/* * AppArmor security driver for libvirt * Copyright (C) 2011 Red Hat, Inc. * Copyright (C) 2009-2010 Canonical Ltd. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * Author: * Jamie Strandboge * Based on security_selinux.c by James Morris * * AppArmor security driver. */ #include #include #include #include #include #include #include #include #include "internal.h" #include "security_apparmor.h" #include "util.h" #include "memory.h" #include "virterror_internal.h" #include "datatypes.h" #include "uuid.h" #include "pci.h" #include "hostusb.h" #include "files.h" #include "configmake.h" #include "command.h" #define VIR_FROM_THIS VIR_FROM_SECURITY #define SECURITY_APPARMOR_VOID_DOI "0" #define SECURITY_APPARMOR_NAME "apparmor" #define VIRT_AA_HELPER LIBEXECDIR "/virt-aa-helper" /* Data structure to pass to *FileIterate so we have everything we need */ struct SDPDOP { virSecurityManagerPtr mgr; virDomainObjPtr vm; }; /* * profile_status returns '-1' on error, '0' if loaded * * If check_enforcing is set to '1', then returns '-1' on error, '0' if * loaded in complain mode, and '1' if loaded in enforcing mode. */ static int profile_status(const char *str, const int check_enforcing) { char *content = NULL; char *tmp = NULL; char *etmp = NULL; int rc = -1; /* create string that is ' \0' for accurate matching */ if (virAsprintf(&tmp, "%s ", str) == -1) { virReportOOMError(); return rc; } if (check_enforcing != 0) { /* create string that is ' (enforce)\0' for accurate matching */ if (virAsprintf(&etmp, "%s (enforce)", str) == -1) { VIR_FREE(tmp); virReportOOMError(); return rc; } } if (virFileReadAll(APPARMOR_PROFILES_PATH, MAX_FILE_LEN, &content) < 0) { virReportSystemError(errno, _("Failed to read AppArmor profiles list " "\'%s\'"), APPARMOR_PROFILES_PATH); goto clean; } if (strstr(content, tmp) != NULL) rc = 0; if (check_enforcing != 0) { if (rc == 0 && strstr(content, etmp) != NULL) rc = 1; /* return '1' if loaded and enforcing */ } VIR_FREE(content); clean: VIR_FREE(tmp); VIR_FREE(etmp); return rc; } static int profile_loaded(const char *str) { return profile_status(str, 0); } /* * profile_status_file returns '-1' on error, '0' if file on disk is in * complain mode and '1' if file on disk is in enforcing mode */ static int profile_status_file(const char *str) { char *profile = NULL; char *content = NULL; char *tmp = NULL; int rc = -1; int len; if (virAsprintf(&profile, "%s/%s", APPARMOR_DIR "/libvirt", str) == -1) { virReportOOMError(); return rc; } if (!virFileExists(profile)) goto failed; if ((len = virFileReadAll(profile, MAX_FILE_LEN, &content)) < 0) { virReportSystemError(errno, _("Failed to read \'%s\'"), profile); goto failed; } /* create string that is ' flags=(complain)\0' */ if (virAsprintf(&tmp, " %s flags=(complain)", str) == -1) { virReportOOMError(); goto failed; } if (strstr(content, tmp) != NULL) rc = 0; else rc = 1; failed: VIR_FREE(tmp); VIR_FREE(profile); VIR_FREE(content); return rc; } /* * load (add) a profile. Will create one if necessary */ static int load_profile(virSecurityManagerPtr mgr, const char *profile, virDomainObjPtr vm, const char *fn, bool append) { int rc = -1; bool create = true; char *xml = NULL; virCommandPtr cmd; const char *probe = virSecurityManagerGetAllowDiskFormatProbing(mgr) ? "1" : "0"; xml = virDomainDefFormat(vm->def, VIR_DOMAIN_XML_SECURE); if (!xml) goto clean; if (profile_status_file(profile) >= 0) create = false; cmd = virCommandNewArgList(VIRT_AA_HELPER, "-p", probe, create ? "-c" : "-r", "-u", profile, NULL); if (!create && fn) { if (append) { virCommandAddArgList(cmd, "-F", fn, NULL); } else { virCommandAddArgList(cmd, "-f", fn, NULL); } } virCommandSetInputBuffer(cmd, xml); rc = virCommandRun(cmd, NULL); clean: VIR_FREE(xml); return rc; } static int remove_profile(const char *profile) { int rc = -1; const char * const argv[] = { VIRT_AA_HELPER, "-R", "-u", profile, NULL }; if (virRun(argv, NULL) == 0) rc = 0; return rc; } static char * get_profile_name(virDomainObjPtr vm) { char uuidstr[VIR_UUID_STRING_BUFLEN]; char *name = NULL; virUUIDFormat(vm->def->uuid, uuidstr); if (virAsprintf(&name, "%s%s", AA_PREFIX, uuidstr) < 0) { virReportOOMError(); return NULL; } return name; } /* returns -1 on error or profile for libvirtd is unconfined, 0 if complain * mode and 1 if enforcing. This is required because at present you cannot * aa_change_profile() from a process that is unconfined. */ static int use_apparmor(void) { int rc = -1; char *libvirt_daemon = NULL; if (virFileResolveLink("/proc/self/exe", &libvirt_daemon) < 0) { virSecurityReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("could not find libvirtd")); return rc; } if (access(APPARMOR_PROFILES_PATH, R_OK) != 0) goto cleanup; rc = profile_status(libvirt_daemon, 1); cleanup: VIR_FREE(libvirt_daemon); return rc; } /* reload the profile, adding read/write file specified by fn if it is not * NULL. */ static int reload_profile(virSecurityManagerPtr mgr, virDomainObjPtr vm, const char *fn, bool append) { const virSecurityLabelDefPtr secdef = &vm->def->seclabel; int rc = -1; char *profile_name = NULL; if (secdef->type == VIR_DOMAIN_SECLABEL_STATIC) return 0; if ((profile_name = get_profile_name(vm)) == NULL) return rc; /* Update the profile only if it is loaded */ if (profile_loaded(secdef->imagelabel) >= 0) { if (load_profile(mgr, secdef->imagelabel, vm, fn, append) < 0) { virSecurityReportError(VIR_ERR_INTERNAL_ERROR, _("cannot update AppArmor profile " "\'%s\'"), secdef->imagelabel); goto clean; } } rc = 0; clean: VIR_FREE(profile_name); return rc; } static int AppArmorSetSecurityUSBLabel(usbDevice *dev ATTRIBUTE_UNUSED, const char *file, void *opaque) { struct SDPDOP *ptr = opaque; virDomainObjPtr vm = ptr->vm; if (reload_profile(ptr->mgr, vm, file, true) < 0) { const virSecurityLabelDefPtr secdef = &vm->def->seclabel; virSecurityReportError(VIR_ERR_INTERNAL_ERROR, _("cannot update AppArmor profile " "\'%s\'"), secdef->imagelabel); return -1; } return 0; } static int AppArmorSetSecurityPCILabel(pciDevice *dev ATTRIBUTE_UNUSED, const char *file, void *opaque) { struct SDPDOP *ptr = opaque; virDomainObjPtr vm = ptr->vm; if (reload_profile(ptr->mgr, vm, file, true) < 0) { const virSecurityLabelDefPtr secdef = &vm->def->seclabel; virSecurityReportError(VIR_ERR_INTERNAL_ERROR, _("cannot update AppArmor profile " "\'%s\'"), secdef->imagelabel); return -1; } return 0; } /* Called on libvirtd startup to see if AppArmor is available */ static int AppArmorSecurityManagerProbe(void) { char *template = NULL; int rc = SECURITY_DRIVER_DISABLE; if (use_apparmor() < 0) return rc; /* see if template file exists */ if (virAsprintf(&template, "%s/TEMPLATE", APPARMOR_DIR "/libvirt") == -1) { virReportOOMError(); return rc; } if (!virFileExists(template)) { virSecurityReportError(VIR_ERR_INTERNAL_ERROR, _("template \'%s\' does not exist"), template); goto clean; } rc = SECURITY_DRIVER_ENABLE; clean: VIR_FREE(template); return rc; } /* Security driver initialization. DOI is for 'Domain of Interpretation' and is * currently not used. */ static int AppArmorSecurityManagerOpen(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED) { return 0; } static int AppArmorSecurityManagerClose(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED) { return 0; } static const char * AppArmorSecurityManagerGetModel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED) { return SECURITY_APPARMOR_NAME; } static const char * AppArmorSecurityManagerGetDOI(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED) { return SECURITY_APPARMOR_VOID_DOI; } /* Currently called in qemudStartVMDaemon to setup a 'label'. We look for and * use a profile based on the UUID, otherwise create one based on a template. * Keep in mind that this is called on 'start' with RestoreSecurityLabel being * called on shutdown. */ static int AppArmorGenSecurityLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED, virDomainObjPtr vm) { int rc = -1; char *profile_name = NULL; if (vm->def->seclabel.type == VIR_DOMAIN_SECLABEL_STATIC) return 0; if (vm->def->seclabel.baselabel) { virSecurityReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", _("Cannot set a base label with AppArmour")); return rc; } if ((vm->def->seclabel.label) || (vm->def->seclabel.model) || (vm->def->seclabel.imagelabel)) { virSecurityReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("security label already defined for VM")); return rc; } if ((profile_name = get_profile_name(vm)) == NULL) return rc; vm->def->seclabel.label = strndup(profile_name, strlen(profile_name)); if (!vm->def->seclabel.label) { virReportOOMError(); goto clean; } /* set imagelabel the same as label (but we won't use it) */ vm->def->seclabel.imagelabel = strndup(profile_name, strlen(profile_name)); if (!vm->def->seclabel.imagelabel) { virReportOOMError(); goto err; } vm->def->seclabel.model = strdup(SECURITY_APPARMOR_NAME); if (!vm->def->seclabel.model) { virReportOOMError(); goto err; } /* Now that we have a label, load the profile into the kernel. */ if (load_profile(mgr, vm->def->seclabel.label, vm, NULL, false) < 0) { virSecurityReportError(VIR_ERR_INTERNAL_ERROR, _("cannot load AppArmor profile " "\'%s\'"), vm->def->seclabel.label); goto err; } rc = 0; goto clean; err: VIR_FREE(vm->def->seclabel.label); VIR_FREE(vm->def->seclabel.imagelabel); VIR_FREE(vm->def->seclabel.model); clean: VIR_FREE(profile_name); return rc; } static int AppArmorSetSecurityAllLabel(virSecurityManagerPtr mgr, virDomainObjPtr vm, const char *stdin_path) { if (vm->def->seclabel.type == VIR_DOMAIN_SECLABEL_STATIC) return 0; /* Reload the profile if stdin_path is specified. Note that GenSecurityLabel() will have already been run. */ if (stdin_path) return reload_profile(mgr, vm, stdin_path, true); return 0; } /* Seen with 'virsh dominfo '. This function only called if the VM is * running. */ static int AppArmorGetSecurityProcessLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED, virDomainObjPtr vm, virSecurityLabelPtr sec) { int rc = -1; char *profile_name = NULL; if ((profile_name = get_profile_name(vm)) == NULL) return rc; if (virStrcpy(sec->label, profile_name, VIR_SECURITY_LABEL_BUFLEN) == NULL) { virSecurityReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("error copying profile name")); goto clean; } if ((sec->enforcing = profile_status(profile_name, 1)) < 0) { virSecurityReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("error calling profile_status()")); goto clean; } rc = 0; clean: VIR_FREE(profile_name); return rc; } /* Called on VM shutdown and destroy. See AppArmorGenSecurityLabel (above) for * more details. Currently called via qemudShutdownVMDaemon. */ static int AppArmorReleaseSecurityLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED, virDomainObjPtr vm) { const virSecurityLabelDefPtr secdef = &vm->def->seclabel; VIR_FREE(secdef->model); VIR_FREE(secdef->label); VIR_FREE(secdef->imagelabel); return 0; } static int AppArmorRestoreSecurityAllLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED, virDomainObjPtr vm, int migrated ATTRIBUTE_UNUSED) { const virSecurityLabelDefPtr secdef = &vm->def->seclabel; int rc = 0; if (secdef->type == VIR_DOMAIN_SECLABEL_DYNAMIC) { if ((rc = remove_profile(secdef->label)) != 0) { virSecurityReportError(VIR_ERR_INTERNAL_ERROR, _("could not remove profile for \'%s\'"), secdef->label); } } return rc; } /* Called via virCommand hook. Output goes to * LOCALSTATEDIR/log/libvirt/qemu/.log */ static int AppArmorSetSecurityProcessLabel(virSecurityManagerPtr mgr, virDomainObjPtr vm) { const virSecurityLabelDefPtr secdef = &vm->def->seclabel; int rc = -1; char *profile_name = NULL; if ((profile_name = get_profile_name(vm)) == NULL) return rc; if (STRNEQ(virSecurityManagerGetModel(mgr), secdef->model)) { virSecurityReportError(VIR_ERR_INTERNAL_ERROR, _("security label driver mismatch: " "\'%s\' model configured for domain, but " "hypervisor driver is \'%s\'."), secdef->model, virSecurityManagerGetModel(mgr)); if (use_apparmor() > 0) goto clean; } if (aa_change_profile(profile_name) < 0) { virSecurityReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("error calling aa_change_profile()")); goto clean; } rc = 0; clean: VIR_FREE(profile_name); return rc; } static int AppArmorSetSecuritySocketLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED, virDomainObjPtr vm ATTRIBUTE_UNUSED) { return 0; } static int AppArmorClearSecuritySocketLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED, virDomainObjPtr vm ATTRIBUTE_UNUSED) { return 0; } /* Called when hotplugging */ static int AppArmorRestoreSecurityImageLabel(virSecurityManagerPtr mgr, virDomainObjPtr vm, virDomainDiskDefPtr disk ATTRIBUTE_UNUSED) { return reload_profile(mgr, vm, NULL, false); } /* Called when hotplugging */ static int AppArmorSetSecurityImageLabel(virSecurityManagerPtr mgr, virDomainObjPtr vm, virDomainDiskDefPtr disk) { const virSecurityLabelDefPtr secdef = &vm->def->seclabel; int rc = -1; char *profile_name; if (secdef->type == VIR_DOMAIN_SECLABEL_STATIC) return 0; if (!disk->src || disk->type == VIR_DOMAIN_DISK_TYPE_NETWORK) return 0; if (secdef->imagelabel) { /* if the device doesn't exist, error out */ if (!virFileExists(disk->src)) { virSecurityReportError(VIR_ERR_INTERNAL_ERROR, _("\'%s\' does not exist"), disk->src); return rc; } if ((profile_name = get_profile_name(vm)) == NULL) return rc; /* update the profile only if it is loaded */ if (profile_loaded(secdef->imagelabel) >= 0) { if (load_profile(mgr, secdef->imagelabel, vm, disk->src, false) < 0) { virSecurityReportError(VIR_ERR_INTERNAL_ERROR, _("cannot update AppArmor profile " "\'%s\'"), secdef->imagelabel); goto clean; } } } rc = 0; clean: VIR_FREE(profile_name); return rc; } static int AppArmorSecurityVerify(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED, virDomainDefPtr def) { const virSecurityLabelDefPtr secdef = &def->seclabel; if (secdef->type == VIR_DOMAIN_SECLABEL_STATIC) { if (use_apparmor() < 0 || profile_status(secdef->label, 0) < 0) { virSecurityReportError(VIR_ERR_XML_ERROR, _("Invalid security label \'%s\'"), secdef->label); return -1; } } return 0; } static int AppArmorReserveSecurityLabel(virSecurityManagerPtr mgr ATTRIBUTE_UNUSED, virDomainObjPtr vm ATTRIBUTE_UNUSED) { /* NOOP. Nothing to reserve with AppArmor */ return 0; } static int AppArmorSetSecurityHostdevLabel(virSecurityManagerPtr mgr, virDomainObjPtr vm, virDomainHostdevDefPtr dev) { const virSecurityLabelDefPtr secdef = &vm->def->seclabel; struct SDPDOP *ptr; int ret = -1; if (secdef->type == VIR_DOMAIN_SECLABEL_STATIC) return 0; if (dev->mode != VIR_DOMAIN_HOSTDEV_MODE_SUBSYS) return 0; if (profile_loaded(secdef->imagelabel) < 0) return 0; if (VIR_ALLOC(ptr) < 0) return -1; ptr->mgr = mgr; ptr->vm = vm; switch (dev->source.subsys.type) { case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB: { usbDevice *usb = usbGetDevice(dev->source.subsys.u.usb.bus, dev->source.subsys.u.usb.device); if (!usb) goto done; ret = usbDeviceFileIterate(usb, AppArmorSetSecurityUSBLabel, ptr); usbFreeDevice(usb); break; } case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI: { pciDevice *pci = pciGetDevice(dev->source.subsys.u.pci.domain, dev->source.subsys.u.pci.bus, dev->source.subsys.u.pci.slot, dev->source.subsys.u.pci.function); if (!pci) goto done; ret = pciDeviceFileIterate(pci, AppArmorSetSecurityPCILabel, ptr); pciFreeDevice(pci); break; } default: ret = 0; break; } done: VIR_FREE(ptr); return ret; } static int AppArmorRestoreSecurityHostdevLabel(virSecurityManagerPtr mgr, virDomainObjPtr vm, virDomainHostdevDefPtr dev ATTRIBUTE_UNUSED) { const virSecurityLabelDefPtr secdef = &vm->def->seclabel; if (secdef->type == VIR_DOMAIN_SECLABEL_STATIC) return 0; return reload_profile(mgr, vm, NULL, false); } static int AppArmorSetSavedStateLabel(virSecurityManagerPtr mgr, virDomainObjPtr vm, const char *savefile) { return reload_profile(mgr, vm, savefile, true); } static int AppArmorRestoreSavedStateLabel(virSecurityManagerPtr mgr, virDomainObjPtr vm, const char *savefile ATTRIBUTE_UNUSED) { return reload_profile(mgr, vm, NULL, false); } static int AppArmorSetImageFDLabel(virSecurityManagerPtr mgr, virDomainObjPtr vm, int fd) { int rc = -1; char *proc = NULL; char *fd_path = NULL; const virSecurityLabelDefPtr secdef = &vm->def->seclabel; if (secdef->imagelabel == NULL) return 0; if (virAsprintf(&proc, "/proc/self/fd/%d", fd) == -1) { virReportOOMError(); return rc; } if (virFileResolveLink(proc, &fd_path) < 0) { virSecurityReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("could not find path for descriptor")); return rc; } return reload_profile(mgr, vm, fd_path, true); } static int AppArmorSetProcessFDLabel(virSecurityManagerPtr mgr, virDomainObjPtr vm, int fd) { int rc = -1; char *proc = NULL; char *fd_path = NULL; const virSecurityLabelDefPtr secdef = &vm->def->seclabel; if (secdef->imagelabel == NULL) return 0; if (virAsprintf(&proc, "/proc/self/fd/%d", fd) == -1) { virReportOOMError(); return rc; } if (virFileResolveLink(proc, &fd_path) < 0) { virSecurityReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("could not find path for descriptor")); return rc; } return reload_profile(mgr, vm, fd_path, true); } virSecurityDriver virAppArmorSecurityDriver = { 0, SECURITY_APPARMOR_NAME, AppArmorSecurityManagerProbe, AppArmorSecurityManagerOpen, AppArmorSecurityManagerClose, AppArmorSecurityManagerGetModel, AppArmorSecurityManagerGetDOI, AppArmorSecurityVerify, AppArmorSetSecurityImageLabel, AppArmorRestoreSecurityImageLabel, AppArmorSetSecuritySocketLabel, AppArmorClearSecuritySocketLabel, AppArmorGenSecurityLabel, AppArmorReserveSecurityLabel, AppArmorReleaseSecurityLabel, AppArmorGetSecurityProcessLabel, AppArmorSetSecurityProcessLabel, AppArmorSetSecurityAllLabel, AppArmorRestoreSecurityAllLabel, AppArmorSetSecurityHostdevLabel, AppArmorRestoreSecurityHostdevLabel, AppArmorSetSavedStateLabel, AppArmorRestoreSavedStateLabel, AppArmorSetImageFDLabel, AppArmorSetProcessFDLabel, };