blob: 295e78d156475ea4038469eafd09d1a471371d33 [file] [log] [blame]
/* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later */
#include "libpldm/transport.h"
#include "libpldm/base.h"
#include "libpldm/pldm.h"
#include "transport.h"
#include <errno.h>
#include <limits.h>
#ifdef PLDM_HAS_POLL
#include <poll.h>
#endif
#include <stdbool.h>
#include <stdlib.h>
#include <sys/time.h>
#include <time.h>
#include <unistd.h>
#ifndef PLDM_HAS_POLL
struct pollfd {
int fd; /* file descriptor */
short events; /* requested events */
short revents; /* returned events */
};
static inline int poll(struct pollfd *fds __attribute__((unused)),
int nfds __attribute__((unused)),
int timeout __attribute__((unused)))
{
return 0;
}
#endif
LIBPLDM_ABI_STABLE
int pldm_transport_poll(struct pldm_transport *transport, int timeout)
{
struct pollfd pollfd;
int rc = 0;
if (!transport) {
return PLDM_REQUESTER_INVALID_SETUP;
}
/* If polling isn't supported then always indicate the transport is ready */
if (!transport->init_pollfd) {
return 1;
}
rc = transport->init_pollfd(transport, &pollfd);
if (rc < 0) {
return PLDM_REQUESTER_POLL_FAIL;
}
rc = poll(&pollfd, 1, timeout);
if (rc < 0) {
return PLDM_REQUESTER_POLL_FAIL;
}
/* rc is 0 if poll(2) times out, or 1 if pollfd becomes active. */
return rc;
}
LIBPLDM_ABI_STABLE
pldm_requester_rc_t pldm_transport_send_msg(struct pldm_transport *transport,
pldm_tid_t tid,
const void *pldm_msg,
size_t msg_len)
{
if (!transport || !pldm_msg) {
return PLDM_REQUESTER_INVALID_SETUP;
}
if (msg_len < sizeof(struct pldm_msg_hdr)) {
return PLDM_REQUESTER_NOT_REQ_MSG;
}
return transport->send(transport, tid, pldm_msg, msg_len);
}
LIBPLDM_ABI_STABLE
pldm_requester_rc_t pldm_transport_recv_msg(struct pldm_transport *transport,
pldm_tid_t *tid, void **pldm_msg,
size_t *msg_len)
{
if (!transport || !msg_len) {
return PLDM_REQUESTER_INVALID_SETUP;
}
pldm_requester_rc_t rc =
transport->recv(transport, tid, pldm_msg, msg_len);
if (rc != PLDM_REQUESTER_SUCCESS) {
return rc;
}
if (*msg_len < sizeof(struct pldm_msg_hdr)) {
free(*pldm_msg);
*pldm_msg = NULL;
return PLDM_REQUESTER_INVALID_RECV_LEN;
}
return PLDM_REQUESTER_SUCCESS;
}
static void timespec_to_timeval(const struct timespec *ts, struct timeval *tv)
{
tv->tv_sec = ts->tv_sec;
tv->tv_usec = ts->tv_nsec / 1000;
}
/* Overflow safety must be upheld before call */
static long timeval_to_msec(const struct timeval *tv)
{
return tv->tv_sec * 1000 + tv->tv_usec / 1000;
}
/* If calculations on `tv` don't overflow then operations on derived
* intervals can't either.
*/
static bool timeval_is_valid(const struct timeval *tv)
{
if (tv->tv_sec < 0 || tv->tv_usec < 0 || tv->tv_usec >= 1000000) {
return false;
}
if (tv->tv_sec > (LONG_MAX - tv->tv_usec / 1000) / 1000) {
return false;
}
return true;
}
static int clock_gettimeval(clockid_t clockid, struct timeval *tv)
{
struct timespec now;
int rc;
rc = clock_gettime(clockid, &now);
if (rc < 0) {
return rc;
}
timespec_to_timeval(&now, tv);
return 0;
}
LIBPLDM_ABI_STABLE
pldm_requester_rc_t
pldm_transport_send_recv_msg(struct pldm_transport *transport, pldm_tid_t tid,
const void *pldm_req_msg, size_t req_msg_len,
void **pldm_resp_msg, size_t *resp_msg_len)
{
/**
* Section "Requirements for requesters" in DSP0240, define the Time-out
* waiting for a response of the requester.
* PT2max = PT3min - 2*PT4max = 4800ms
*/
static const struct timeval max_response_interval = {
.tv_sec = 4, .tv_usec = 800000
};
const struct pldm_msg_hdr *req_hdr;
struct timeval remaining;
pldm_requester_rc_t rc;
struct timeval now;
struct timeval end;
int ret;
int cnt;
if (req_msg_len < sizeof(*req_hdr) || !resp_msg_len) {
return PLDM_REQUESTER_INVALID_SETUP;
}
req_hdr = pldm_req_msg;
if (!req_hdr->request) {
return PLDM_REQUESTER_NOT_REQ_MSG;
}
for (cnt = 0; cnt <= (PLDM_INSTANCE_MAX + 1) * PLDM_MAX_TIDS &&
pldm_transport_poll(transport, 0) == 1;
cnt++) {
pldm_tid_t l_tid;
rc = pldm_transport_recv_msg(transport, &l_tid, pldm_resp_msg,
resp_msg_len);
if (rc == PLDM_REQUESTER_SUCCESS) {
/* This isn't the message we wanted */
free(*pldm_resp_msg);
}
}
if (cnt == (PLDM_INSTANCE_MAX + 1) * PLDM_MAX_TIDS) {
return PLDM_REQUESTER_TRANSPORT_BUSY;
}
rc = pldm_transport_send_msg(transport, tid, pldm_req_msg, req_msg_len);
if (rc != PLDM_REQUESTER_SUCCESS) {
return rc;
}
ret = clock_gettimeval(CLOCK_MONOTONIC, &now);
if (ret < 0) {
return PLDM_REQUESTER_POLL_FAIL;
}
timeradd(&now, &max_response_interval, &end);
if (!timeval_is_valid(&end)) {
return PLDM_REQUESTER_POLL_FAIL;
}
while (timercmp(&now, &end, <)) {
pldm_tid_t src_tid;
timersub(&end, &now, &remaining);
/* 0 <= `timeval_to_msec()` <= 4800, and 4800 < INT_MAX */
ret = pldm_transport_poll(transport,
(int)(timeval_to_msec(&remaining)));
if (ret <= 0) {
return PLDM_REQUESTER_RECV_FAIL;
}
ret = clock_gettimeval(CLOCK_MONOTONIC, &now);
if (ret < 0) {
return PLDM_REQUESTER_POLL_FAIL;
}
rc = pldm_transport_recv_msg(transport, &src_tid, pldm_resp_msg,
resp_msg_len);
if (rc != PLDM_REQUESTER_SUCCESS) {
continue;
}
if (src_tid != tid || !pldm_msg_hdr_correlate_response(
pldm_req_msg, *pldm_resp_msg)) {
free(*pldm_resp_msg);
continue;
}
return PLDM_REQUESTER_SUCCESS;
}
return PLDM_REQUESTER_RECV_FAIL;
}