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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:53:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:53:30 +0000 |
commit | 2c7cac91ed6e7db0f6937923d2b57f97dbdbc337 (patch) | |
tree | c05dc0f8e6aa3accc84e3e5cffc933ed94941383 /lib/zlog_live.c | |
parent | Initial commit. (diff) | |
download | frr-upstream/8.4.4.tar.xz frr-upstream/8.4.4.zip |
Adding upstream version 8.4.4.upstream/8.4.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | lib/zlog_live.c | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/lib/zlog_live.c b/lib/zlog_live.c new file mode 100644 index 0000000..931aa34 --- /dev/null +++ b/lib/zlog_live.c @@ -0,0 +1,277 @@ +/* + * Copyright (c) 2019-22 David Lamparter, for NetDEF, Inc. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#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); +} |