fix path handling in bind/connect

libc/calls/mkntpath.c

@@ -64,6 +64,54 @@ textwindows size_t __normntpath(char16_t *p, size_t n) {
   return j;
 }
 
+/**
+ * Copies path for unix sockets on Windows NT.
+ *
+ * This function does the following chores:
+ *
+ * 1. Fixing drive letter paths, e.g. `/c/` → `c:\`
+ * 2. Turn `/tmp` into GetTempPath()
+ *
+ * I don't think we need normalize the path here.
+ *
+ * @param path is input unix-style path
+ * @return short count excluding NUL on success, or -1 w/ errno
+ * @error ENAMETOOLONG
+ */
+textwindows int __mkwin32_sun_path(
+    const char *path, char sun_path[hasatleast UNIX_SOCKET_NAME_MAX]) {
+  // 1. Need +1 for NUL-terminator
+  if (!path || (IsAsan() && !__asan_is_valid_str(path))) {
+    return efault();
+  }
+  char16_t tmp_path[UNIX_SOCKET_NAME_MAX];
+  char *p = sun_path;
+  const char *q = path;
+  size_t n = 0;
+  if (IsSlash(q[0]) && IsAlpha(q[1]) && IsSlash(q[2])) {
+    // turn "\c\foo" into "c:\foo"
+    p[0] = q[1];
+    p[1] = ':';
+    p[2] = '\\';
+    p += 3;
+    n = 3;
+  } else if (IsSlash(q[0]) && q[1] == 't' && q[2] == 'm' && q[3] == 'p' &&
+             (IsSlash(q[4]) || !q[4])) {
+    if (!q[4] || !q[5]) return efault();
+    GetTempPath(UNIX_SOCKET_NAME_MAX, tmp_path);
+    n = tprecode16to8(p, UNIX_SOCKET_NAME_MAX, tmp_path).ax;
+    p += n;
+    q += 5;
+  }
+  for (; n < UNIX_SOCKET_NAME_MAX; n++) {
+    if (!(*p++ = *q++)) break;
+  }
+  if (n == UNIX_SOCKET_NAME_MAX) {
+    return efault();
+  }
+  return n;
+}
+
 textwindows int __mkntpath(const char *path,
                            char16_t path16[hasatleast PATH_MAX]) {
   return __mkntpath2(path, path16, -1);

libc/calls/syscall_support-nt.internal.h

@@ -4,12 +4,15 @@
 #include "libc/nt/struct/overlapped.h"
 COSMOPOLITAN_C_START_
 
+#define UNIX_SOCKET_NAME_MAX 108
+
 bool isdirectory_nt(const char *);
 bool isregularfile_nt(const char *);
 bool issymlink_nt(const char *);
 bool32 ntsetprivilege(int64_t, const char16_t *, uint32_t);
 char16_t *__create_pipe_name(char16_t *);
 size_t __normntpath(char16_t *, size_t);
+int __mkwin32_sun_path(const char *, char[hasatleast UNIX_SOCKET_NAME_MAX]);
 int __mkntpath(const char *, char16_t[hasatleast PATH_MAX]);
 int __mkntpath2(const char *, char16_t[hasatleast PATH_MAX], int);
 int __mkntpathath(int64_t, const char *, int, char16_t[hasatleast PATH_MAX]);

libc/sock/bind-nt.c

@@ -16,14 +16,25 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/nt/thunk/msabi.h"
 #include "libc/sock/internal.h"
+#include "libc/sock/struct/sockaddr.h"
 #include "libc/sock/syscall_fd.internal.h"
+#include "libc/sysv/consts/af.h"
 #ifdef __x86_64__
 
 __msabi extern typeof(__sys_bind_nt) *const __imp_bind;
 
 textwindows int sys_bind_nt(struct Fd *f, const void *addr, uint32_t addrsize) {
+  struct sockaddr_un *sun, nt_sun;
+  if (f->family == AF_UNIX && ((struct sockaddr *)addr)->sa_family == AF_UNIX &&
+      addrsize >= sizeof(struct sockaddr_un)) {
+    sun = (struct sockaddr_un *)addr;
+    nt_sun.sun_family = AF_UNIX;
+    if (__mkwin32_sun_path(sun->sun_path, nt_sun.sun_path) == -1) return -1;
+    addr = &nt_sun;
+  }
   if (__imp_bind(f->handle, addr, addrsize) != -1) {
     f->isbound = true;
     return 0;

libc/sock/connect-nt.c

@@ -20,6 +20,7 @@
 #include "libc/atomic.h"
 #include "libc/calls/struct/fd.internal.h"
 #include "libc/calls/struct/sigset.internal.h"
+#include "libc/calls/syscall_support-nt.internal.h"
 #include "libc/cosmo.h"
 #include "libc/errno.h"
 #include "libc/mem/mem.h"
@@ -34,6 +35,7 @@
 #include "libc/sock/struct/sockaddr.h"
 #include "libc/sock/syscall_fd.internal.h"
 #include "libc/sock/wsaid.internal.h"
+#include "libc/sysv/consts/af.h"
 #include "libc/sysv/consts/o.h"
 #include "libc/sysv/errfuns.h"
 
@@ -140,6 +142,14 @@ static textwindows int sys_connect_nt_impl(struct Fd *f, const void *addr,
 
 textwindows int sys_connect_nt(struct Fd *f, const void *addr,
                                uint32_t addrsize) {
+  struct sockaddr_un *sun, nt_sun;
+  if (f->family == AF_UNIX && ((struct sockaddr *)addr)->sa_family == AF_UNIX &&
+      addrsize >= sizeof(struct sockaddr_un)) {
+    sun = (struct sockaddr_un *)addr;
+    nt_sun.sun_family = AF_UNIX;
+    if (__mkwin32_sun_path(sun->sun_path, nt_sun.sun_path) == -1) return -1;
+    addr = &nt_sun;
+  }
   sigset_t mask = __sig_block();
   int rc = sys_connect_nt_impl(f, addr, addrsize, mask);
   __sig_unblock(mask);

test/libc/sock/unix_test.c

@@ -70,17 +70,20 @@ TEST(unix, datagram) {
   munmap(ready, 1);
 }
 
-void StreamServer(atomic_bool *ready) {
+void StreamServer(atomic_bool *ready, const char *path, bool check_path) {
   char buf[256] = {0};
   uint32_t len = sizeof(struct sockaddr_un);
-  struct sockaddr_un addr = {AF_UNIX, "foo.sock"};
+  struct sockaddr_un addr = {AF_UNIX};
+  strcpy(addr.sun_path, path);
   ASSERT_SYS(0, 3, socket(AF_UNIX, SOCK_STREAM, 0));
+  unlink(path);
+  errno = 0;
   ASSERT_SYS(0, 0, bind(3, (void *)&addr, len));
   bzero(&addr, sizeof(addr));
   ASSERT_SYS(0, 0, getsockname(3, (void *)&addr, &len));
-  ASSERT_EQ(2 + 8 + 1, len);
+  if (check_path) ASSERT_EQ(2 + strlen(path) + 1, len);
   ASSERT_EQ(AF_UNIX, addr.sun_family);
-  ASSERT_STREQ("foo.sock", addr.sun_path);
+  if (check_path) ASSERT_STREQ(path, addr.sun_path);
   ASSERT_SYS(0, 0, listen(3, 10));
   bzero(&addr, sizeof(addr));
   len = sizeof(addr);
@@ -101,7 +104,7 @@ TEST(unix, stream) {
   ASSERT_SYS(0, 3, socket(AF_UNIX, SOCK_STREAM, 0));
   if (!fork()) {
     close(3);
-    StreamServer(ready);
+    StreamServer(ready, "foo.sock", true);
     _Exit(0);
   }
   while (!*ready) sched_yield();
@@ -116,6 +119,29 @@ TEST(unix, stream) {
   munmap(ready, 1);
 }
 
+TEST(unix, stream_absolute) {
+  int ws;
+  if (IsWindows() && !IsAtLeastWindows10()) return;
+  atomic_bool *ready = _mapshared(1);
+  // TODO(jart): move this line down when kFdProcess is gone
+  ASSERT_SYS(0, 3, socket(AF_UNIX, SOCK_STREAM, 0));
+  if (!fork()) {
+    close(3);
+    StreamServer(ready, "/tmp/foo.sock", !IsWindows());
+    _Exit(0);
+  }
+  while (!*ready) sched_yield();
+  uint32_t len = sizeof(struct sockaddr_un);
+  struct sockaddr_un addr = {AF_UNIX, "/tmp/foo.sock"};
+  ASSERT_SYS(0, 0, connect(3, (void *)&addr, len));
+  ASSERT_SYS(0, 5, write(3, "hello", 5));
+  ASSERT_SYS(0, 0, close(3));
+  ASSERT_NE(-1, wait(&ws));
+  EXPECT_TRUE(WIFEXITED(ws));
+  EXPECT_EQ(0, WEXITSTATUS(ws));
+  munmap(ready, 1);
+}
+
 TEST(unix, serverGoesDown_deletedSockFile) {  // field of landmine
   if (IsWindows()) return;
   if (IsCygwin()) return;