path: root/samples/server.c

/*
 * Sample server to be tested with samples/client.c
 *
 * Copyright (c) 2020, Nutanix Inc. All rights reserved.
 *     Author: Thanos Makatos <thanos@nutanix.com>
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *      * Redistributions of source code must retain the above copyright
 *        notice, this list of conditions and the following disclaimer.
 *      * Redistributions in binary form must reproduce the above copyright
 *        notice, this list of conditions and the following disclaimer in the
 *        documentation and/or other materials provided with the distribution.
 *      * Neither the name of Nutanix nor the names of its contributors may be
 *        used to endorse or promote products derived from this software without
 *        specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
 *  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 *  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 *  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 *  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 *  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 *  DAMAGE.
 *
 */

#include <stdio.h>
#include <err.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <errno.h>
#include <time.h>
#include <assert.h>
#include <openssl/md5.h>

#include "../lib/muser.h"

struct dma_regions {
    uint64_t addr;
    uint64_t len;
};

#define NR_DMA_REGIONS  96

struct server_data {
    time_t bar0;
    uint8_t *bar1;
    struct dma_regions regions[NR_DMA_REGIONS];
};

static void
_log(void *pvt, lm_log_lvl_t lvl __attribute__((unused)), char const *msg)
{
    fprintf(stderr, "server: %s\n", msg);
}

/* returns time in seconds since Epoch */
ssize_t
bar0_access(void *pvt, char * const buf, size_t count, loff_t offset,
            const bool is_write)
{
    struct server_data *server_data = pvt;

    if (count != sizeof(time_t) || offset != 0) {
        errno = EINVAL;
        return -1;
    }

    if (is_write) {
        memcpy(&server_data->bar0, buf, count);
    } else {
        time_t delta = time(NULL) - server_data->bar0;
        memcpy(buf, &delta, count);
    }

    return count;
}

ssize_t
bar1_access(void *pvt, char * const buf, size_t count, loff_t offset,
            const bool is_write)
{
    assert(false);
}

bool irq_triggered = false;
static void _sa_handler(int signum)
{
    int _errno = errno;
    if (signum == SIGUSR1) {
        irq_triggered = true;
    }
    errno = _errno;
}

static void map_dma(void *pvt, uint64_t iova, uint64_t len)
{
    struct server_data *server_data = pvt;
    int idx;

    for (idx = 0; idx < NR_DMA_REGIONS; idx++) {
        if (server_data->regions[idx].addr == 0 &&
            server_data->regions[idx].len == 0)
            break;
    }
    if (idx >= NR_DMA_REGIONS) {
        fprintf(stderr, "Failed to add dma region, slots full\n");
        return;
    }

    server_data->regions[idx].addr = iova;
    server_data->regions[idx].len = len;
}

static int unmap_dma(void *pvt, uint64_t iova)
{
    struct server_data *server_data = pvt;
    int idx;

    for (idx = 0; idx < NR_DMA_REGIONS; idx++) {
        if (server_data->regions[idx].addr == iova) {
            server_data->regions[idx].addr = 0;
            server_data->regions[idx].len = 0;
            return 0;
        }
    }

    return -EINVAL;
}

void get_md5sum(char *buf, int len, char *md5sum)
{
	MD5_CTX ctx;

    MD5_Init(&ctx);
    MD5_Update(&ctx, buf, len);
    MD5_Final(md5sum, &ctx);

    return;
}

static int do_dma_io(lm_ctx_t *lm_ctx, struct server_data *server_data)
{
    int count = 4096;
    char buf[count], md5sum1[MD5_DIGEST_LENGTH], md5sum2[MD5_DIGEST_LENGTH];
    int i, ret;

    memset(buf, 'A', count);
    get_md5sum(buf, count, md5sum1);
    printf("%s: WRITE addr %#lx count %llu\n", __func__,
           server_data->regions[0].addr, count);
    ret = lm_dma_write(lm_ctx, server_data->regions[0].addr, count, buf);
    if (ret < 0) {
        fprintf(stderr, "lm_dma_write failed: %s\n", strerror(-ret));
        return ret;
    }

    memset(buf, 0, count);
    printf("%s: READ  addr %#lx count %llu\n", __func__,
	   server_data->regions[0].addr, count);
    ret = lm_dma_read(lm_ctx, server_data->regions[0].addr, count, buf);
    if (ret < 0) {
        fprintf(stderr, "lm_dma_read failed: %s\n", strerror(-ret));
        return ret;
    }
    get_md5sum(buf, count, md5sum2);
    for(i = 0; i < MD5_DIGEST_LENGTH; i++) {
        if (md5sum2[i] != md5sum1[i]) {
            fprintf(stderr, "DMA write and DMA read mismatch\n");
            return -EIO;
        }
    }

    return 0;
}

unsigned long map_area(void *pvt, unsigned long off, unsigned long len)
{
    assert(false);
}

int main(int argc, char *argv[])
{
    int ret;
    bool trans_sock = false, verbose = false;
    char opt;
    struct sigaction act = {.sa_handler = _sa_handler};
    struct server_data server_data = {0};
    int nr_sparse_areas = 2, size = 1024, i;
    struct lm_sparse_mmap_areas *sparse_areas;

    lm_ctx_t *lm_ctx;

    while ((opt = getopt(argc, argv, "v")) != -1) {
        switch (opt) {
            case 'v':
                verbose = true;
                break;
            default: /* '?' */
                err(EXIT_FAILURE, "Usage: %s [-d] <IOMMU group>\n", argv[0]);
        }
    }

    if (optind >= argc) {
        err(EXIT_FAILURE, "missing MUSER device UUID");
    }

    server_data.bar1 = malloc(sysconf(_SC_PAGESIZE));
    if (server_data.bar1 == NULL) {
        err(EXIT_FAILURE, "BAR1");
    }

    sparse_areas = calloc(1, sizeof(*sparse_areas) +
			  (nr_sparse_areas * sizeof(struct lm_mmap_area)));
    if (sparse_areas == NULL) {
        err(EXIT_FAILURE, "MMAP sparse areas ENOMEM");
        goto out;
    }
    sparse_areas->nr_mmap_areas = nr_sparse_areas;
    for (i = 0; i < nr_sparse_areas; i++) {
        sparse_areas->areas[i].start += size;
        sparse_areas->areas[i].size = size;
    }

    lm_dev_info_t dev_info = {
        .trans = LM_TRANS_SOCK,
        .log = verbose ? _log : NULL,
        .log_lvl = LM_DBG,
        .pci_info = {
            .reg_info[LM_DEV_BAR0_REG_IDX] = {
                .flags = LM_REG_FLAG_RW,
                .size = sizeof(time_t),
                .fn = &bar0_access
            },
            .reg_info[LM_DEV_BAR1_REG_IDX] = {
                .flags = LM_REG_FLAG_RW,
                .size = sysconf(_SC_PAGESIZE),
                .fn = &bar1_access,
                .mmap_areas = sparse_areas,
		        .map = map_area
            },
            .irq_count[LM_DEV_INTX_IRQ_IDX] = 1,
        },
        .uuid = argv[optind],
        .map_dma = map_dma,
        .unmap_dma = unmap_dma,
        .pvt = &server_data
    };

    sigemptyset(&act.sa_mask);
    if (sigaction(SIGUSR1, &act, NULL) == -1) {
        err(EXIT_FAILURE, "warning: failed to register signal handler: %m\n");
    }

    lm_ctx = lm_ctx_create(&dev_info);
    if (lm_ctx == NULL) {
        if (errno == EINTR) {
            goto out;
        }
        err(EXIT_FAILURE, "failed to initialize device emulation: %m\n");
    }

    do {
        ret = lm_ctx_drive(lm_ctx);
        if (ret == -EINTR) {
            if (irq_triggered) {
                irq_triggered = false;
                lm_irq_trigger(lm_ctx, 0);

                ret = do_dma_io(lm_ctx, &server_data);
                if (ret < 0) {
                    fprintf(stderr, "DMA read/write failed: %m\n");
                }
                ret = 0;
            }
        }
    } while (ret == 0);
    if (ret != -ENOTCONN && ret != -EINTR) {
        fprintf(stderr, "failed to realize device emulation: %m\n");
    }
out:
    lm_ctx_destroy(lm_ctx);
    free(server_data.bar1);
    free(sparse_areas);
    return ret;
}

/* ex: set tabstop=4 shiftwidth=4 softtabstop=4 expandtab: */