Keep a list of known vms, and reuse the VM IDs.

This means that when using '-L', the IP addresses of the VMs are stable.

ok reyk@

3 files changed, 44 insertions, 7 deletions

diff --git a/usr.sbin/vmd/config.c b/usr.sbin/vmd/config.c
index 5a3be110df1..c49696cb38d 100644
--- a/usr.sbin/vmd/config.c
+++ b/usr.sbin/vmd/config.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: config.c,v 1.56 2018/11/24 04:51:55 ori Exp $	*/
+/*	$OpenBSD: config.c,v 1.57 2018/11/26 05:44:46 ori Exp $	*/
 
 /*
  * Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org>
@@ -87,7 +87,10 @@ config_init(struct vmd *env)
 	if (what & CONFIG_VMS) {
 		if ((env->vmd_vms = calloc(1, sizeof(*env->vmd_vms))) == NULL)
 			return (-1);
+		if ((env->vmd_known = calloc(1, sizeof(*env->vmd_known))) == NULL)
+			return (-1);
 		TAILQ_INIT(env->vmd_vms);
+		TAILQ_INIT(env->vmd_known);
 	}
 	if (what & CONFIG_SWITCHES) {
 		if ((env->vmd_switches = calloc(1,
@@ -109,6 +112,7 @@ void
 config_purge(struct vmd *env, unsigned int reset)
 {
 	struct privsep		*ps = &env->vmd_ps;
+	struct name2id		*n2i;
 	struct vmd_vm		*vm;
 	struct vmd_switch	*vsw;
 	unsigned int		 what;
@@ -125,6 +129,10 @@ config_purge(struct vmd *env, unsigned int reset)
 		while ((vm = TAILQ_FIRST(env->vmd_vms)) != NULL) {
 			vm_remove(vm, __func__);
 		}
+		while ((n2i = TAILQ_FIRST(env->vmd_known)) != NULL) {
+			TAILQ_REMOVE(env->vmd_known, n2i, entry);
+			free(n2i);
+		}
 		env->vmd_nvm = 0;
 	}
 	if (what & CONFIG_SWITCHES && env->vmd_switches != NULL) {
diff --git a/usr.sbin/vmd/vmd.c b/usr.sbin/vmd/vmd.c
index 9423081df1e..2afc11f63c5 100644
--- a/usr.sbin/vmd/vmd.c
+++ b/usr.sbin/vmd/vmd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vmd.c,v 1.105 2018/11/21 12:31:47 reyk Exp $	*/
+/*	$OpenBSD: vmd.c,v 1.106 2018/11/26 05:44:46 ori Exp $	*/
 
 /*
  * Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org>
@@ -62,6 +62,7 @@ int	 vmd_check_vmh(struct vm_dump_header *);
 int	 vm_instance(struct privsep *, struct vmd_vm **,
 	    struct vmop_create_params *, uid_t);
 int	 vm_checkinsflag(struct vmop_create_params *, unsigned int, uid_t);
+uint32_t vm_claimid(const char *, int);
 
 struct vmd	*env;
 
@@ -1169,6 +1170,28 @@ vm_remove(struct vmd_vm *vm, const char *caller)
 	free(vm);
 }
 
+uint32_t
+vm_claimid(const char *name, int uid)
+{
+	struct name2id *n2i = NULL;
+
+	TAILQ_FOREACH(n2i, env->vmd_known, entry)
+		if (strcmp(n2i->name, name) == 0 && n2i->uid == uid)
+			return n2i->id;
+
+	if (++env->vmd_nvm == 0)
+		fatalx("too many vms");
+	if ((n2i = calloc(1, sizeof(struct name2id))) == NULL)
+		fatalx("could not alloc vm name");
+	n2i->id = env->vmd_nvm;
+	n2i->uid = uid;
+	if (strlcpy(n2i->name, name, sizeof(n2i->name)) >= sizeof(n2i->name))
+		fatalx("overlong vm name");
+	TAILQ_INSERT_TAIL(env->vmd_known, n2i, entry);
+
+	return n2i->id;
+}
+
 int
 vm_register(struct privsep *ps, struct vmop_create_params *vmc,
     struct vmd_vm **ret_vm, uint32_t id, uid_t uid)
@@ -1300,11 +1323,8 @@ vm_register(struct privsep *ps, struct vmop_create_params *vmc,
 	vm->vm_cdrom = -1;
 	vm->vm_iev.ibuf.fd = -1;
 
-	if (++env->vmd_nvm == 0)
-		fatalx("too many vms");
-
 	/* Assign a new internal Id if not specified */
-	vm->vm_vmid = id == 0 ? env->vmd_nvm : id;
+	vm->vm_vmid = (id == 0) ? vm_claimid(vcp->vcp_name, uid) : id;
 
 	log_debug("%s: registering vm %d", __func__, vm->vm_vmid);
 	TAILQ_INSERT_TAIL(env->vmd_vms, vm, vm_entry);
diff --git a/usr.sbin/vmd/vmd.h b/usr.sbin/vmd/vmd.h
index de87e4337ee..c7ee8ecac14 100644
--- a/usr.sbin/vmd/vmd.h
+++ b/usr.sbin/vmd/vmd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vmd.h,v 1.85 2018/11/21 12:31:47 reyk Exp $	*/
+/*	$OpenBSD: vmd.h,v 1.86 2018/11/26 05:44:46 ori Exp $	*/
 
 /*
  * Copyright (c) 2015 Mike Larkin <mlarkin@openbsd.org>
@@ -290,6 +290,14 @@ struct vmd_user {
 };
 TAILQ_HEAD(userlist, vmd_user);
 
+struct name2id {
+	char			name[VMM_MAX_NAME_LEN];
+	int			uid;
+	int32_t			id;
+	TAILQ_ENTRY(name2id)	entry;
+};
+TAILQ_HEAD(name2idlist, name2id);
+
 struct address {
 	struct sockaddr_storage	 ss;
 	int			 prefixlen;
@@ -319,6 +327,7 @@ struct vmd {
 
 	uint32_t		 vmd_nvm;
 	struct vmlist		*vmd_vms;
+	struct name2idlist	*vmd_known;
 	uint32_t		 vmd_nswitches;
 	struct switchlist	*vmd_switches;
 	struct userlist		*vmd_users;