diff options
Diffstat (limited to 'usr.sbin/vmd/config.c')
| -rw-r--r-- | usr.sbin/vmd/config.c | 36 |
1 files changed, 35 insertions, 1 deletions
diff --git a/usr.sbin/vmd/config.c b/usr.sbin/vmd/config.c index eb1aa3a91df..373e027b425 100644 --- a/usr.sbin/vmd/config.c +++ b/usr.sbin/vmd/config.c @@ -1,4 +1,4 @@ -/* $OpenBSD: config.c,v 1.51 2018/10/08 16:32:01 reyk Exp $ */ +/* $OpenBSD: config.c,v 1.52 2018/10/15 10:35:41 reyk Exp $ */ /* * Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org> @@ -193,6 +193,7 @@ config_setvm(struct privsep *ps, struct vmd_vm *vm, uint32_t peerid, uid_t uid) char base[PATH_MAX]; char expanded[PATH_MAX]; unsigned int unit; + struct timeval tv, rate, since_last; errno = 0; @@ -211,6 +212,39 @@ config_setvm(struct privsep *ps, struct vmd_vm *vm, uint32_t peerid, uid_t uid) } } + /* + * Rate-limit the VM so that it cannot restart in a loop: + * if the VM restarts after less than VM_START_RATE_SEC seconds, + * we increment the limit counter. After VM_START_RATE_LIMIT + * of suchs fast reboots the VM is stopped. + */ + getmonotime(&tv); + if (vm->vm_start_tv.tv_sec) { + timersub(&tv, &vm->vm_start_tv, &since_last); + + rate.tv_sec = VM_START_RATE_SEC; + rate.tv_usec = 0; + if (timercmp(&since_last, &rate, <)) + vm->vm_start_limit++; + else { + /* Reset counter */ + vm->vm_start_limit = 0; + } + + log_debug("%s: vm %u restarted after %lld.%ld seconds," + " limit %d/%d", __func__, vcp->vcp_id, since_last.tv_sec, + since_last.tv_usec, vm->vm_start_limit, + VM_START_RATE_LIMIT); + + if (vm->vm_start_limit >= VM_START_RATE_LIMIT) { + log_warnx("%s: vm %u restarted too quickly", + __func__, vcp->vcp_id); + errno = EPERM; + goto fail; + } + } + vm->vm_start_tv = tv; + for (i = 0; i < VMM_MAX_DISKS_PER_VM; i++) for (j = 0; j < VM_MAX_BASE_PER_DISK; j++) diskfds[i][j] = -1; |