s2n-tls-sys 0.3.42

/*
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file is distributed
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */

/* On Windows, s2n-tls does not provide built-in socket I/O.
 * This file compiles to an empty translation unit on Windows.
 */
#ifndef _WIN32

    #include "utils/s2n_socket.h"

    #include <netinet/in.h>
    #include <netinet/tcp.h>
    #include <sys/socket.h>
    #include <unistd.h>

    #include "tls/s2n_connection.h"
    #include "utils/s2n_safety.h"

    #if TCP_CORK
        #define S2N_CORK     TCP_CORK
        #define S2N_CORK_ON  1
        #define S2N_CORK_OFF 0
    #elif TCP_NOPUSH
        #define S2N_CORK     TCP_NOPUSH
        #define S2N_CORK_ON  1
        #define S2N_CORK_OFF 0
    #elif TCP_NODELAY
        #define S2N_CORK     TCP_NODELAY
        #define S2N_CORK_ON  0
        #define S2N_CORK_OFF 1
    #endif

int s2n_socket_quickack(struct s2n_connection *conn)
{
    #ifdef TCP_QUICKACK
    POSIX_ENSURE_REF(conn);
    if (!conn->managed_recv_io) {
        return 0;
    }

    struct s2n_socket_read_io_context *r_io_ctx = (struct s2n_socket_read_io_context *) conn->recv_io_context;
    POSIX_ENSURE_REF(r_io_ctx);
    if (r_io_ctx->tcp_quickack_set) {
        return 0;
    }

    /* Ignore the return value, if it fails it fails */
    int optval = 1;
    if (setsockopt(r_io_ctx->fd, IPPROTO_TCP, TCP_QUICKACK, &optval, sizeof(optval)) == 0) {
        r_io_ctx->tcp_quickack_set = 1;
    }
    #endif

    return 0;
}

int s2n_socket_write_snapshot(struct s2n_connection *conn)
{
    #ifdef S2N_CORK
    socklen_t corklen = sizeof(int);
    POSIX_ENSURE_REF(conn);
    struct s2n_socket_write_io_context *w_io_ctx = (struct s2n_socket_write_io_context *) conn->send_io_context;
    POSIX_ENSURE_REF(w_io_ctx);

    getsockopt(w_io_ctx->fd, IPPROTO_TCP, S2N_CORK, &w_io_ctx->original_cork_val, &corklen);
    POSIX_ENSURE_EQ(corklen, sizeof(int));
    w_io_ctx->original_cork_is_set = 1;
    #endif

    return 0;
}

int s2n_socket_read_snapshot(struct s2n_connection *conn)
{
    #ifdef SO_RCVLOWAT
    socklen_t watlen = sizeof(int);
    POSIX_ENSURE_REF(conn);
    struct s2n_socket_read_io_context *r_io_ctx = (struct s2n_socket_read_io_context *) conn->recv_io_context;
    POSIX_ENSURE_REF(r_io_ctx);

    getsockopt(r_io_ctx->fd, SOL_SOCKET, SO_RCVLOWAT, &r_io_ctx->original_rcvlowat_val, &watlen);
    POSIX_ENSURE_EQ(watlen, sizeof(int));
    r_io_ctx->original_rcvlowat_is_set = 1;
    #endif

    return 0;
}

int s2n_socket_write_restore(struct s2n_connection *conn)
{
    #ifdef S2N_CORK
    POSIX_ENSURE_REF(conn);
    struct s2n_socket_write_io_context *w_io_ctx = (struct s2n_socket_write_io_context *) conn->send_io_context;
    POSIX_ENSURE_REF(w_io_ctx);

    if (!w_io_ctx->original_cork_is_set) {
        return 0;
    }
    setsockopt(w_io_ctx->fd, IPPROTO_TCP, S2N_CORK, &w_io_ctx->original_cork_val, sizeof(w_io_ctx->original_cork_val));
    w_io_ctx->original_cork_is_set = 0;
    #endif

    return 0;
}

int s2n_socket_read_restore(struct s2n_connection *conn)
{
    #ifdef SO_RCVLOWAT
    POSIX_ENSURE_REF(conn);
    struct s2n_socket_read_io_context *r_io_ctx = (struct s2n_socket_read_io_context *) conn->recv_io_context;
    POSIX_ENSURE_REF(r_io_ctx);

    if (!r_io_ctx->original_rcvlowat_is_set) {
        return 0;
    }
    setsockopt(r_io_ctx->fd, SOL_SOCKET, SO_RCVLOWAT, &r_io_ctx->original_rcvlowat_val, sizeof(r_io_ctx->original_rcvlowat_val));
    r_io_ctx->original_rcvlowat_is_set = 0;
    #endif

    return 0;
}

int s2n_socket_was_corked(struct s2n_connection *conn)
{
    POSIX_ENSURE_REF(conn);
    /* If we're not using custom I/O and a send fd has not been set yet, return false*/
    if (!conn->managed_send_io || !conn->send) {
        return 0;
    }

    struct s2n_socket_write_io_context *io_ctx = (struct s2n_socket_write_io_context *) conn->send_io_context;
    POSIX_ENSURE_REF(io_ctx);

    return io_ctx->original_cork_val;
}

int s2n_socket_write_cork(struct s2n_connection *conn)
{
    #ifdef S2N_CORK
    POSIX_ENSURE_REF(conn);
    int optval = S2N_CORK_ON;

    struct s2n_socket_write_io_context *w_io_ctx = (struct s2n_socket_write_io_context *) conn->send_io_context;
    POSIX_ENSURE_REF(w_io_ctx);

    /* Ignore the return value, if it fails it fails */
    setsockopt(w_io_ctx->fd, IPPROTO_TCP, S2N_CORK, &optval, sizeof(optval));
    #endif

    return 0;
}

int s2n_socket_write_uncork(struct s2n_connection *conn)
{
    #ifdef S2N_CORK
    POSIX_ENSURE_REF(conn);
    int optval = S2N_CORK_OFF;

    struct s2n_socket_write_io_context *w_io_ctx = (struct s2n_socket_write_io_context *) conn->send_io_context;
    POSIX_ENSURE_REF(w_io_ctx);

    /* Ignore the return value, if it fails it fails */
    setsockopt(w_io_ctx->fd, IPPROTO_TCP, S2N_CORK, &optval, sizeof(optval));
    #endif

    return 0;
}

int s2n_socket_read(void *io_context, uint8_t *buf, uint32_t len)
{
    POSIX_ENSURE_REF(io_context);
    POSIX_ENSURE_REF(buf);
    int rfd = ((struct s2n_socket_read_io_context *) io_context)->fd;
    if (rfd < 0) {
        errno = EBADF;
        POSIX_BAIL(S2N_ERR_BAD_FD);
    }

    /* Clear the quickack flag so we know to reset it */
    ((struct s2n_socket_read_io_context *) io_context)->tcp_quickack_set = 0;

    /* On success, the number of bytes read is returned. On failure, -1 is
     * returned and errno is set appropriately. */
    ssize_t result = read(rfd, buf, len);
    POSIX_ENSURE_INCLUSIVE_RANGE(INT_MIN, result, INT_MAX);
    return result;
}

int s2n_socket_write(void *io_context, const uint8_t *buf, uint32_t len)
{
    POSIX_ENSURE_REF(io_context);
    POSIX_ENSURE_REF(buf);
    int wfd = ((struct s2n_socket_write_io_context *) io_context)->fd;
    if (wfd < 0) {
        errno = EBADF;
        POSIX_BAIL(S2N_ERR_BAD_FD);
    }

    /* On success, the number of bytes written is returned. On failure, -1 is
     * returned and errno is set appropriately. */
    ssize_t result = write(wfd, buf, len);
    POSIX_ENSURE_INCLUSIVE_RANGE(INT_MIN, result, INT_MAX);
    return result;
}

#endif

/* Suppress empty translation unit warning when compiled on Windows. */
#pragma clang diagnostic ignored "-Wempty-translation-unit"