+++ /dev/null
-/* libltt
- *
- * Linux Trace Toolkit Netlink Control Library
- *
- * Controls the ltt-control kernel module through a netlink socket.
- *
- * Heavily inspired from libipq.c (iptables) made by
- * James Morris <jmorris@intercode.com.au>
- *
- * Copyright 2005 -
- * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- */
-
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
-
-#include <liblttctl/lttctl.h>
-#include <errno.h>
-#include <stdio.h>
-#include <error.h>
-#include <stdlib.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include <string.h>
-
-
-
-/* Private interface */
-
-enum {
- LTTCTL_ERR_NONE = 0,
- LTTCTL_ERR_IMPL,
- LTTCTL_ERR_HANDLE,
- LTTCTL_ERR_SOCKET,
- LTTCTL_ERR_BIND,
- LTTCTL_ERR_BUFFER,
- LTTCTL_ERR_RECV,
- LTTCTL_ERR_NLEOF,
- LTTCTL_ERR_ADDRLEN,
- LTTCTL_ERR_STRUNC,
- LTTCTL_ERR_RTRUNC,
- LTTCTL_ERR_NLRECV,
- LTTCTL_ERR_SEND,
- LTTCTL_ERR_SUPP,
- LTTCTL_ERR_RECVBUF,
- LTTCTL_ERR_TIMEOUT,
- LTTCTL_ERR_PROTOCOL
-};
-#define LTTCTL_MAXERR LTTCTL_ERR_PROTOCOL
-
-
-struct lttctl_errmap_t {
- int errcode;
- char *message;
-} lttctl_errmap[] = {
- { LTTCTL_ERR_NONE, "Unknown error" },
- { LTTCTL_ERR_IMPL, "Implementation error" },
- { LTTCTL_ERR_HANDLE, "Unable to create netlink handle" },
- { LTTCTL_ERR_SOCKET, "Unable to create netlink socket" },
- { LTTCTL_ERR_BIND, "Unable to bind netlink socket" },
- { LTTCTL_ERR_BUFFER, "Unable to allocate buffer" },
- { LTTCTL_ERR_RECV, "Failed to receive netlink message" },
- { LTTCTL_ERR_NLEOF, "Received EOF on netlink socket" },
- { LTTCTL_ERR_ADDRLEN, "Invalid peer address length" },
- { LTTCTL_ERR_STRUNC, "Sent message truncated" },
- { LTTCTL_ERR_RTRUNC, "Received message truncated" },
- { LTTCTL_ERR_NLRECV, "Received error from netlink" },
- { LTTCTL_ERR_SEND, "Failed to send netlink message" },
- { LTTCTL_ERR_SUPP, "Operation not supported" },
- { LTTCTL_ERR_RECVBUF, "Receive buffer size invalid" },
- { LTTCTL_ERR_TIMEOUT, "Timeout"},
- { LTTCTL_ERR_PROTOCOL, "Invalid protocol specified" }
-};
-
-static int lttctl_errno = LTTCTL_ERR_NONE;
-
-
-static ssize_t lttctl_netlink_sendto(const struct lttctl_handle *h,
- const void *msg, size_t len);
-
-static ssize_t lttctl_netlink_recvfrom(const struct lttctl_handle *h,
- unsigned char *buf, size_t len,
- int timeout);
-
-static ssize_t lttctl_netlink_sendmsg(const struct lttctl_handle *h,
- const struct msghdr *msg,
- unsigned int flags);
-
-static char *lttctl_strerror(int errcode);
-
-void lttctl_perror(const char *s);
-
-static ssize_t lttctl_netlink_sendto(const struct lttctl_handle *h,
- const void *msg, size_t len)
-{
- int status = sendto(h->fd, msg, len, 0,
- (struct sockaddr *)&h->peer, sizeof(h->peer));
- if (status < 0)
- lttctl_errno = LTTCTL_ERR_SEND;
-
- return status;
-}
-
-static ssize_t lttctl_netlink_sendmsg(const struct lttctl_handle *h,
- const struct msghdr *msg,
- unsigned int flags)
-{
- int status = sendmsg(h->fd, msg, flags);
- if (status < 0)
- lttctl_errno = LTTCTL_ERR_SEND;
- return status;
-}
-
-static ssize_t lttctl_netlink_recvfrom(const struct lttctl_handle *h,
- unsigned char *buf, size_t len,
- int timeout)
-{
- int addrlen, status;
- struct nlmsghdr *nlh;
-
- if (len < sizeof(struct nlmsghdr)) {
- lttctl_errno = LTTCTL_ERR_RECVBUF;
- lttctl_perror("Netlink recvfrom");
- return -1;
- }
- addrlen = sizeof(h->peer);
-
- if (timeout != 0) {
- int ret;
- struct timeval tv;
- fd_set read_fds;
-
- if (timeout < 0) {
- /* non-block non-timeout */
- tv.tv_sec = 0;
- tv.tv_usec = 0;
- } else {
- tv.tv_sec = timeout / 1000000;
- tv.tv_usec = timeout % 1000000;
- }
-
- FD_ZERO(&read_fds);
- FD_SET(h->fd, &read_fds);
- ret = select(h->fd+1, &read_fds, NULL, NULL, &tv);
- if (ret < 0) {
- if (errno == EINTR) {
- printf("eintr\n");
- return 0;
- } else {
- lttctl_errno = LTTCTL_ERR_RECV;
- lttctl_perror("Netlink recvfrom");
- return -1;
- }
- }
- if (!FD_ISSET(h->fd, &read_fds)) {
- lttctl_errno = LTTCTL_ERR_TIMEOUT;
- printf("timeout\n");
- return 0;
- }
- }
- status = recvfrom(h->fd, buf, len, 0,
- (struct sockaddr *)&h->peer, &addrlen);
-
- if (status < 0) {
- lttctl_errno = LTTCTL_ERR_RECV;
- lttctl_perror("Netlink recvfrom");
- return status;
- }
- if (addrlen != sizeof(h->peer)) {
- lttctl_errno = LTTCTL_ERR_RECV;
- lttctl_perror("Netlink recvfrom");
- return -1;
- }
- if (h->peer.nl_pid != 0) {
- lttctl_errno = LTTCTL_ERR_RECV;
- lttctl_perror("Netlink recvfrom");
- return -1;
- }
- if (status == 0) {
- lttctl_errno = LTTCTL_ERR_NLEOF;
- lttctl_perror("Netlink recvfrom");
- return -1;
- }
- nlh = (struct nlmsghdr *)buf;
- if (nlh->nlmsg_flags & MSG_TRUNC || nlh->nlmsg_len > status) {
- lttctl_errno = LTTCTL_ERR_RTRUNC;
- lttctl_perror("Netlink recvfrom");
- return -1;
- }
-
-
- return status;
-}
-
-
-static char *lttctl_strerror(int errcode)
-{
- if (errcode < 0 || errcode > LTTCTL_MAXERR)
- errcode = LTTCTL_ERR_IMPL;
- return lttctl_errmap[errcode].message;
-}
-
-
-char *lttctl_errstr(void)
-{
- return lttctl_strerror(lttctl_errno);
-}
-
-void lttctl_perror(const char *s)
-{
- if (s)
- fputs(s, stderr);
- else
- fputs("ERROR", stderr);
- if (lttctl_errno)
- fprintf(stderr, ": %s", lttctl_errstr());
- if (errno)
- fprintf(stderr, ": %s", strerror(errno));
- fputc('\n', stderr);
-}
-
-/* public interface */
-
-/*
- * Create and initialise an lttctl handle.
- */
-struct lttctl_handle *lttctl_create_handle(void)
-{
- int status;
- struct lttctl_handle *h;
-
- h = (struct lttctl_handle *)malloc(sizeof(struct lttctl_handle));
- if (h == NULL) {
- lttctl_errno = LTTCTL_ERR_HANDLE;
- lttctl_perror("Create handle");
- goto alloc_error;
- }
-
- memset(h, 0, sizeof(struct lttctl_handle));
-
- h->fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_LTT);
-
- if (h->fd == -1) {
- lttctl_errno = LTTCTL_ERR_SOCKET;
- lttctl_perror("Create handle");
- goto socket_error;
- }
- memset(&h->local, 0, sizeof(struct sockaddr_nl));
- h->local.nl_family = AF_NETLINK;
- h->local.nl_pid = getpid();
- h->local.nl_groups = 0;
- status = bind(h->fd, (struct sockaddr *)&h->local, sizeof(h->local));
- if (status == -1) {
- lttctl_errno = LTTCTL_ERR_BIND;
- lttctl_perror("Create handle");
- goto bind_error;
- }
- memset(&h->peer, 0, sizeof(struct sockaddr_nl));
- h->peer.nl_family = AF_NETLINK;
- h->peer.nl_pid = 0;
- h->peer.nl_groups = 0;
- return h;
-
- /* Error condition */
-bind_error:
-socket_error:
- close(h->fd);
-alloc_error:
- free(h);
- return NULL;
-}
-
-/*
- * No error condition is checked here at this stage, but it may happen
- * if/when reliable messaging is implemented.
- */
-int lttctl_destroy_handle(struct lttctl_handle *h)
-{
- if (h) {
- close(h->fd);
- free(h);
- }
- return 0;
-}
-
-
-int lttctl_create_trace(const struct lttctl_handle *h,
- char *name, enum trace_mode mode, char *trace_type,
- unsigned subbuf_size_low, unsigned n_subbufs_low,
- unsigned subbuf_size_med, unsigned n_subbufs_med,
- unsigned subbuf_size_high, unsigned n_subbufs_high)
-{
- int err;
-
- struct {
- struct nlmsghdr nlh;
- lttctl_peer_msg_t msg;
- } req;
- struct {
- struct nlmsghdr nlh;
- struct nlmsgerr nlerr;
- lttctl_peer_msg_t msg;
- } ack;
-
- memset(&req, 0, sizeof(req));
- req.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(lttctl_peer_msg_t));
- req.nlh.nlmsg_flags = NLM_F_REQUEST|NLM_F_ACK;
- req.nlh.nlmsg_type = LTTCTLM_CONTROL;
- req.nlh.nlmsg_pid = h->local.nl_pid;
- req.nlh.nlmsg_seq = 0;
-
- strncpy(req.msg.trace_name, name, NAME_MAX);
- strncpy(req.msg.trace_type, trace_type, NAME_MAX);
- req.msg.op = OP_CREATE;
- req.msg.args.new_trace.mode = mode;
- req.msg.args.new_trace.subbuf_size_low = subbuf_size_low;
- req.msg.args.new_trace.n_subbufs_low = n_subbufs_low;
- req.msg.args.new_trace.subbuf_size_med = subbuf_size_med;
- req.msg.args.new_trace.n_subbufs_med = n_subbufs_med;
- req.msg.args.new_trace.subbuf_size_high = subbuf_size_high;
- req.msg.args.new_trace.n_subbufs_high = n_subbufs_high;
-
- err = lttctl_netlink_sendto(h, (void *)&req, req.nlh.nlmsg_len);
- if(err < 0) goto senderr;
-
- err = lttctl_netlink_recvfrom(h, (void*)&ack, sizeof(ack), 0);
- if(err < 0) goto senderr;
-
- err = ack.nlerr.error;
- if(err != 0) {
- errno = err;
- lttctl_perror("Create Trace Error");
- return err;
- }
-
- return 0;
-
-senderr:
- lttctl_perror("Create Trace Error");
- err = EPERM;
- return err;
-}
-
-int lttctl_destroy_trace(const struct lttctl_handle *h,
- char *name)
-{
- struct {
- struct nlmsghdr nlh;
- lttctl_peer_msg_t msg;
- } req;
- struct {
- struct nlmsghdr nlh;
- struct nlmsgerr nlerr;
- lttctl_peer_msg_t msg;
- } ack;
- int err;
-
- memset(&req, 0, sizeof(req));
- req.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(lttctl_peer_msg_t));
- req.nlh.nlmsg_flags = NLM_F_REQUEST;
- req.nlh.nlmsg_type = LTTCTLM_CONTROL;
- req.nlh.nlmsg_pid = h->local.nl_pid;
-
- strncpy(req.msg.trace_name, name, NAME_MAX);
- req.msg.op = OP_DESTROY;
-
- err = lttctl_netlink_sendto(h, (void *)&req, req.nlh.nlmsg_len);
- if(err < 0) goto senderr;
-
- err = lttctl_netlink_recvfrom(h, (void*)&ack, sizeof(ack), 0);
- if(err < 0) goto senderr;
-
- err = ack.nlerr.error;
- if(err != 0) {
- errno = err;
- lttctl_perror("Destroy Trace Channels Error");
- return err;
- }
-
- return 0;
-
-senderr:
- lttctl_perror("Destroy Trace Channels Error");
- err = EPERM;
- return err;
-
-}
-
-int lttctl_start(const struct lttctl_handle *h,
- char *name)
-{
- struct {
- struct nlmsghdr nlh;
- lttctl_peer_msg_t msg;
- } req;
- struct {
- struct nlmsghdr nlh;
- struct nlmsgerr nlerr;
- lttctl_peer_msg_t msg;
- } ack;
-
- int err;
-
- memset(&req, 0, sizeof(req));
- req.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(lttctl_peer_msg_t));
- req.nlh.nlmsg_flags = NLM_F_REQUEST;
- req.nlh.nlmsg_type = LTTCTLM_CONTROL;
- req.nlh.nlmsg_pid = h->local.nl_pid;
-
- strncpy(req.msg.trace_name, name, NAME_MAX);
- req.msg.op = OP_START;
-
- err = lttctl_netlink_sendto(h, (void *)&req, req.nlh.nlmsg_len);
- if(err < 0) goto senderr;
-
- err = lttctl_netlink_recvfrom(h, (void*)&ack, sizeof(ack), 0);
- if(err < 0) goto senderr;
-
- err = ack.nlerr.error;
- if(err != 0) {
- errno = err;
- lttctl_perror("Start Trace Error");
- return err;
- }
-
- return 0;
-
-senderr:
- err = EPERM;
- lttctl_perror("Start Trace Error");
- return err;
-
-}
-
-int lttctl_stop(const struct lttctl_handle *h,
- char *name)
-{
- struct {
- struct nlmsghdr nlh;
- lttctl_peer_msg_t msg;
- } req;
- struct {
- struct nlmsghdr nlh;
- struct nlmsgerr nlerr;
- lttctl_peer_msg_t msg;
- } ack;
- int err;
-
- memset(&req, 0, sizeof(req));
- req.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(lttctl_peer_msg_t));
- req.nlh.nlmsg_flags = NLM_F_REQUEST;
- req.nlh.nlmsg_type = LTTCTLM_CONTROL;
- req.nlh.nlmsg_pid = h->local.nl_pid;
-
- strncpy(req.msg.trace_name, name, NAME_MAX);
- req.msg.op = OP_STOP;
-
- err = lttctl_netlink_sendto(h, (void *)&req, req.nlh.nlmsg_len);
- if(err < 0) goto senderr;
-
- err = lttctl_netlink_recvfrom(h, (void*)&ack, sizeof(ack), 0);
- if(err < 0) goto senderr;
-
- err = ack.nlerr.error;
- if(err != 0) {
- errno = err;
- lttctl_perror("Stop Trace Error");
- return err;
- }
-
- return 0;
-
-senderr:
- err = EPERM;
- lttctl_perror("Stop Trace Error");
- return err;
-}
-
projects / ltt-control.git / blobdiff