qnx修改tcp和udp缓冲区默认大小

拷贝/home/test/qnx/qos223/target/qnx7/aarch64le/sbin/sysctl进系统中

https://www.qnx.com/developers/docs/7.1/#com.qnx.doc.neutrino.utilities/topic/s/sysctl.html

kern.sbmax 默认262144，这个限制住了发送、接收缓冲器大小

./sysctl -w kern.sbmax=1000000 #to 1M 必须先执行
./sysctl -w net.inet.udp.sendspace=233000
./sysctl -w net.inet.udp.recvspace=233000
./sysctl -w net.inet.tcp.sendspace=233000
./sysctl -w net.inet.tcp.sendspace=233000

另外，可直接修改/etc/inetd.conf

https://www.qnx.com/developers/docs/7.1/#com.qnx.doc.neutrino.utilities/topic/i/inetd.conf.html

测试c语言函数

/* getsndrcv.c:
 * getsockopt sample c code
 * using getsockopt
 * Get SO_SNDBUF & SO_RCVBUF Options:
 */
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
/*
 * This function reports the error and
 * exits back to the shell:
 */
static void displayError(const char *on_what) {
  if (errno != 0) {
    fputs(strerror(errno), stderr);
    fputs(": ", stderr);
  }
  fputs(on_what, stderr);
  fputc('\n', stderr);
  exit(1);
}
int main(int argc, char **argv) {
  int z;
  int s = -1;       /* Socket */
  int sndbuf = 0;   /* Send buffer size */
  int rcvbuf = 0;   /* Receive buffer size */
  socklen_t optlen; /* Option length */
  /*
   * Create a TDP/IP socket to use:
   */
  s = socket(PF_INET, SOCK_DGRAM, 0);
  /*s = socket(PF_INET,SOCK_DGRAM,0);  udp使用本行代码*/
  if (s == -1) {
    displayError("socket(2)");
  }
  /*
   * Get socket option SO_SNDBUF:
   */
  optlen = sizeof sndbuf;
  z = getsockopt(s, SOL_SOCKET, SO_SNDBUF, &sndbuf, &optlen);
  if (z) {
    displayError(
        "getsockopt(s,SOL_SOCKET,"
        "SO_SNDBUF)");
  }
  assert(optlen == sizeof sndbuf);
  /*
   * Get socket option SO_SNDBUF:
   */
  optlen = sizeof rcvbuf;
  z = getsockopt(s, SOL_SOCKET, SO_RCVBUF, &rcvbuf, &optlen);
  if (z) {
    displayError(
        "getsockopt(s,SOL_SOCKET,"
        "SO_RCVBUF)");
  }
  assert(optlen == sizeof rcvbuf);
  /*
   * Report the buffer sizes:
   */
  printf("Socket s : %d\n", s);
  printf("Send buf: %d bytes\n", sndbuf);
  printf("Recv buf: %d bytes\n", rcvbuf);
  close(s);
  return 0;
}
/*
 * OUTPUT
 *
 [sgupta@rhel54x64 socket]$ gcc getsndrcv.c -o getsndrcv -lsocket
 [sgupta@rhel54x64 socket]$ ./getsndrcv
 Socket s : 3
 Send buf: 16384 bytes
 Recv buf: 87380 bytes
 [sgupta@rhel54x64 socket]$
 */