rte_posix_osadapter_sockbuf.c

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/* _POSIX_C_SOURCE: the same feature-test macro as every other file of this product (it builds strict C99); glibc
 * declares socklen_t, setsockopt() and getsockopt() in <sys/socket.h> under it as well. */
#define _POSIX_C_SOURCE 200809L

#include "rte_posix_osadapter_sockbuf.h"
 
#include <limits.h>
#include <stdbool.h>
#include <stdint.h>
#include <sys/socket.h>
 
#include "rte_posix_osadapter_report.h"

#if defined(__linux__)
#define POSIX_SOCKBUF_READBACK_FACTOR 2
#else
#define POSIX_SOCKBUF_READBACK_FACTOR 1
#endif


static rte_status_t apply_one(int fd, int option, uint32_t bytes, bool *capped);




static rte_status_t apply_one(int fd, int option, uint32_t bytes, bool *capped)
{
    rte_status_t status = RTE_STATUS_OK;
 
    if (bytes != 0U)
    {
        const int requested = (bytes > (uint32_t)INT_MAX) ? INT_MAX : (int)bytes;
        int confirmed = 0;
        socklen_t length = (socklen_t)sizeof(confirmed);
 
        status = RTE_STATUS_INTERNAL_ERROR;
        if (setsockopt(fd, SOL_SOCKET, option, &requested, (socklen_t)sizeof(requested)) == 0)
        {
            if (getsockopt(fd, SOL_SOCKET, option, &confirmed, &length) == 0)
            {
                if (length == (socklen_t)sizeof(confirmed))
                {
                    const int64_t expected = (int64_t)requested * (int64_t)POSIX_SOCKBUF_READBACK_FACTOR;
 
                    if ((int64_t)confirmed < expected)
                    {
                        *capped = true;
                    }
                    status = RTE_STATUS_OK;
                }
            }
        }
    }
    return status;
}

 
rte_status_t posix_socket_apply_buffers(int fd, const rte_netlink_config_t *config)
{
    rte_status_t status = RTE_STATUS_INVALID_PARAM;
    bool capped = false;
 
    if (config != NULL)
    {
        status = apply_one(fd, SO_RCVBUF, config->rcvbuf_bytes, &capped);
        if (status == RTE_STATUS_OK)
        {
            status = apply_one(fd, SO_SNDBUF, config->sndbuf_bytes, &capped);
        }
        if ((status == RTE_STATUS_OK) && capped)
        {
            /* OSA rules R5/R6: the OS kept a smaller buffer than configured (Linux caps at net.core.rmem_max /
             * wmem_max without an error). Reported once per socket; the link is kept (REQ-OAL-NETLINK-015). */
            POSIX_OSA_REPORT_RT_ATTRIBUTE("socket buffer size capped");
        }
    }
    return status;
}