bhyve: Use getaddrinfo(3) consistently for AF_UNIX.

The FreeBSD getaddrinfo(3) function also supports the
AF_UNIX address family. Use it the same way as inet and
inet6 so that we can share the same code. However, the
getaddrinfo(3) accepts an absolute path only. The path
string that follows 'unix:' will be resolved by the
realpath(3) function.

The addrinfo structure is no longer needed after the
bind(2) call. Free it after the bind(2) to remove
freeaddrinfo(3) in the error label code.

The freeaddrinfo(3) function also supports a NULL argument,
as does free(3). No need to check a NULL pointer.

While I'm here, the UNIX domain socket should allow all
users to access it as if it were a TCP port. Changes the
permission to world wide readable and writable.

Signed-off-by: Yuichiro NAITO <naito.yuichiro@gmail.com>

Author: yuichiro-naito

usr.sbin/bhyve/pci_fbuf.c

@@ -42,6 +42,7 @@
 
 #include <errno.h>
 #include <unistd.h>
+#include <libgen.h>
 
 #include "bhyvegc.h"
 #include "bhyverun.h"
@@ -240,6 +241,29 @@ pci_fbuf_baraddr(struct pci_devinst *pi, int baridx, int enabled,
 	}
 }
 
+static char *
+abspath(const char *origpath)
+{
+	char *ret, *dn, *cp, *fn;
+
+	if ((cp = strdup(origpath)) == NULL || cp[0] == '/')
+		return (cp);
+	if ((dn = realpath(dirname(cp), NULL)) == NULL) {
+		EPRINTLN("fbuf: Invalid path: \"%s\"", origpath);
+		goto error;
+	}
+	fn = strrchr(origpath, '/');
+	if (asprintf(&ret, "%s/%s", dn, fn ? fn + 1 : origpath) < 0)
+		goto error;
+	free(dn);
+	free(cp);
+	return (ret);
+
+error:
+	free(dn);
+	free(cp);
+	return (NULL);
+}
 
 static int
 pci_fbuf_parse_config(struct pci_fbuf_softc *sc, nvlist_t *nvl)
@@ -285,17 +309,17 @@ pci_fbuf_parse_config(struct pci_fbuf_softc *sc, nvlist_t *nvl)
 				return (-1);
 			}
 		} else if (strncmp("unix:", value, 5) == 0) {
-			if (strlen(value + 5) > SUNPATHLEN) {
+			if (*(value + 5) == '\0') {
+				EPRINTLN("fbuf: UNIX socket path is empty");
+				return (-1);
+			}
+			sc->rfb_family = AF_UNIX;
+			sc->rfb_host = abspath(value + 5);
+			if (sc->rfb_host && strlen(sc->rfb_host) > SUNPATHLEN) {
 				EPRINTLN(
 				    "fbuf: UNIX socket path too long: \"%s\"",
-				    value + 5);
+				    sc->rfb_host);
 				return (-1);
-			} else if (*(value + 5) == '\0') {
-				EPRINTLN("fbuf: UNIX socket path is empty");
-				return (-1);
-			} else {
-				sc->rfb_family = AF_UNIX;
-				sc->rfb_host = strdup(value + 5);
 			}
 		} else {
 			sc->rfb_family = AF_UNSPEC;

usr.sbin/bhyve/rfb.c

@@ -34,8 +34,8 @@
 #include <sys/endian.h>
 #include <sys/socket.h>
 #include <sys/select.h>
+#include <sys/stat.h>
 #include <sys/time.h>
-#include <sys/un.h>
 #include <arpa/inet.h>
 #include <stdatomic.h>
 #include <machine/cpufunc.h>
@@ -1258,12 +1258,11 @@ int
 rfb_init(sa_family_t family, const char *hostname, int port, int wait,
     const char *password)
 {
-	int e;
+	int e, errno0;
 	char servname[6];
 	struct rfb_softc *rc;
 	struct addrinfo *ai = NULL;
 	struct addrinfo hints;
-	struct sockaddr_un sun;
 	int on = 1;
 	int cnt;
 #ifndef WITHOUT_CAPSICUM
@@ -1304,46 +1303,43 @@ rfb_init(sa_family_t family, const char *hostname, int port, int wait,
 		hostname = "[::1]";
 #endif
 
-	if (family == AF_UNIX) {
-		memset(&sun, 0, sizeof(sun));
-		sun.sun_family = AF_UNIX;
-		if (strlcpy(sun.sun_path, hostname, sizeof(sun.sun_path)) >=
-		    sizeof(sun.sun_path)) {
-			EPRINTLN("rfb: socket path too long");
-			goto error;
-		}
-		rc->sfd = socket(AF_UNIX, SOCK_STREAM, 0);
-	} else {
-		memset(&hints, 0, sizeof(hints));
-		hints.ai_socktype = SOCK_STREAM;
-		hints.ai_family = family;
-		hints.ai_flags = AI_NUMERICHOST | AI_NUMERICSERV | AI_PASSIVE;
-
-		if ((e = getaddrinfo(hostname, servname, &hints, &ai)) != 0) {
-			EPRINTLN("getaddrinfo: %s", gai_strerror(e));
-			goto error;
-		}
-		rc->sfd = socket(ai->ai_family, ai->ai_socktype, 0);
-	}
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_family = family;
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_flags = AI_NUMERICHOST | AI_NUMERICSERV | AI_PASSIVE;
 
+	if ((e = getaddrinfo(hostname, family == AF_UNIX ? NULL : servname,
+		    &hints, &ai)) != 0) {
+		EPRINTLN("getaddrinfo: %s", gai_strerror(e));
+		goto error;
+	}
+	rc->sfd = socket(ai->ai_family, ai->ai_socktype, 0);
 	if (rc->sfd < 0) {
 		perror("socket");
+		freeaddrinfo(ai);
 		goto error;
 	}
 
-	/* No effect for UNIX domain sockets. */
-	setsockopt(rc->sfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
-
-	if (family == AF_UNIX) {
+	if (family == AF_UNIX)
 		unlink(hostname);
-		e = bind(rc->sfd, (struct sockaddr *)&sun, SUN_LEN(&sun));
-	} else
-		e = bind(rc->sfd, ai->ai_addr, ai->ai_addrlen);
+	else
+		setsockopt(rc->sfd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+
+	e = bind(rc->sfd, ai->ai_addr, ai->ai_addrlen);
+	errno0 = errno;
+	freeaddrinfo(ai);
 	if (e < 0) {
+		errno = errno0;
 		perror("bind");
 		goto error;
 	}
 
+	if (family == AF_UNIX && chmod(hostname,
+		S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH) < 0) {
+		perror("chmod");
+		goto error;
+	}
+
 	if (listen(rc->sfd, 1) < 0) {
 		perror("listen");
 		goto error;
@@ -1375,17 +1371,11 @@ rfb_init(sa_family_t family, const char *hostname, int port, int wait,
 		DPRINTF(("rfb client connected"));
 	}
 
-	if (family != AF_UNIX)
-		freeaddrinfo(ai);
 	return (0);
 
  error:
 	if (rc->pixfmt_mtx)
 		pthread_mutex_destroy(&rc->pixfmt_mtx);
-	if (ai != NULL) {
-		assert(family != AF_UNIX);
-		freeaddrinfo(ai);
-	}
 	if (rc->sfd != -1)
 		close(rc->sfd);
 	free(rc->crc);