mscclpp/src/bootstrap/socket.cc

/*************************************************************************
 * Copyright (c) 2016-2022, NVIDIA CORPORATION. All rights reserved.
 *
 * See LICENSE.txt for license information
 ************************************************************************/

#include "socket.h"
#include "config.h"
#include "utils.h"

#include <stdlib.h>

#include <ifaddrs.h>
#include <net/if.h>
#include <unistd.h>

static mscclppResult_t socketProgressOpt(int op, struct mscclppSocket* sock, void* ptr, int size, int* offset,
                                         int block, int* closed)
{
  int bytes = 0;
  *closed = 0;
  char* data = (char*)ptr;
  char line[SOCKET_NAME_MAXLEN + 1];
  do {
    if (op == MSCCLPP_SOCKET_RECV)
      bytes = recv(sock->fd, data + (*offset), size - (*offset), block ? 0 : MSG_DONTWAIT);
    if (op == MSCCLPP_SOCKET_SEND)
      bytes = send(sock->fd, data + (*offset), size - (*offset), block ? MSG_NOSIGNAL : MSG_DONTWAIT | MSG_NOSIGNAL);
    if (op == MSCCLPP_SOCKET_RECV && bytes == 0) {
      *closed = 1;
      return mscclppSuccess;
    }
    if (bytes == -1) {
      if (errno != EINTR && errno != EWOULDBLOCK && errno != EAGAIN) {
        WARN("socketProgressOpt: Call to recv from %s failed : %s", mscclppSocketToString(&sock->addr, line),
             strerror(errno));
        return mscclppRemoteError;
      } else {
        bytes = 0;
      }
    }
    (*offset) += bytes;
    if (sock->abortFlag && *sock->abortFlag != 0) {
      INFO(MSCCLPP_NET, "socketProgressOpt: abort called");
      return mscclppInternalError;
    }
  } while (bytes > 0 && (*offset) < size);
  return mscclppSuccess;
}

static mscclppResult_t socketProgress(int op, struct mscclppSocket* sock, void* ptr, int size, int* offset)
{
  int closed;
  MSCCLPPCHECK(socketProgressOpt(op, sock, ptr, size, offset, 0, &closed));
  if (closed) {
    char line[SOCKET_NAME_MAXLEN + 1];
    WARN("socketProgress: Connection closed by remote peer %s", mscclppSocketToString(&sock->addr, line, 0));
    return mscclppRemoteError;
  }
  return mscclppSuccess;
}

static mscclppResult_t socketWait(int op, struct mscclppSocket* sock, void* ptr, int size, int* offset)
{
  while (*offset < size)
    MSCCLPPCHECK(socketProgress(op, sock, ptr, size, offset));
  return mscclppSuccess;
}

/* Format a string representation of a (union mscclppSocketAddress *) socket address using getnameinfo()
 *
 * Output: "IPv4/IPv6 address<port>"
 */
const char* mscclppSocketToString(union mscclppSocketAddress* addr, char* buf, const int numericHostForm /*= 1*/)
{
  if (buf == NULL || addr == NULL)
    return NULL;
  struct sockaddr* saddr = &addr->sa;
  if (saddr->sa_family != AF_INET && saddr->sa_family != AF_INET6) {
    buf[0] = '\0';
    return buf;
  }
  char host[NI_MAXHOST], service[NI_MAXSERV];
  /* NI_NUMERICHOST: If set, then the numeric form of the hostname is returned.
   * (When not set, this will still happen in case the node's name cannot be determined.)
   */
  int flag = NI_NUMERICSERV | (numericHostForm ? NI_NUMERICHOST : 0);
  (void)getnameinfo(saddr, sizeof(union mscclppSocketAddress), host, NI_MAXHOST, service, NI_MAXSERV, flag);
  sprintf(buf, "%s<%s>", host, service);
  return buf;
}

static uint16_t socketToPort(union mscclppSocketAddress* addr)
{
  struct sockaddr* saddr = &addr->sa;
  return ntohs(saddr->sa_family == AF_INET ? addr->sin.sin_port : addr->sin6.sin6_port);
}

/* Allow the user to force the IPv4/IPv6 interface selection */
static int envSocketFamily(void)
{
  int family = -1; // Family selection is not forced, will use first one found
  char* env = getenv("MSCCLPP_SOCKET_FAMILY");
  if (env == NULL)
    return family;

  INFO(MSCCLPP_ENV, "MSCCLPP_SOCKET_FAMILY set by environment to %s", env);

  if (strcmp(env, "AF_INET") == 0)
    family = AF_INET; // IPv4
  else if (strcmp(env, "AF_INET6") == 0)
    family = AF_INET6; // IPv6
  return family;
}

static int findInterfaces(const char* prefixList, char* names, union mscclppSocketAddress* addrs, int sock_family,
                          int maxIfNameSize, int maxIfs)
{
#ifdef ENABLE_TRACE
  char line[SOCKET_NAME_MAXLEN + 1];
#endif
  struct netIf userIfs[MAX_IFS];
  bool searchNot = prefixList && prefixList[0] == '^';
  if (searchNot)
    prefixList++;
  bool searchExact = prefixList && prefixList[0] == '=';
  if (searchExact)
    prefixList++;
  int nUserIfs = parseStringList(prefixList, userIfs, MAX_IFS);

  int found = 0;
  struct ifaddrs *interfaces, *interface;
  getifaddrs(&interfaces);
  for (interface = interfaces; interface && found < maxIfs; interface = interface->ifa_next) {
    if (interface->ifa_addr == NULL)
      continue;

    /* We only support IPv4 & IPv6 */
    int family = interface->ifa_addr->sa_family;
    if (family != AF_INET && family != AF_INET6)
      continue;

    TRACE(MSCCLPP_INIT | MSCCLPP_NET, "Found interface %s:%s", interface->ifa_name,
          mscclppSocketToString((union mscclppSocketAddress*)interface->ifa_addr, line));

    /* Allow the caller to force the socket family type */
    if (sock_family != -1 && family != sock_family)
      continue;

    /* We also need to skip IPv6 loopback interfaces */
    if (family == AF_INET6) {
      struct sockaddr_in6* sa = (struct sockaddr_in6*)(interface->ifa_addr);
      if (IN6_IS_ADDR_LOOPBACK(&sa->sin6_addr))
        continue;
    }

    // check against user specified interfaces
    if (!(matchIfList(interface->ifa_name, -1, userIfs, nUserIfs, searchExact) ^ searchNot)) {
      continue;
    }

    // Check that this interface has not already been saved
    // getifaddrs() normal order appears to be; IPv4, IPv6 Global, IPv6 Link
    bool duplicate = false;
    for (int i = 0; i < found; i++) {
      if (strcmp(interface->ifa_name, names + i * maxIfNameSize) == 0) {
        duplicate = true;
        break;
      }
    }

    if (!duplicate) {
      // Store the interface name
      strncpy(names + found * maxIfNameSize, interface->ifa_name, maxIfNameSize);
      // Store the IP address
      int salen = (family == AF_INET) ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6);
      memcpy(addrs + found, interface->ifa_addr, salen);
      found++;
    }
  }

  freeifaddrs(interfaces);
  return found;
}

static bool matchSubnet(struct ifaddrs local_if, union mscclppSocketAddress* remote)
{
  /* Check family first */
  int family = local_if.ifa_addr->sa_family;
  if (family != remote->sa.sa_family) {
    return false;
  }

  if (family == AF_INET) {
    struct sockaddr_in* local_addr = (struct sockaddr_in*)(local_if.ifa_addr);
    struct sockaddr_in* mask = (struct sockaddr_in*)(local_if.ifa_netmask);
    struct sockaddr_in& remote_addr = remote->sin;
    struct in_addr local_subnet, remote_subnet;
    local_subnet.s_addr = local_addr->sin_addr.s_addr & mask->sin_addr.s_addr;
    remote_subnet.s_addr = remote_addr.sin_addr.s_addr & mask->sin_addr.s_addr;
    return (local_subnet.s_addr ^ remote_subnet.s_addr) ? false : true;
  } else if (family == AF_INET6) {
    struct sockaddr_in6* local_addr = (struct sockaddr_in6*)(local_if.ifa_addr);
    struct sockaddr_in6* mask = (struct sockaddr_in6*)(local_if.ifa_netmask);
    struct sockaddr_in6& remote_addr = remote->sin6;
    struct in6_addr& local_in6 = local_addr->sin6_addr;
    struct in6_addr& mask_in6 = mask->sin6_addr;
    struct in6_addr& remote_in6 = remote_addr.sin6_addr;
    bool same = true;
    int len = 16;                   // IPv6 address is 16 unsigned char
    for (int c = 0; c < len; c++) { // Network byte order is big-endian
      char c1 = local_in6.s6_addr[c] & mask_in6.s6_addr[c];
      char c2 = remote_in6.s6_addr[c] & mask_in6.s6_addr[c];
      if (c1 ^ c2) {
        same = false;
        break;
      }
    }
    // At last, we need to compare scope id
    // Two Link-type addresses can have the same subnet address even though they are not in the same scope
    // For Global type, this field is 0, so a comparison wouldn't matter
    same &= (local_addr->sin6_scope_id == remote_addr.sin6_scope_id);
    return same;
  } else {
    WARN("Net : Unsupported address family type");
    return false;
  }
}

int mscclppFindInterfaceMatchSubnet(char* ifNames, union mscclppSocketAddress* localAddrs,
                                    union mscclppSocketAddress* remoteAddr, int ifNameMaxSize, int maxIfs)
{
#ifdef ENABLE_TRACE
  char line[SOCKET_NAME_MAXLEN + 1];
#endif
  char line_a[SOCKET_NAME_MAXLEN + 1];
  int found = 0;
  struct ifaddrs *interfaces, *interface;
  getifaddrs(&interfaces);
  for (interface = interfaces; interface && !found; interface = interface->ifa_next) {
    if (interface->ifa_addr == NULL)
      continue;

    /* We only support IPv4 & IPv6 */
    int family = interface->ifa_addr->sa_family;
    if (family != AF_INET && family != AF_INET6)
      continue;

    // check against user specified interfaces
    if (!matchSubnet(*interface, remoteAddr)) {
      continue;
    }

    // Store the local IP address
    int salen = (family == AF_INET) ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6);
    memcpy(localAddrs + found, interface->ifa_addr, salen);

    // Store the interface name
    strncpy(ifNames + found * ifNameMaxSize, interface->ifa_name, ifNameMaxSize);

    TRACE(MSCCLPP_INIT | MSCCLPP_NET, "NET : Found interface %s:%s in the same subnet as remote address %s",
          interface->ifa_name, mscclppSocketToString(localAddrs + found, line),
          mscclppSocketToString(remoteAddr, line_a));
    found++;
    if (found == maxIfs)
      break;
  }

  if (found == 0) {
    WARN("Net : No interface found in the same subnet as remote address %s", mscclppSocketToString(remoteAddr, line_a));
  }
  freeifaddrs(interfaces);
  return found;
}

mscclppResult_t mscclppSocketGetAddrFromString(union mscclppSocketAddress* ua, const char* ip_port_pair)
{
  if (!(ip_port_pair && strlen(ip_port_pair) > 1)) {
    WARN("Net : string is null");
    return mscclppInvalidArgument;
  }

  bool ipv6 = ip_port_pair[0] == '[';
  /* Construct the sockaddress structure */
  if (!ipv6) {
    struct netIf ni;
    // parse <ip_or_hostname>:<port> string, expect one pair
    if (parseStringList(ip_port_pair, &ni, 1) != 1) {
      WARN("Net : No valid <IPv4_or_hostname>:<port> pair found");
      return mscclppInvalidArgument;
    }

    struct addrinfo hints, *p;
    int rv;
    memset(&hints, 0, sizeof(hints));
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;

    if ((rv = getaddrinfo(ni.prefix, NULL, &hints, &p)) != 0) {
      WARN("Net : error encountered when getting address info : %s", gai_strerror(rv));
      return mscclppInvalidArgument;
    }

    // use the first
    if (p->ai_family == AF_INET) {
      struct sockaddr_in& sin = ua->sin;
      memcpy(&sin, p->ai_addr, sizeof(struct sockaddr_in));
      sin.sin_family = AF_INET; // IPv4
      // inet_pton(AF_INET, ni.prefix, &(sin.sin_addr));  // IP address
      sin.sin_port = htons(ni.port); // port
    } else if (p->ai_family == AF_INET6) {
      struct sockaddr_in6& sin6 = ua->sin6;
      memcpy(&sin6, p->ai_addr, sizeof(struct sockaddr_in6));
      sin6.sin6_family = AF_INET6;     // IPv6
      sin6.sin6_port = htons(ni.port); // port
      sin6.sin6_flowinfo = 0;          // needed by IPv6, but possibly obsolete
      sin6.sin6_scope_id = 0;          // should be global scope, set to 0
    } else {
      WARN("Net : unsupported IP family");
      return mscclppInvalidArgument;
    }

    freeaddrinfo(p); // all done with this structure

  } else {
    int i, j = -1, len = strlen(ip_port_pair);
    for (i = 1; i < len; i++) {
      if (ip_port_pair[i] == '%')
        j = i;
      if (ip_port_pair[i] == ']')
        break;
    }
    if (i == len) {
      WARN("Net : No valid [IPv6]:port pair found");
      return mscclppInvalidArgument;
    }
    bool global_scope = (j == -1 ? true : false); // If no % found, global scope; otherwise, link scope

    char ip_str[NI_MAXHOST], port_str[NI_MAXSERV], if_name[IFNAMSIZ];
    memset(ip_str, '\0', sizeof(ip_str));
    memset(port_str, '\0', sizeof(port_str));
    memset(if_name, '\0', sizeof(if_name));
    strncpy(ip_str, ip_port_pair + 1, global_scope ? i - 1 : j - 1);
    strncpy(port_str, ip_port_pair + i + 2, len - i - 1);
    int port = atoi(port_str);
    if (!global_scope)
      strncpy(if_name, ip_port_pair + j + 1, i - j - 1); // If not global scope, we need the intf name

    struct sockaddr_in6& sin6 = ua->sin6;
    sin6.sin6_family = AF_INET6;                                     // IPv6
    inet_pton(AF_INET6, ip_str, &(sin6.sin6_addr));                  // IP address
    sin6.sin6_port = htons(port);                                    // port
    sin6.sin6_flowinfo = 0;                                          // needed by IPv6, but possibly obsolete
    sin6.sin6_scope_id = global_scope ? 0 : if_nametoindex(if_name); // 0 if global scope; intf index if link scope
  }
  return mscclppSuccess;
}

int mscclppFindInterfaces(char* ifNames, union mscclppSocketAddress* ifAddrs, int ifNameMaxSize, int maxIfs)
{
  static int shownIfName = 0;
  int nIfs = 0;
  // Allow user to force the INET socket family selection
  int sock_family = envSocketFamily();
  // User specified interface
  char* env = getenv("MSCCLPP_SOCKET_IFNAME");
  if (env && strlen(env) > 1) {
    INFO(MSCCLPP_ENV, "MSCCLPP_SOCKET_IFNAME set by environment to %s", env);
    // Specified by user : find or fail
    if (shownIfName++ == 0)
      INFO(MSCCLPP_NET, "MSCCLPP_SOCKET_IFNAME set to %s", env);
    nIfs = findInterfaces(env, ifNames, ifAddrs, sock_family, ifNameMaxSize, maxIfs);
  } else {
    // Try to automatically pick the right one
    // Start with IB
    nIfs = findInterfaces("ib", ifNames, ifAddrs, sock_family, ifNameMaxSize, maxIfs);
    // else see if we can get some hint from COMM ID
    if (nIfs == 0) {
      char* commId = getenv("MSCCLPP_COMM_ID");
      if (commId && strlen(commId) > 1) {
        INFO(MSCCLPP_ENV, "MSCCLPP_COMM_ID set by environment to %s", commId);
        // Try to find interface that is in the same subnet as the IP in comm id
        union mscclppSocketAddress idAddr;
        mscclppSocketGetAddrFromString(&idAddr, commId);
        nIfs = mscclppFindInterfaceMatchSubnet(ifNames, ifAddrs, &idAddr, ifNameMaxSize, maxIfs);
      }
    }
    // Then look for anything else (but not docker or lo)
    if (nIfs == 0)
      nIfs = findInterfaces("^docker,lo", ifNames, ifAddrs, sock_family, ifNameMaxSize, maxIfs);
    // Finally look for docker, then lo.
    if (nIfs == 0)
      nIfs = findInterfaces("docker", ifNames, ifAddrs, sock_family, ifNameMaxSize, maxIfs);
    if (nIfs == 0)
      nIfs = findInterfaces("lo", ifNames, ifAddrs, sock_family, ifNameMaxSize, maxIfs);
  }
  return nIfs;
}

mscclppResult_t mscclppSocketListen(struct mscclppSocket* sock)
{
  if (sock == NULL) {
    WARN("mscclppSocketListen: pass NULL socket");
    return mscclppInvalidArgument;
  }
  if (sock->fd == -1) {
    WARN("mscclppSocketListen: file descriptor is -1");
    return mscclppInvalidArgument;
  }

  if (socketToPort(&sock->addr)) {
    // Port is forced by env. Make sure we get the port.
    int opt = 1;
#if defined(SO_REUSEPORT)
    SYSCHECK(setsockopt(sock->fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &opt, sizeof(opt)), "setsockopt");
#else
    SYSCHECK(setsockopt(sock->fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)), "setsockopt");
#endif
  }

  // addr port should be 0 (Any port)
  SYSCHECK(bind(sock->fd, &sock->addr.sa, sock->salen), "bind");

  /* Get the assigned Port */
  socklen_t size = sock->salen;
  SYSCHECK(getsockname(sock->fd, &sock->addr.sa, &size), "getsockname");

#ifdef ENABLE_TRACE
  char line[SOCKET_NAME_MAXLEN + 1];
  TRACE(MSCCLPP_INIT | MSCCLPP_NET, "Listening on socket %s", mscclppSocketToString(&sock->addr, line));
#endif

  /* Put the socket in listen mode
   * NB: The backlog will be silently truncated to the value in /proc/sys/net/core/somaxconn
   */
  SYSCHECK(listen(sock->fd, 16384), "listen");
  sock->state = mscclppSocketStateReady;
  return mscclppSuccess;
}

mscclppResult_t mscclppSocketGetAddr(struct mscclppSocket* sock, union mscclppSocketAddress* addr)
{
  if (sock == NULL) {
    WARN("mscclppSocketGetAddr: pass NULL socket");
    return mscclppInvalidArgument;
  }
  if (sock->state != mscclppSocketStateReady)
    return mscclppInternalError;
  memcpy(addr, &sock->addr, sizeof(union mscclppSocketAddress));
  return mscclppSuccess;
}

static mscclppResult_t socketTryAccept(struct mscclppSocket* sock)
{
  static bool timeInitialized = false;
  static mscclppTime_t initTime;
  if (!timeInitialized) {
    timeInitialized = true;
    initTime = getClock();
  }

  mscclppConfig* config = mscclppConfig::getInstance();
  time_t acceptTimeout = config->getBootstrapConnectionTimeoutConfig();
  socklen_t socklen = sizeof(union mscclppSocketAddress);
  sock->fd = accept(sock->acceptFd, &sock->addr.sa, &socklen);
  if (sock->fd != -1) {
    sock->state = mscclppSocketStateAccepted;
    timeInitialized = false;
  } else if (errno != EAGAIN && errno != EWOULDBLOCK) {
    WARN("socketTryAccept: get errno %d that is not EAGAIN or EWOULDBLOCK", errno);
    timeInitialized = false;
    return mscclppSystemError;
  } else if (elapsedClock(getClock(), initTime) > acceptTimeout) {
    WARN("socketTryAccept: exceeded timeout (%ld) sec", acceptTimeout);
    timeInitialized = false;
    return mscclppRemoteError;
  } else {
    usleep(SLEEP_INT);
    if (++sock->acceptRetries % 1000 == 0)
      INFO(MSCCLPP_ALL, "socketTryAccept: Call to try accept returned %s, retrying", strerror(errno));
  }
  return mscclppSuccess;
}

static mscclppResult_t socketFinalizeAccept(struct mscclppSocket* sock)
{
  uint64_t magic;
  enum mscclppSocketType type;
  int received = 0;
  MSCCLPPCHECK(mscclppSocketProgress(MSCCLPP_SOCKET_RECV, sock, &magic, sizeof(magic), &received));
  if (received == 0)
    return mscclppSuccess;
  MSCCLPPCHECK(socketWait(MSCCLPP_SOCKET_RECV, sock, &magic, sizeof(magic), &received));
  if (magic != sock->magic) {
    WARN("socketFinalizeAccept: wrong magic %lx != %lx", magic, sock->magic);
    close(sock->fd);
    sock->fd = -1;
    // Ignore spurious connection and accept again
    sock->state = mscclppSocketStateAccepting;
    return mscclppSuccess;
  } else {
    received = 0;
    MSCCLPPCHECK(socketWait(MSCCLPP_SOCKET_RECV, sock, &type, sizeof(type), &received));
    if (type != sock->type) {
      WARN("socketFinalizeAccept: wrong type %d != %d", type, sock->type);
      sock->state = mscclppSocketStateError;
      close(sock->fd);
      sock->fd = -1;
      return mscclppInternalError;
    } else {
      sock->state = mscclppSocketStateReady;
    }
  }
  return mscclppSuccess;
}

static mscclppResult_t socketStartConnect(struct mscclppSocket* sock)
{
  static bool timeInitialized = false;
  static mscclppTime_t initTime;
  if (!timeInitialized) {
    timeInitialized = true;
    initTime = getClock();
  }

  mscclppConfig* config = mscclppConfig::getInstance();
  time_t acceptTimeout = config->getBootstrapConnectionTimeoutConfig();

  /* blocking/non-blocking connect() is determined by asyncFlag. */
  int ret = connect(sock->fd, &sock->addr.sa, sock->salen);
  if (ret == 0) {
    sock->state = mscclppSocketStateConnected;
    timeInitialized = false;
    return mscclppSuccess;
  } else if (errno == EINPROGRESS) {
    sock->state = mscclppSocketStateConnectPolling;
    return mscclppSuccess;
  } else if (errno == ECONNREFUSED || errno == ETIMEDOUT) {
    if (elapsedClock(getClock(), initTime) > acceptTimeout) {
      WARN("socketStartConnect: exceeded timeout (%ld) sec", acceptTimeout);
      sock->state = mscclppSocketStateError;
      timeInitialized = false;
      return mscclppRemoteError;
    }
    usleep(SLEEP_INT);
    if (++sock->connectRetries % 1000 == 0)
      INFO(MSCCLPP_ALL, "Call to connect returned %s, retrying", strerror(errno));
    return mscclppSuccess;
  } else {
    char line[SOCKET_NAME_MAXLEN + 1];
    sock->state = mscclppSocketStateError;
    WARN("socketStartConnect: Connect to %s failed : %s", mscclppSocketToString(&sock->addr, line), strerror(errno));
    timeInitialized = false;
    return mscclppSystemError;
  }
}

static mscclppResult_t socketPollConnect(struct mscclppSocket* sock)
{
  static bool timeInitialized = false;
  static mscclppTime_t initTime;
  if (!timeInitialized) {
    timeInitialized = true;
    initTime = getClock();
  }

  mscclppConfig* config = mscclppConfig::getInstance();
  time_t acceptTimeout = config->getBootstrapConnectionTimeoutConfig();

  struct pollfd pfd;
  int timeout = 1, ret;
  socklen_t rlen = sizeof(int);

  memset(&pfd, 0, sizeof(struct pollfd));
  pfd.fd = sock->fd;
  pfd.events = POLLOUT;
  SYSCHECK(ret = poll(&pfd, 1, timeout), "poll");
  if (ret == 0) {
    timeInitialized = false;
    return mscclppSuccess;
  }

  /* check socket status */
  EQCHECK(ret == 1 && (pfd.revents & POLLOUT), 0);
  SYSCHECK(getsockopt(sock->fd, SOL_SOCKET, SO_ERROR, (void*)&ret, &rlen), "getsockopt");

  if (ret == 0) {
    timeInitialized = false;
    sock->state = mscclppSocketStateConnected;
  } else if (ret == ECONNREFUSED || ret == ETIMEDOUT) {
    if (elapsedClock(getClock(), initTime) > acceptTimeout) {
      WARN("socketPollConnect: exceeded timeout (%ld) sec", acceptTimeout);
      sock->state = mscclppSocketStateError;
      return mscclppRemoteError;
    }
    if (++sock->connectRetries % 1000 == 0) {
      INFO(MSCCLPP_ALL, "Call to connect returned %s, retrying", strerror(errno));
    }
    usleep(SLEEP_INT);

    close(sock->fd);
    sock->fd = socket(sock->addr.sa.sa_family, SOCK_STREAM, 0);
    sock->state = mscclppSocketStateConnecting;
  } else if (ret != EINPROGRESS) {
    sock->state = mscclppSocketStateError;
    return mscclppSystemError;
  }
  return mscclppSuccess;
}

mscclppResult_t mscclppSocketPollConnect(struct mscclppSocket* sock)
{
  if (sock == NULL) {
    WARN("mscclppSocketPollConnect: pass NULL socket");
    return mscclppInvalidArgument;
  }
  MSCCLPPCHECK(socketPollConnect(sock));
  return mscclppSuccess;
}

static mscclppResult_t socketFinalizeConnect(struct mscclppSocket* sock)
{
  int sent = 0;
  MSCCLPPCHECK(socketProgress(MSCCLPP_SOCKET_SEND, sock, &sock->magic, sizeof(sock->magic), &sent));
  if (sent == 0)
    return mscclppSuccess;
  MSCCLPPCHECK(socketWait(MSCCLPP_SOCKET_SEND, sock, &sock->magic, sizeof(sock->magic), &sent));
  sent = 0;
  MSCCLPPCHECK(socketWait(MSCCLPP_SOCKET_SEND, sock, &sock->type, sizeof(sock->type), &sent));
  sock->state = mscclppSocketStateReady;
  return mscclppSuccess;
}

static mscclppResult_t socketProgressState(struct mscclppSocket* sock)
{
  if (sock->state == mscclppSocketStateAccepting) {
    MSCCLPPCHECK(socketTryAccept(sock));
  }
  if (sock->state == mscclppSocketStateAccepted) {
    MSCCLPPCHECK(socketFinalizeAccept(sock));
  }
  if (sock->state == mscclppSocketStateConnecting) {
    MSCCLPPCHECK(socketStartConnect(sock));
  }
  if (sock->state == mscclppSocketStateConnectPolling) {
    MSCCLPPCHECK(socketPollConnect(sock));
  }
  if (sock->state == mscclppSocketStateConnected) {
    MSCCLPPCHECK(socketFinalizeConnect(sock));
  }
  return mscclppSuccess;
}

// mscclppResult_t mscclppSocketReady(struct mscclppSocket* sock, int *running) {
//   if (sock == NULL) {
//     *running = 0;
//     return mscclppSuccess;
//   }
//   if (sock->state == mscclppSocketStateError || sock->state == mscclppSocketStateClosed) {
//     WARN("mscclppSocketReady: unexpected socket state %d", sock->state);
//     return mscclppRemoteError;
//   }
//   *running = (sock->state == mscclppSocketStateReady) ? 1 : 0;
//   if (*running == 0) {
//     MSCCLPPCHECK(socketProgressState(sock));
//     *running = (sock->state == mscclppSocketStateReady) ? 1 : 0;
//   }
//   return mscclppSuccess;
// }

mscclppResult_t mscclppSocketConnect(struct mscclppSocket* sock)
{
#ifdef ENABLE_TRACE
  char line[SOCKET_NAME_MAXLEN + 1];
#endif
  const int one = 1;

  if (sock == NULL) {
    WARN("mscclppSocketConnect: pass NULL socket");
    return mscclppInvalidArgument;
  }
  if (sock->fd == -1) {
    WARN("mscclppSocketConnect: file descriptor is -1");
    return mscclppInvalidArgument;
  }

  if (sock->state != mscclppSocketStateInitialized) {
    WARN("mscclppSocketConnect: wrong socket state %d", sock->state);
    if (sock->state == mscclppSocketStateError)
      return mscclppRemoteError;
    return mscclppInternalError;
  }
  TRACE(MSCCLPP_INIT | MSCCLPP_NET, "Connecting to socket %s", mscclppSocketToString(&sock->addr, line));

  SYSCHECK(setsockopt(sock->fd, IPPROTO_TCP, TCP_NODELAY, (char*)&one, sizeof(int)), "setsockopt");

  sock->state = mscclppSocketStateConnecting;
  do {
    MSCCLPPCHECK(socketProgressState(sock));
  } while (sock->asyncFlag == 0 && (sock->abortFlag == NULL || *sock->abortFlag == 0) &&
           (sock->state == mscclppSocketStateConnecting || sock->state == mscclppSocketStateConnectPolling ||
            sock->state == mscclppSocketStateConnected));

  if (sock->abortFlag && *sock->abortFlag != 0)
    return mscclppInternalError;

  switch (sock->state) {
  case mscclppSocketStateConnecting:
  case mscclppSocketStateConnectPolling:
  case mscclppSocketStateConnected:
  case mscclppSocketStateReady:
    return mscclppSuccess;
  case mscclppSocketStateError:
    return mscclppSystemError;
  default:
    WARN("mscclppSocketConnect: wrong socket state %d", sock->state);
    return mscclppInternalError;
  }
}

mscclppResult_t mscclppSocketAccept(struct mscclppSocket* sock, struct mscclppSocket* listenSock)
{
  mscclppResult_t ret = mscclppSuccess;

  if (listenSock == NULL || sock == NULL) {
    WARN("mscclppSocketAccept: pass NULL socket");
    ret = mscclppInvalidArgument;
    goto exit;
  }
  if (listenSock->state != mscclppSocketStateReady) {
    WARN("mscclppSocketAccept: wrong socket state %d", listenSock->state);
    if (listenSock->state == mscclppSocketStateError)
      ret = mscclppSystemError;
    else
      ret = mscclppInternalError;
    goto exit;
  }

  if (sock->acceptFd == -1) {
    memcpy(sock, listenSock, sizeof(struct mscclppSocket));
    sock->acceptFd = listenSock->fd;
    sock->state = mscclppSocketStateAccepting;
  }

  do {
    MSCCLPPCHECKGOTO(socketProgressState(sock), ret, exit);
  } while (sock->asyncFlag == 0 && (sock->abortFlag == NULL || *sock->abortFlag == 0) &&
           (sock->state == mscclppSocketStateAccepting || sock->state == mscclppSocketStateAccepted));

  if (sock->abortFlag && *sock->abortFlag != 0)
    return mscclppInternalError;

  switch (sock->state) {
  case mscclppSocketStateAccepting:
  case mscclppSocketStateAccepted:
  case mscclppSocketStateReady:
    ret = mscclppSuccess;
    break;
  case mscclppSocketStateError:
    ret = mscclppSystemError;
    break;
  default:
    WARN("mscclppSocketAccept: wrong socket state %d", sock->state);
    ret = mscclppInternalError;
    break;
  }

exit:
  return ret;
}

mscclppResult_t mscclppSocketInit(struct mscclppSocket* sock, const mscclppSocketAddress* addr, uint64_t magic,
                                  enum mscclppSocketType type, volatile uint32_t* abortFlag, int asyncFlag)
{
  mscclppResult_t ret = mscclppSuccess;

  if (sock == NULL)
    goto exit;
  sock->connectRetries = 0;
  sock->acceptRetries = 0;
  sock->abortFlag = abortFlag;
  sock->asyncFlag = asyncFlag;
  sock->state = mscclppSocketStateInitialized;
  sock->magic = magic;
  sock->type = type;
  sock->fd = -1;
  sock->acceptFd = -1;

  if (addr) {
    /* IPv4/IPv6 support */
    int family;
    memcpy(&sock->addr, addr, sizeof(union mscclppSocketAddress));
    family = sock->addr.sa.sa_family;
    if (family != AF_INET && family != AF_INET6) {
      char line[SOCKET_NAME_MAXLEN + 1];
      WARN("mscclppSocketInit: connecting to address %s with family %d is neither AF_INET(%d) nor AF_INET6(%d)",
           mscclppSocketToString(&sock->addr, line), family, AF_INET, AF_INET6);
      ret = mscclppInternalError;
      goto fail;
    }
    sock->salen = (family == AF_INET) ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6);

    /* Connect to a hostname / port */
    sock->fd = socket(family, SOCK_STREAM, 0);
    if (sock->fd == -1) {
      WARN("mscclppSocketInit: Socket creation failed : %s", strerror(errno));
      ret = mscclppSystemError;
      goto fail;
    }
  } else {
    memset(&sock->addr, 0, sizeof(union mscclppSocketAddress));
  }

  /* Set socket as non-blocking if async or if we need to be able to abort */
  if ((sock->asyncFlag || sock->abortFlag) && sock->fd >= 0) {
    int flags;
    EQCHECKGOTO(flags = fcntl(sock->fd, F_GETFL), -1, ret, fail);
    SYSCHECKGOTO(fcntl(sock->fd, F_SETFL, flags | O_NONBLOCK), ret, fail);
  }

exit:
  return ret;
fail:
  goto exit;
}

mscclppResult_t mscclppSocketProgress(int op, struct mscclppSocket* sock, void* ptr, int size, int* offset)
{
  if (sock == NULL) {
    WARN("mscclppSocketProgress: pass NULL socket");
    return mscclppInvalidArgument;
  }
  MSCCLPPCHECK(socketProgress(op, sock, ptr, size, offset));
  return mscclppSuccess;
}

// mscclppResult_t mscclppSocketWait(int op, struct mscclppSocket* sock, void* ptr, int size, int* offset) {
//   if (sock == NULL) {
//     WARN("mscclppSocketWait: pass NULL socket");
//     return mscclppInvalidArgument;
//   }
//   MSCCLPPCHECK(socketWait(op, sock, ptr, size, offset));
//   return mscclppSuccess;
// }

mscclppResult_t mscclppSocketSend(struct mscclppSocket* sock, void* ptr, int size)
{
  int offset = 0;
  if (sock == NULL) {
    WARN("mscclppSocketSend: pass NULL socket");
    return mscclppInvalidArgument;
  }
  if (sock->state != mscclppSocketStateReady) {
    WARN("mscclppSocketSend: socket state (%d) is not ready", sock->state);
    return mscclppInternalError;
  }
  MSCCLPPCHECK(socketWait(MSCCLPP_SOCKET_SEND, sock, ptr, size, &offset));
  return mscclppSuccess;
}

mscclppResult_t mscclppSocketRecv(struct mscclppSocket* sock, void* ptr, int size)
{
  int offset = 0;
  if (sock == NULL) {
    WARN("mscclppSocketRecv: pass NULL socket");
    return mscclppInvalidArgument;
  }
  if (sock->state != mscclppSocketStateReady) {
    WARN("mscclppSocketRecv: socket state (%d) is not ready", sock->state);
    return mscclppInternalError;
  }
  MSCCLPPCHECK(socketWait(MSCCLPP_SOCKET_RECV, sock, ptr, size, &offset));
  return mscclppSuccess;
}

// Receive or detect connection closed
// mscclppResult_t mscclppSocketTryRecv(struct mscclppSocket* sock, void* ptr, int size, int* closed) {
//   int offset = 0;
//   if (sock == NULL) {
//     WARN("mscclppSocketTryRecv: pass NULL socket");
//     return mscclppInvalidArgument;
//   }
//   *closed = 0;
//   while (offset < size) {
//     MSCCLPPCHECK(socketProgressOpt(MSCCLPP_SOCKET_RECV, sock, ptr, size, &offset, 0, closed));
//     if (*closed) return mscclppSuccess;
//   }
//   return mscclppSuccess;
// }

mscclppResult_t mscclppSocketClose(struct mscclppSocket* sock)
{
  if (sock != NULL) {
    if (sock->fd >= 0)
      close(sock->fd);
    sock->state = mscclppSocketStateClosed;
    sock->fd = -1;
  }
  return mscclppSuccess;
}

// mscclppResult_t mscclppSocketGetFd(struct mscclppSocket* sock, int* fd) {
//   if (sock == NULL) {
//     WARN("mscclppSocketGetFd: pass NULL socket");
//     return mscclppInvalidArgument;
//   }
//   if (fd) *fd = sock->fd;
//   return mscclppSuccess;
// }

// mscclppResult_t mscclppSocketSetFd(int fd, struct mscclppSocket* sock) {
//   if (sock == NULL) {
//     WARN("mscclppSocketGetFd: pass NULL socket");
//     return mscclppInvalidArgument;
//   }
//   sock->fd = fd;
//   return mscclppSuccess;
// }