata_uid_find(&xrefdata_uid, &ref); + + if (xrefdata && xrefdata->xref->type == XREFT_LOGMSG) { + struct xref_logmsg *xref_logmsg; + + xref_logmsg = (struct xref_logmsg *)xrefdata->xref; + msg->xref = xref_logmsg; + msg->fmt = xref_logmsg->fmtstring; + } else { + /* fake out format string... */ + msg->fmt = msg->text + hdr->texthdrlen; + } + + rcu_read_lock(); + frr_each_safe (zlog_targets, &zlog_targets, zt) { + if (msg->prio > zt->prio_min) + continue; + if (!zt->logfn) + continue; + + zt->logfn(zt, &msg, 1); + } + rcu_read_unlock(); +} + static void zlog_backtrace_msg(const struct xref_logmsg *xref, int prio) { struct event *tc = pthread_getspecific(thread_current); diff --git a/lib/zlog.h b/lib/zlog.h index 27401d51fb13..9d9397995778 100644 --- a/lib/zlog.h +++ b/lib/zlog.h @@ -125,6 +125,9 @@ static inline void zlog_ref(const struct xref_logmsg *xref, extern void zlog_sigsafe(const char *text, size_t len); +/* recirculate a log message from zlog_live */ +extern void zlog_recirculate_live_msg(uint8_t *data, size_t len); + /* extra priority value to disable a target without deleting it */ #define ZLOG_DISABLED (LOG_EMERG-1) diff --git a/lib/zlog_recirculate.c b/lib/zlog_recirculate.c new file mode 100644 index 000000000000..abc73eeed007 --- /dev/null +++ b/lib/zlog_recirculate.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: ISC +/* + * Copyright (c) 2024 David Lamparter, for NetDEF, Inc. + */ + +#include "zebra.h" + +#include "log.h" +#include "frrevent.h" + +#include "zlog_recirculate.h" + +/* This is only the event loop part; it's split off from + * zlog_recirculate_live_msg since there's an integration boundary; this + * half deals with events, the other half with zlog interna. + * + * As of writing, this runs in ldpd in the *parent* process and receives log + * messages from the lde/ldpe subprocesses. It is not used anywhere else + * (yet?) + */ +static void zlog_recirculate_recv(struct event *ev) +{ + uint8_t rxbuf[4096]; + ssize_t n_rd; + int fd = EVENT_FD(ev); + + /* see below for -2, "\n\0" are added */ + n_rd = read(fd, rxbuf, sizeof(rxbuf) - 2); + if (n_rd == 0) { + /* EOF */ + close(fd); + /* event_add_read not called yet, nothing to cancel */ + return; + } + if (n_rd < 0 && (errno != EAGAIN) && (errno != EWOULDBLOCK)) { + /* error */ + zlog_warn("error on log relay socket %d: %m", fd); + close(fd); + /* event_add_read not called yet, nothing to cancel */ + return; + } + + event_add_read(ev->master, zlog_recirculate_recv, NULL, fd, NULL); + if (n_rd < 0) + return; + + /* log infrastructure has an implicit \n\0 at the end */ + rxbuf[n_rd] = '\n'; + rxbuf[n_rd + 1] = '\0'; + zlog_recirculate_live_msg(rxbuf, n_rd); +} + +void zlog_recirculate_subscribe(struct event_loop *el, int fd) +{ + event_add_read(el, zlog_recirculate_recv, NULL, fd, NULL); +} diff --git a/lib/zlog_recirculate.h b/lib/zlog_recirculate.h new file mode 100644 index 000000000000..a2ddb4e172d0 --- /dev/null +++ b/lib/zlog_recirculate.h @@ -0,0 +1,12 @@ +// SPDX-License-Identifier: ISC +/* + * Copyright (c) 2024 David Lamparter, for NetDEF, Inc. + */ + +#ifndef _FRR_ZLOG_RECIRCULATE_H +#define _FRR_ZLOG_RECIRCULATE_H + +/* fd should be one end of a socketpair() */ +extern void zlog_recirculate_subscribe(struct event_loop *tm, int fd); + +#endif