wiznet与libmodbus软件包衔接对接SAL层传参问题

发布于 2020-12-28 13:50:13 浏览：2040 订阅该版

5 个回答

杰瑞鼠 2020-12-29

2024龙行天下

xiangxistu 2020-12-29

这家伙很懒，什么也没写！

可以看看这个参数的意义，不知道如何处理，建议看 lwip 中的实现；
```
#define SO_REUSEADDR   0x0004 /* Allow local address reuse */
```
这个就是导致错误的原因，wiznet 的 setsockopt 函数实现了常用的参数的解析处理，不过很遗憾没有实现对这个参数的解析；

在下面的代码中，也可以留意到 lwip 中并不是每一个参数都会完完整整的解析，所以说这个问题的解决有两个方案：

1. 修改 wiznet 中的代码，添加上这个参数的处理。
2. 修改 libmodbus 中代码，去掉 TCP 的这个传输特性。

如果楼主顺利解决了问题，可以向 package 仓库提交代码，方便更多的人使用。

```
int
lwip_setsockopt(int s, int level, int optname, const void *optval, socklen_t optlen)
{
  struct lwip_sock *sock = get_socket(s);
  err_t err = ERR_OK;
  struct lwip_setgetsockopt_data data;

if (!sock) {
    return -1;
  }

if (NULL == optval) {
    sock_set_errno(sock, EFAULT);
    return -1;
  }

/* Do length and type checks for the various options first, to keep it readable. */
  switch (level) {

/* Level: SOL_SOCKET */
  case SOL_SOCKET:
    switch (optname) {

case SO_BROADCAST:
    /* UNIMPL case SO_DEBUG: */
    /* UNIMPL case SO_DONTROUTE: */
    case SO_KEEPALIVE:
    /* UNIMPL case case SO_CONTIMEO: */
#if LWIP_SO_SNDTIMEO
    case SO_SNDTIMEO:
#endif /* LWIP_SO_SNDTIMEO */
#if LWIP_SO_RCVTIMEO
    case SO_RCVTIMEO:
#endif /* LWIP_SO_RCVTIMEO */
#if LWIP_SO_RCVBUF
    case SO_RCVBUF:
#endif /* LWIP_SO_RCVBUF */
    /* UNIMPL case SO_OOBINLINE: */
    /* UNIMPL case SO_SNDBUF: */
    /* UNIMPL case SO_RCVLOWAT: */
    /* UNIMPL case SO_SNDLOWAT: */
#if SO_REUSE
    case SO_REUSEADDR:
    case SO_REUSEPORT:
#endif /* SO_REUSE */
    /* UNIMPL case SO_USELOOPBACK: */
      if (optlen < sizeof(int)) {
        err = EINVAL;
      }
      break;
    case SO_NO_CHECK:
      if (optlen < sizeof(int)) {
        err = EINVAL;
      }
#if LWIP_UDP
      if ((sock->conn->type != NETCONN_UDP) ||
          ((udp_flags(sock->conn->pcb.udp) & UDP_FLAGS_UDPLITE) != 0)) {
        /* this flag is only available for UDP, not for UDP lite */
        err = EAFNOSUPPORT;
      }
#endif /* LWIP_UDP */
      break;
    default:
      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, SOL_SOCKET, UNIMPL: optname=0x%x, ..)\n",
                  s, optname));
      err = ENOPROTOOPT;
    }  /* switch (optname) */
    break;

/* Level: IPPROTO_IP */
  case IPPROTO_IP:
    switch (optname) {
    /* UNIMPL case IP_HDRINCL: */
    /* UNIMPL case IP_RCVDSTADDR: */
    /* UNIMPL case IP_RCVIF: */
    case IP_TTL:
    case IP_TOS:
      if (optlen < sizeof(int)) {
        err = EINVAL;
      }
      break;
#if LWIP_IGMP
    case IP_MULTICAST_TTL:
      if (optlen < sizeof(u8_t)) {
        err = EINVAL;
      }
      if (NETCONNTYPE_GROUP(sock->conn->type) != NETCONN_UDP) {
        err = EAFNOSUPPORT;
      }
      break;
    case IP_MULTICAST_IF:
      if (optlen < sizeof(struct in_addr)) {
        err = EINVAL;
      }
      if (NETCONNTYPE_GROUP(sock->conn->type) != NETCONN_UDP) {
        err = EAFNOSUPPORT;
      }
      break;
    case IP_MULTICAST_LOOP:
      if (optlen < sizeof(u8_t)) {
        err = EINVAL;
      }
      if (NETCONNTYPE_GROUP(sock->conn->type) != NETCONN_UDP) {
        err = EAFNOSUPPORT;
      }
      break;
    case IP_ADD_MEMBERSHIP:
    case IP_DROP_MEMBERSHIP:
      if (optlen < sizeof(struct ip_mreq)) {
        err = EINVAL;
      }
      if (NETCONNTYPE_GROUP(sock->conn->type) != NETCONN_UDP) {
        err = EAFNOSUPPORT;
      }
      break;
#endif /* LWIP_IGMP */
      default:
        LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_IP, UNIMPL: optname=0x%x, ..)\n",
                    s, optname));
        err = ENOPROTOOPT;
    }  /* switch (optname) */
    break;

#if LWIP_TCP
/* Level: IPPROTO_TCP */
  case IPPROTO_TCP:
    if (optlen < sizeof(int)) {
      err = EINVAL;
      break;
    }

/* If this is no TCP socket, ignore any options. */
    if (sock->conn->type != NETCONN_TCP)
      return 0;

switch (optname) {
    case TCP_NODELAY:
    case TCP_KEEPALIVE:
#if LWIP_TCP_KEEPALIVE
    case TCP_KEEPIDLE:
    case TCP_KEEPINTVL:
    case TCP_KEEPCNT:
#endif /* LWIP_TCP_KEEPALIVE */
      break;

default:
      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_TCP, UNIMPL: optname=0x%x, ..)\n",
                  s, optname));
      err = ENOPROTOOPT;
    }  /* switch (optname) */
    break;
#endif /* LWIP_TCP */
#if LWIP_UDP && LWIP_UDPLITE
/* Level: IPPROTO_UDPLITE */
  case IPPROTO_UDPLITE:
    if (optlen < sizeof(int)) {
      err = EINVAL;
      break;
    }

/* If this is no UDP lite socket, ignore any options. */
    if (sock->conn->type != NETCONN_UDPLITE)
      return 0;

switch (optname) {
    case UDPLITE_SEND_CSCOV:
    case UDPLITE_RECV_CSCOV:
      break;

default:
      LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, IPPROTO_UDPLITE, UNIMPL: optname=0x%x, ..)\n",
                  s, optname));
      err = ENOPROTOOPT;
    }  /* switch (optname) */
    break;
#endif /* LWIP_UDP && LWIP_UDPLITE */
/* UNDEFINED LEVEL */
  default:
    LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_setsockopt(%d, level=0x%x, UNIMPL: optname=0x%x, ..)\n",
                s, level, optname));
    err = ENOPROTOOPT;
  }  /* switch (level) */

if (err != ERR_OK) {
    sock_set_errno(sock, err);
    return -1;
  }

/* Now do the actual option processing */
  data.sock = sock;
#ifdef LWIP_DEBUG
  data.s = s;
#endif /* LWIP_DEBUG */
  data.level = level;
  data.optname = optname;
  data.optval = (void*)optval;
  data.optlen = &optlen;
  data.err = err;
  tcpip_callback(lwip_setsockopt_internal, &data);
  sys_arch_sem_wait(&sock->conn->op_completed, 0);
  /* maybe lwip_setsockopt_internal has changed err */
  err = data.err;

sock_set_errno(sock, err);
  return err ? -1 : 0;
}
```