doc: bump min supported linux and freebsd versions (#3830)

The old Linux baseline was essentially RHEL 6 but that distro has been
out of support for two years now. Move to RHEL 7.

This commit also moves FreeBSD to tier 2 because it isn't actually
part of libuv's CI matrix, only Node's.

Fixes: https://github.com/libuv/libuv/issues/3822

SUPPORTED_PLATFORMS.md

@@ -2,10 +2,10 @@
 
 |  System | Support type | Supported versions | Notes |
 |---|---|---|---|
-| GNU/Linux | Tier 1 | Linux >= 2.6.32 with glibc >= 2.12 | |
+| GNU/Linux | Tier 1 | Linux >= 3.10 with glibc >= 2.17 | |
 | macOS | Tier 1 | macOS >= 10.15 | Current and previous macOS release |
 | Windows | Tier 1 | >= Windows 8 | VS 2015 and later are supported |
-| FreeBSD | Tier 1 | >= 10 | |
+| FreeBSD | Tier 2 | >= 12 | |
 | AIX | Tier 2 | >= 6 | Maintainers: @libuv/aix |
 | IBM i | Tier 2 | >= IBM i 7.2 | Maintainers: @libuv/ibmi |
 | z/OS | Tier 2 | >= V2R2 | Maintainers: @libuv/zos |

src/unix/freebsd.c

@@ -269,30 +269,6 @@ int uv_cpu_info(uv_cpu_info_t** cpu_infos, int* count) {
 }
 
 
-int uv__sendmmsg(int fd, struct uv__mmsghdr* mmsg, unsigned int vlen) {
-#if __FreeBSD__ >= 11 && !defined(__DragonFly__)
-  return sendmmsg(fd,
-                  (struct mmsghdr*) mmsg,
-                  vlen,
-                  0 /* flags */);
-#else
-  return errno = ENOSYS, -1;
-#endif
-}
-
-
-int uv__recvmmsg(int fd, struct uv__mmsghdr* mmsg, unsigned int vlen) {
-#if __FreeBSD__ >= 11 && !defined(__DragonFly__)
-  return recvmmsg(fd,
-                  (struct mmsghdr*) mmsg,
-                  vlen,
-                  0 /* flags */,
-                  NULL /* timeout */);
-#else
-  return errno = ENOSYS, -1;
-#endif
-}
-
 ssize_t
 uv__fs_copy_file_range(int fd_in,
                        off_t* off_in,

src/unix/internal.h

@@ -411,22 +411,6 @@ int uv__getsockpeername(const uv_handle_t* handle,
                         struct sockaddr* name,
                         int* namelen);
 
-#if defined(__linux__)            ||                                      \
-    defined(__FreeBSD__)          ||                                      \
-    defined(__FreeBSD_kernel__)   ||                                       \
-    defined(__DragonFly__)
-#define HAVE_MMSG 1
-struct uv__mmsghdr {
-  struct msghdr msg_hdr;
-  unsigned int msg_len;
-};
-
-int uv__recvmmsg(int fd, struct uv__mmsghdr* mmsg, unsigned int vlen);
-int uv__sendmmsg(int fd, struct uv__mmsghdr* mmsg, unsigned int vlen);
-#else
-#define HAVE_MMSG 0
-#endif
-
 #if defined(__sun)
 #if !defined(_POSIX_VERSION) || _POSIX_VERSION < 200809L
 size_t strnlen(const char* s, size_t maxlen);

src/unix/linux.c

@@ -55,22 +55,6 @@
 # endif
 #endif /* __arm__ */
 
-#ifndef __NR_recvmmsg
-# if defined(__x86_64__)
-#  define __NR_recvmmsg 299
-# elif defined(__arm__)
-#  define __NR_recvmmsg (UV_SYSCALL_BASE + 365)
-# endif
-#endif /* __NR_recvmsg */
-
-#ifndef __NR_sendmmsg
-# if defined(__x86_64__)
-#  define __NR_sendmmsg 307
-# elif defined(__arm__)
-#  define __NR_sendmmsg (UV_SYSCALL_BASE + 374)
-# endif
-#endif /* __NR_sendmmsg */
-
 #ifndef __NR_copy_file_range
 # if defined(__x86_64__)
 #  define __NR_copy_file_range 326
@@ -1796,89 +1780,3 @@ int uv_fs_event_stop(uv_fs_event_t* handle) {
 void uv__fs_event_close(uv_fs_event_t* handle) {
   uv_fs_event_stop(handle);
 }
-
-
-int uv__sendmmsg(int fd, struct uv__mmsghdr* mmsg, unsigned int vlen) {
-#if defined(__i386__)
-  unsigned long args[4];
-  int rc;
-
-  args[0] = (unsigned long) fd;
-  args[1] = (unsigned long) mmsg;
-  args[2] = (unsigned long) vlen;
-  args[3] = /* flags */ 0;
-
-  /* socketcall() raises EINVAL when SYS_SENDMMSG is not supported. */
-  rc = syscall(/* __NR_socketcall */ 102, 20 /* SYS_SENDMMSG */, args);
-  if (rc == -1)
-    if (errno == EINVAL)
-      errno = ENOSYS;
-
-  return rc;
-#elif defined(__NR_sendmmsg)
-  return syscall(__NR_sendmmsg, fd, mmsg, vlen, /* flags */ 0);
-#else
-  return errno = ENOSYS, -1;
-#endif
-}
-
-
-static void uv__recvmmsg_unpoison(struct uv__mmsghdr* mmsg, int rc) {
-  struct uv__mmsghdr* m;
-  struct msghdr* h;
-  struct iovec* v;
-  size_t j;
-  int i;
-
-  for (i = 0; i < rc; i++) {
-    m = mmsg + i;
-    uv__msan_unpoison(m, sizeof(*m));
-
-    h = &m->msg_hdr;
-    if (h->msg_name != NULL)
-      uv__msan_unpoison(h->msg_name, h->msg_namelen);
-
-    if (h->msg_iov != NULL)
-      uv__msan_unpoison(h->msg_iov, h->msg_iovlen * sizeof(*h->msg_iov));
-
-    for (j = 0; j < h->msg_iovlen; j++) {
-      v = h->msg_iov + j;
-      uv__msan_unpoison(v->iov_base, v->iov_len);
-    }
-
-    if (h->msg_control != NULL)
-      uv__msan_unpoison(h->msg_control, h->msg_controllen);
-  }
-}
-
-
-int uv__recvmmsg(int fd, struct uv__mmsghdr* mmsg, unsigned int vlen) {
-#if defined(__i386__)
-  unsigned long args[5];
-  int rc;
-
-  args[0] = (unsigned long) fd;
-  args[1] = (unsigned long) mmsg;
-  args[2] = (unsigned long) vlen;
-  args[3] = /* flags */ 0;
-  args[4] = /* timeout */ 0;
-
-  /* socketcall() raises EINVAL when SYS_RECVMMSG is not supported. */
-  rc = syscall(/* __NR_socketcall */ 102, 19 /* SYS_RECVMMSG */, args);
-  uv__recvmmsg_unpoison(mmsg, rc);
-  if (rc == -1)
-    if (errno == EINVAL)
-      errno = ENOSYS;
-
-  return rc;
-#elif defined(__NR_recvmmsg)
-  int rc;
-
-  rc = syscall(__NR_recvmmsg, fd, mmsg, vlen, /* flags */ 0, /* timeout */ 0);
-  uv__recvmmsg_unpoison(mmsg, rc);
-
-  return rc;
-#else
-  return errno = ENOSYS, -1;
-#endif
-}

src/unix/udp.c

@@ -54,36 +54,6 @@ static int uv__udp_maybe_deferred_bind(uv_udp_t* handle,
                                        int domain,
                                        unsigned int flags);
 
-#if HAVE_MMSG
-
-#define UV__MMSG_MAXWIDTH 20
-
-static int uv__udp_recvmmsg(uv_udp_t* handle, uv_buf_t* buf);
-static void uv__udp_sendmmsg(uv_udp_t* handle);
-
-static int uv__recvmmsg_avail;
-static int uv__sendmmsg_avail;
-static uv_once_t once = UV_ONCE_INIT;
-
-static void uv__udp_mmsg_init(void) {
-  int ret;
-  int s;
-  s = uv__socket(AF_INET, SOCK_DGRAM, 0);
-  if (s < 0)
-    return;
-  ret = uv__sendmmsg(s, NULL, 0);
-  if (ret == 0 || errno != ENOSYS) {
-    uv__sendmmsg_avail = 1;
-    uv__recvmmsg_avail = 1;
-  } else {
-    ret = uv__recvmmsg(s, NULL, 0);
-    if (ret == 0 || errno != ENOSYS)
-      uv__recvmmsg_avail = 1;
-  }
-  uv__close(s);
-}
-
-#endif
 
 void uv__udp_close(uv_udp_t* handle) {
   uv__io_close(handle->loop, &handle->io_watcher);
@@ -183,11 +153,11 @@ static void uv__udp_io(uv_loop_t* loop, uv__io_t* w, unsigned int revents) {
   }
 }
 
-#if HAVE_MMSG
 static int uv__udp_recvmmsg(uv_udp_t* handle, uv_buf_t* buf) {
-  struct sockaddr_in6 peers[UV__MMSG_MAXWIDTH];
+#if defined(__linux__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
-  struct iovec iov[UV__MMSG_MAXWIDTH];
+  struct sockaddr_in6 peers[20];
-  struct uv__mmsghdr msgs[UV__MMSG_MAXWIDTH];
+  struct iovec iov[ARRAY_SIZE(peers)];
+  struct mmsghdr msgs[ARRAY_SIZE(peers)];
   ssize_t nread;
   uv_buf_t chunk_buf;
   size_t chunks;
@@ -212,7 +182,7 @@ static int uv__udp_recvmmsg(uv_udp_t* handle, uv_buf_t* buf) {
   }
 
   do
-    nread = uv__recvmmsg(handle->io_watcher.fd, msgs, chunks);
+    nread = recvmmsg(handle->io_watcher.fd, msgs, chunks, 0, NULL);
   while (nread == -1 && errno == EINTR);
 
   if (nread < 1) {
@@ -240,8 +210,10 @@ static int uv__udp_recvmmsg(uv_udp_t* handle, uv_buf_t* buf) {
       handle->recv_cb(handle, 0, buf, NULL, UV_UDP_MMSG_FREE);
   }
   return nread;
+#else  /* __linux__ || ____FreeBSD__ || __FreeBSD_kernel__ */
+  return UV_ENOSYS;
+#endif  /* __linux__ || ____FreeBSD__ || __FreeBSD_kernel__ */
 }
-#endif
 
 static void uv__udp_recvmsg(uv_udp_t* handle) {
   struct sockaddr_storage peer;
@@ -268,14 +240,12 @@ static void uv__udp_recvmsg(uv_udp_t* handle) {
     }
     assert(buf.base != NULL);
 
-#if HAVE_MMSG
     if (uv_udp_using_recvmmsg(handle)) {
       nread = uv__udp_recvmmsg(handle, &buf);
       if (nread > 0)
         count -= nread;
       continue;
     }
-#endif
 
     memset(&h, 0, sizeof(h));
     memset(&peer, 0, sizeof(peer));
@@ -311,11 +281,11 @@ static void uv__udp_recvmsg(uv_udp_t* handle) {
       && handle->recv_cb != NULL);
 }
 
-#if HAVE_MMSG
+static void uv__udp_sendmsg(uv_udp_t* handle) {
-static void uv__udp_sendmmsg(uv_udp_t* handle) {
+#if defined(__linux__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
   uv_udp_send_t* req;
-  struct uv__mmsghdr h[UV__MMSG_MAXWIDTH];
+  struct mmsghdr h[20];
-  struct uv__mmsghdr *p;
+  struct mmsghdr* p;
   QUEUE* q;
   ssize_t npkts;
   size_t pkts;
@@ -326,7 +296,7 @@ static void uv__udp_sendmmsg(uv_udp_t* handle) {
 
 write_queue_drain:
   for (pkts = 0, q = QUEUE_HEAD(&handle->write_queue);
-       pkts < UV__MMSG_MAXWIDTH && q != &handle->write_queue;
+       pkts < ARRAY_SIZE(h) && q != &handle->write_queue;
        ++pkts, q = QUEUE_HEAD(q)) {
     assert(q != NULL);
     req = QUEUE_DATA(q, uv_udp_send_t, queue);
@@ -355,7 +325,7 @@ write_queue_drain:
   }
 
   do
-    npkts = uv__sendmmsg(handle->io_watcher.fd, h, pkts);
+    npkts = sendmmsg(handle->io_watcher.fd, h, pkts, 0);
   while (npkts == -1 && errno == EINTR);
 
   if (npkts < 1) {
@@ -401,24 +371,12 @@ write_queue_drain:
   if (!QUEUE_EMPTY(&handle->write_queue))
     goto write_queue_drain;
   uv__io_feed(handle->loop, &handle->io_watcher);
-  return;
+#else  /* __linux__ || ____FreeBSD__ || __FreeBSD_kernel__ */
-}
-#endif
-
-static void uv__udp_sendmsg(uv_udp_t* handle) {
   uv_udp_send_t* req;
   struct msghdr h;
   QUEUE* q;
   ssize_t size;
 
-#if HAVE_MMSG
-  uv_once(&once, uv__udp_mmsg_init);
-  if (uv__sendmmsg_avail) {
-    uv__udp_sendmmsg(handle);
-    return;
-  }
-#endif
-
   while (!QUEUE_EMPTY(&handle->write_queue)) {
     q = QUEUE_HEAD(&handle->write_queue);
     assert(q != NULL);
@@ -466,6 +424,7 @@ static void uv__udp_sendmsg(uv_udp_t* handle) {
     QUEUE_INSERT_TAIL(&handle->write_completed_queue, &req->queue);
     uv__io_feed(handle->loop, &handle->io_watcher);
   }
+#endif  /* __linux__ || ____FreeBSD__ || __FreeBSD_kernel__ */
 }
 
 /* On the BSDs, SO_REUSEPORT implies SO_REUSEADDR but with some additional
@@ -1061,11 +1020,9 @@ int uv__udp_init_ex(uv_loop_t* loop,
 
 
 int uv_udp_using_recvmmsg(const uv_udp_t* handle) {
-#if HAVE_MMSG
+#if defined(__linux__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
-  if (handle->flags & UV_HANDLE_UDP_RECVMMSG) {
+  if (handle->flags & UV_HANDLE_UDP_RECVMMSG)
-    uv_once(&once, uv__udp_mmsg_init);
+    return 1;
-    return uv__recvmmsg_avail;
-  }
 #endif
   return 0;
 }