lwip_raw_common_impl.cpp

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#include "lwip_raw_common_impl.h"
#include "esphome/core/defines.h"
 
#ifdef USE_SOCKET_IMPL_LWIP_TCP
 
#include <cerrno>
#include <cstring>
 
namespace esphome::socket {
 
int lwip_ip_to_sockaddr(sa_family_t family, const ip_addr_t *ip, uint16_t port_host, struct sockaddr *name,
                        socklen_t *addrlen) {
  if (family == AF_INET) {
    if (*addrlen < sizeof(struct sockaddr_in)) {
      errno = EINVAL;
      return -1;
    }
    auto *addr = reinterpret_cast<struct sockaddr_in *>(name);
    addr->sin_family = AF_INET;
    *addrlen = addr->sin_len = sizeof(struct sockaddr_in);
    addr->sin_port = htons(port_host);
    inet_addr_from_ip4addr(&addr->sin_addr, ip_2_ip4(ip));
    return 0;
  }
#if LWIP_IPV6
  if (family == AF_INET6) {
    if (*addrlen < sizeof(struct sockaddr_in6)) {
      errno = EINVAL;
      return -1;
    }
    auto *addr = reinterpret_cast<struct sockaddr_in6 *>(name);
    addr->sin6_family = AF_INET6;
    *addrlen = addr->sin6_len = sizeof(struct sockaddr_in6);
    addr->sin6_port = htons(port_host);
    // AF_INET6 sockets may receive IPv4 packets; convert to IPv4-mapped IPv6.
    if (IP_IS_V4(ip)) {
      ip_addr_t mapped;
      ip4_2_ipv4_mapped_ipv6(ip_2_ip6(&mapped), ip_2_ip4(ip));
      inet6_addr_from_ip6addr(&addr->sin6_addr, ip_2_ip6(&mapped));
    } else {
      inet6_addr_from_ip6addr(&addr->sin6_addr, ip_2_ip6(ip));
    }
    return 0;
  }
#endif
  errno = EAFNOSUPPORT;
  return -1;
}
 
bool sockaddr_to_lwip(const struct sockaddr *addr, socklen_t addrlen, ip_addr_t *ip, uint16_t *port) {
  // headers.h defines sockaddr and sockaddr_in with the same size, so this covers AF_INET
  if (addrlen < sizeof(struct sockaddr))
    return false;
  // Zero the whole struct — the IPv6 zone byte would otherwise be stack garbage
  memset(ip, 0, sizeof(*ip));
  if (addr->sa_family == AF_INET) {
    auto *addr4 = reinterpret_cast<const sockaddr_in *>(addr);
    *port = ntohs(addr4->sin_port);
    IP_SET_TYPE_VAL(*ip, IPADDR_TYPE_V4);
    ip_2_ip4(ip)->addr = addr4->sin_addr.s_addr;
    return true;
  }
#if LWIP_IPV6
  if (addr->sa_family == AF_INET6) {
    if (addrlen < sizeof(sockaddr_in6))
      return false;
    auto *addr6 = reinterpret_cast<const sockaddr_in6 *>(addr);
    *port = ntohs(addr6->sin6_port);
    IP_SET_TYPE_VAL(*ip, IPADDR_TYPE_V6);
    memcpy(&ip_2_ip6(ip)->addr, &addr6->sin6_addr.un.u8_addr, 16);
    // Unmap ::ffff:a.b.c.d so replies to recvfrom addresses route as IPv4
    if (ip6_addr_isipv4mappedipv6(ip_2_ip6(ip))) {
      unmap_ipv4_mapped_ipv6(ip_2_ip4(ip), ip_2_ip6(ip));
      IP_SET_TYPE_VAL(*ip, IPADDR_TYPE_V4);
    }
    return true;
  }
#endif
  return false;
}
 
bool sockaddr_to_lwip_bind(sa_family_t family, const struct sockaddr *addr, socklen_t addrlen, ip_addr_t *ip,
                           uint16_t *port) {
  const bool ok = sockaddr_to_lwip(addr, addrlen, ip, port);
#if LWIP_IPV6
  // Only promote wildcard binds — a specific address must keep filtering
  if (ok && family == AF_INET6 && ip_addr_isany_val(*ip))
    IP_SET_TYPE_VAL(*ip, IPADDR_TYPE_ANY);
#endif
  return ok;
}
 
int lwip_err_to_errno(err_t err) {
  switch (err) {
    case ERR_MEM:
      return ENOMEM;
    case ERR_BUF:
      return EAGAIN;  // transient, e.g. no free local port
    case ERR_RTE:
      return EHOSTUNREACH;  // no route, e.g. no address yet
    case ERR_VAL:
    case ERR_ARG:
      return EINVAL;
    case ERR_USE:
      return EADDRINUSE;
    case ERR_ISCONN:
      return EISCONN;
    default:
      return EIO;
  }
}
 
}  // namespace esphome::socket
 
#endif  // USE_SOCKET_IMPL_LWIP_TCP