--- /dev/null
+/**
+ * collectd - src/utils_taskstats.c
+ * Copyright (C) 2017 Florian octo Forster
+ *
+ * ISC License (ISC)
+ *
+ * Permission to use, copy, modify, and/or 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.
+ *
+ * Authors:
+ * Florian octo Forster <octo at collectd.org>
+ */
+
+#include "collectd.h"
+#include "utils_taskstats.h"
+
+#include "common.h"
+#include "plugin.h"
+#include "utils_time.h"
+
+#include <libmnl/libmnl.h>
+#include <linux/genetlink.h>
+#include <linux/taskstats.h>
+
+struct ts_s {
+ struct mnl_socket *nl;
+ pid_t pid;
+ uint32_t seq;
+ uint16_t genl_id_taskstats;
+ unsigned int port_id;
+};
+
+/* nlmsg_errno returns the errno encoded in nlh or zero if not an error. */
+static int nlmsg_errno(struct nlmsghdr *nlh, size_t sz) {
+ if (!mnl_nlmsg_ok(nlh, (int)sz)) {
+ ERROR("utils_taskstats: mnl_nlmsg_ok failed.");
+ return EPROTO;
+ }
+
+ if (nlh->nlmsg_type != NLMSG_ERROR) {
+ return 0;
+ }
+
+ struct nlmsgerr *nlerr = mnl_nlmsg_get_payload(nlh);
+ /* (struct nlmsgerr).error holds a negative errno. */
+ return nlerr->error * (-1);
+}
+
+static int get_taskstats_attr_cb(const struct nlattr *attr, void *data) {
+ struct taskstats *ret_taskstats = data;
+
+ uint16_t type = mnl_attr_get_type(attr);
+ switch (type) {
+ case TASKSTATS_TYPE_STATS:
+ if (mnl_attr_get_payload_len(attr) != sizeof(*ret_taskstats)) {
+ ERROR("utils_taskstats: mnl_attr_get_payload_len(attr) = %" PRIu32
+ ", want %zu",
+ mnl_attr_get_payload_len(attr), sizeof(*ret_taskstats));
+ return MNL_CB_ERROR;
+ }
+ struct taskstats *ts = mnl_attr_get_payload(attr);
+ memmove(ret_taskstats, ts, sizeof(*ret_taskstats));
+ return MNL_CB_OK;
+
+ case TASKSTATS_TYPE_AGGR_PID: /* fall through */
+ case TASKSTATS_TYPE_AGGR_TGID:
+ return mnl_attr_parse_nested(attr, get_taskstats_attr_cb, ret_taskstats);
+
+ case TASKSTATS_TYPE_PID: /* fall through */
+ case TASKSTATS_TYPE_TGID:
+ /* ignore */
+ return MNL_CB_OK;
+
+ default:
+ DEBUG("utils_taskstats: unknown attribute %" PRIu16
+ ", want one of TASKSTATS_TYPE_AGGR_PID/TGID, TASKSTATS_TYPE_STATS",
+ type);
+ }
+ return MNL_CB_OK;
+}
+
+static int get_taskstats_msg_cb(const struct nlmsghdr *nlh, void *data) {
+ return mnl_attr_parse(nlh, sizeof(struct genlmsghdr), get_taskstats_attr_cb,
+ data);
+}
+
+static int get_taskstats(ts_t *ts, uint32_t tgid,
+ struct taskstats *ret_taskstats) {
+ char buffer[MNL_SOCKET_BUFFER_SIZE];
+ uint32_t seq = ts->seq++;
+
+ struct nlmsghdr *nlh = mnl_nlmsg_put_header(buffer);
+ *nlh = (struct nlmsghdr){
+ .nlmsg_len = nlh->nlmsg_len,
+ .nlmsg_type = ts->genl_id_taskstats,
+ .nlmsg_flags = NLM_F_REQUEST,
+ .nlmsg_seq = seq,
+ .nlmsg_pid = ts->pid,
+ };
+
+ struct genlmsghdr *genh = mnl_nlmsg_put_extra_header(nlh, sizeof(*genh));
+ *genh = (struct genlmsghdr){
+ .cmd = TASKSTATS_CMD_GET,
+ .version = TASKSTATS_GENL_VERSION, // or TASKSTATS_VERSION?
+ };
+
+ // mnl_attr_put_u32(nlh, TASKSTATS_CMD_ATTR_PID, tgid);
+ mnl_attr_put_u32(nlh, TASKSTATS_CMD_ATTR_TGID, tgid);
+
+ if (mnl_socket_sendto(ts->nl, nlh, nlh->nlmsg_len) < 0) {
+ int status = errno;
+ ERROR("utils_taskstats: mnl_socket_sendto() = %s", STRERROR(status));
+ return status;
+ }
+
+ int status = mnl_socket_recvfrom(ts->nl, buffer, sizeof(buffer));
+ if (status < 0) {
+ status = errno;
+ ERROR("utils_taskstats: mnl_socket_recvfrom() = %s", STRERROR(status));
+ return status;
+ } else if (status == 0) {
+ ERROR("utils_taskstats: mnl_socket_recvfrom() = 0");
+ return ECONNABORTED;
+ }
+ size_t buffer_size = (size_t)status;
+
+ if ((status = nlmsg_errno((void *)buffer, buffer_size)) != 0) {
+ ERROR("utils_taskstats: TASKSTATS_CMD_GET(TASKSTATS_CMD_ATTR_TGID = "
+ "%" PRIu32 ") = %s",
+ (uint32_t)tgid, STRERROR(status));
+ return status;
+ }
+
+ status = mnl_cb_run(buffer, buffer_size, seq, ts->port_id,
+ get_taskstats_msg_cb, ret_taskstats);
+ if (status < MNL_CB_STOP) {
+ ERROR("utils_taskstats: Parsing message failed.");
+ return EPROTO;
+ }
+
+ return 0;
+}
+
+static int get_family_id_attr_cb(const struct nlattr *attr, void *data) {
+ uint16_t type = mnl_attr_get_type(attr);
+ if (type != CTRL_ATTR_FAMILY_ID) {
+ return MNL_CB_OK;
+ }
+
+ if (mnl_attr_validate(attr, MNL_TYPE_U16) < 0) {
+ ERROR("mnl_attr_validate() = %s", STRERRNO);
+ return MNL_CB_ERROR;
+ }
+
+ uint16_t *ret_family_id = data;
+ *ret_family_id = mnl_attr_get_u16(attr);
+ return MNL_CB_STOP;
+}
+
+static int get_family_id_msg_cb(const struct nlmsghdr *nlh, void *data) {
+ return mnl_attr_parse(nlh, sizeof(struct genlmsghdr), get_family_id_attr_cb,
+ data);
+}
+
+/* get_family_id initializes ts->genl_id_taskstats. Returns 0 on success and
+ * an error code otherwise. */
+static int get_family_id(ts_t *ts) {
+ char buffer[MNL_SOCKET_BUFFER_SIZE];
+ uint32_t seq = ts->seq++;
+
+ struct nlmsghdr *nlh = mnl_nlmsg_put_header(buffer);
+ *nlh = (struct nlmsghdr){
+ .nlmsg_len = nlh->nlmsg_len,
+ .nlmsg_type = GENL_ID_CTRL,
+ .nlmsg_flags = NLM_F_REQUEST,
+ .nlmsg_seq = seq,
+ .nlmsg_pid = ts->pid,
+ };
+
+ struct genlmsghdr *genh = mnl_nlmsg_put_extra_header(nlh, sizeof(*genh));
+ *genh = (struct genlmsghdr){
+ .cmd = CTRL_CMD_GETFAMILY, .version = 0x01,
+ };
+
+ mnl_attr_put_strz(nlh, CTRL_ATTR_FAMILY_NAME, TASKSTATS_GENL_NAME);
+
+ assert(genh->cmd == CTRL_CMD_GETFAMILY);
+ assert(genh->version == TASKSTATS_GENL_VERSION);
+
+ if (mnl_socket_sendto(ts->nl, nlh, nlh->nlmsg_len) < 0) {
+ int status = errno;
+ ERROR("utils_taskstats: mnl_socket_sendto() = %s", STRERROR(status));
+ return status;
+ }
+
+ ts->genl_id_taskstats = 0;
+ while (42) {
+ int status = mnl_socket_recvfrom(ts->nl, buffer, sizeof(buffer));
+ if (status < 0) {
+ status = errno;
+ ERROR("utils_taskstats: mnl_socket_recvfrom() = %s", STRERROR(status));
+ return status;
+ } else if (status == 0) {
+ break;
+ }
+ size_t buffer_size = (size_t)status;
+
+ if ((status = nlmsg_errno((void *)buffer, buffer_size)) != 0) {
+ ERROR("utils_taskstats: CTRL_CMD_GETFAMILY(\"%s\"): %s",
+ TASKSTATS_GENL_NAME, STRERROR(status));
+ return status;
+ }
+
+ status = mnl_cb_run(buffer, buffer_size, seq, ts->port_id,
+ get_family_id_msg_cb, &ts->genl_id_taskstats);
+ if (status < MNL_CB_STOP) {
+ ERROR("utils_taskstats: Parsing message failed.");
+ return EPROTO;
+ } else if (status == MNL_CB_STOP) {
+ break;
+ }
+ }
+
+ if (ts->genl_id_taskstats == 0) {
+ ERROR("utils_taskstats: Netlink communication succeeded, but "
+ "genl_id_taskstats is still zero.");
+ return ENOENT;
+ }
+
+ return 0;
+}
+
+void ts_destroy(ts_t *ts) {
+ if (ts == NULL) {
+ return;
+ }
+
+ if (ts->nl != NULL) {
+ mnl_socket_close(ts->nl);
+ ts->nl = NULL;
+ }
+
+ sfree(ts);
+}
+
+ts_t *ts_create(void) {
+ ts_t *ts = calloc(1, sizeof(*ts));
+ if (ts == NULL) {
+ ERROR("utils_taskstats: calloc failed: %s", STRERRNO);
+ return NULL;
+ }
+
+ if ((ts->nl = mnl_socket_open(NETLINK_GENERIC)) == NULL) {
+ ERROR("utils_taskstats: mnl_socket_open(NETLINK_GENERIC) = %s", STRERRNO);
+ ts_destroy(ts);
+ return NULL;
+ }
+
+ if (mnl_socket_bind(ts->nl, 0, MNL_SOCKET_AUTOPID) != 0) {
+ ERROR("utils_taskstats: mnl_socket_bind() = %s", STRERRNO);
+ ts_destroy(ts);
+ return NULL;
+ }
+
+ ts->pid = getpid();
+ ts->port_id = mnl_socket_get_portid(ts->nl);
+
+ int status = get_family_id(ts);
+ if (status != 0) {
+ ERROR("utils_taskstats: get_family_id() = %s", STRERROR(status));
+ ts_destroy(ts);
+ return NULL;
+ }
+
+ return ts;
+}
+
+int ts_delay_by_tgid(ts_t *ts, uint32_t tgid, ts_delay_t *out) {
+ if ((ts == NULL) || (out == NULL)) {
+ return EINVAL;
+ }
+
+ struct taskstats raw = {0};
+
+ int status = get_taskstats(ts, tgid, &raw);
+ if (status != 0) {
+ return status;
+ }
+
+ *out = (ts_delay_t){
+ .cpu_ns = raw.cpu_delay_total,
+ .blkio_ns = raw.blkio_delay_total,
+ .swapin_ns = raw.swapin_delay_total,
+ .freepages_ns = raw.freepages_delay_total,
+ };
+ return 0;
+}
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