/*- * Copyright (c) 1999 Poul-Henning Kamp. * Copyright (c) 2008 Bjoern A. Zeeb. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include __FBSDID("$FreeBSD$"); #include "opt_ddb.h" #include "opt_inet.h" #include "opt_inet6.h" #include "opt_mac.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef DDB #include #ifdef INET6 #include #endif /* INET6 */ #endif /* DDB */ #include MALLOC_DEFINE(M_PRISON, "prison", "Prison structures"); SYSCTL_NODE(_security, OID_AUTO, jail, CTLFLAG_RW, 0, "Jail rules"); int jail_set_hostname_allowed = 1; SYSCTL_INT(_security_jail, OID_AUTO, set_hostname_allowed, CTLFLAG_RW, &jail_set_hostname_allowed, 0, "Processes in jail can set their hostnames"); int jail_socket_unixiproute_only = 1; SYSCTL_INT(_security_jail, OID_AUTO, socket_unixiproute_only, CTLFLAG_RW, &jail_socket_unixiproute_only, 0, "Processes in jail are limited to creating UNIX/IP/route sockets only"); int jail_sysvipc_allowed = 0; SYSCTL_INT(_security_jail, OID_AUTO, sysvipc_allowed, CTLFLAG_RW, &jail_sysvipc_allowed, 0, "Processes in jail can use System V IPC primitives"); static int jail_enforce_statfs = 2; SYSCTL_INT(_security_jail, OID_AUTO, enforce_statfs, CTLFLAG_RW, &jail_enforce_statfs, 0, "Processes in jail cannot see all mounted file systems"); int jail_allow_raw_sockets = 0; SYSCTL_INT(_security_jail, OID_AUTO, allow_raw_sockets, CTLFLAG_RW, &jail_allow_raw_sockets, 0, "Prison root can create raw sockets"); int jail_chflags_allowed = 0; SYSCTL_INT(_security_jail, OID_AUTO, chflags_allowed, CTLFLAG_RW, &jail_chflags_allowed, 0, "Processes in jail can alter system file flags"); int jail_mount_allowed = 0; SYSCTL_INT(_security_jail, OID_AUTO, mount_allowed, CTLFLAG_RW, &jail_mount_allowed, 0, "Processes in jail can mount/unmount jail-friendly file systems"); int jail_max_af_ips = 255; SYSCTL_INT(_security_jail, OID_AUTO, jail_max_af_ips, CTLFLAG_RW, &jail_max_af_ips, 0, "Number of IP addresses a jail may have at most per address family"); /* allprison, lastprid, and prisoncount are protected by allprison_lock. */ struct prisonlist allprison; struct sx allprison_lock; int lastprid = 0; int prisoncount = 0; static void init_prison(void *); static void prison_complete(void *context, int pending); static int sysctl_jail_list(SYSCTL_HANDLER_ARGS); #ifdef INET static int _prison_check_ip4(struct prison *, struct in_addr *); #endif #ifdef INET6 static int _prison_check_ip6(struct prison *, struct in6_addr *); #endif static void init_prison(void *data __unused) { sx_init(&allprison_lock, "allprison"); LIST_INIT(&allprison); } SYSINIT(prison, SI_SUB_INTRINSIC, SI_ORDER_ANY, init_prison, NULL); #ifdef INET static int qcmp_v4(const void *ip1, const void *ip2) { in_addr_t iaa, iab; /* * We need to compare in HBO here to get the list sorted as expected * by the result of the code. Sorting NBO addresses gives you * interesting results. If you do not understand, do not try. */ iaa = ntohl(((const struct in_addr *)ip1)->s_addr); iab = ntohl(((const struct in_addr *)ip2)->s_addr); /* * Do not simply return the difference of the two numbers, the int is * not wide enough. */ if (iaa > iab) return (1); else if (iaa < iab) return (-1); else return (0); } #endif #ifdef INET6 static int qcmp_v6(const void *ip1, const void *ip2) { const struct in6_addr *ia6a, *ia6b; int i, rc; ia6a = (const struct in6_addr *)ip1; ia6b = (const struct in6_addr *)ip2; rc = 0; for (i=0; rc == 0 && i < sizeof(struct in6_addr); i++) { if (ia6a->s6_addr[i] > ia6b->s6_addr[i]) rc = 1; else if (ia6a->s6_addr[i] < ia6b->s6_addr[i]) rc = -1; } return (rc); } #endif #if defined(INET) || defined(INET6) static int prison_check_conflicting_ips(struct prison *p) { struct prison *pr; int i; sx_assert(&allprison_lock, SX_LOCKED); if (p->pr_ip4s == 0 && p->pr_ip6s == 0) return (0); LIST_FOREACH(pr, &allprison, pr_list) { /* * Skip 'dying' prisons to avoid problems when * restarting multi-IP jails. */ if (pr->pr_state == PRISON_STATE_DYING) continue; /* * We permit conflicting IPs if there is no * more than 1 IP on eeach jail. * In case there is one duplicate on a jail with * more than one IP stop checking and return error. */ #ifdef INET if ((p->pr_ip4s >= 1 && pr->pr_ip4s > 1) || (p->pr_ip4s > 1 && pr->pr_ip4s >= 1)) { for (i = 0; i < p->pr_ip4s; i++) { if (_prison_check_ip4(pr, &p->pr_ip4[i])) return (EINVAL); } } #endif #ifdef INET6 if ((p->pr_ip6s >= 1 && pr->pr_ip6s > 1) || (p->pr_ip6s > 1 && pr->pr_ip6s >= 1)) { for (i = 0; i < p->pr_ip6s; i++) { if (_prison_check_ip6(pr, &p->pr_ip6[i])) return (EINVAL); } } #endif } return (0); } static int jail_copyin_ips(struct jail *j) { #ifdef INET struct in_addr *ip4; #endif #ifdef INET6 struct in6_addr *ip6; #endif int error, i; /* * Copy in addresses, check for duplicate addresses and do some * simple 0 and broadcast checks. If users give other bogus addresses * it is their problem. * * IP addresses are all sorted but ip[0] to preserve the primary IP * address as given from userland. This special IP is used for * unbound outgoing connections as well for "loopback" traffic. */ #ifdef INET ip4 = NULL; #endif #ifdef INET6 ip6 = NULL; #endif #ifdef INET if (j->ip4s > 0) { ip4 = (struct in_addr *)malloc(j->ip4s * sizeof(struct in_addr), M_PRISON, M_WAITOK | M_ZERO); error = copyin(j->ip4, ip4, j->ip4s * sizeof(struct in_addr)); if (error) goto e_free_ip; /* Sort all but the first IPv4 address. */ if (j->ip4s > 1) qsort((ip4 + 1), j->ip4s - 1, sizeof(struct in_addr), qcmp_v4); /* * We do not have to care about byte order for these checks * so we will do them in NBO. */ for (i=0; iip4s; i++) { if (ip4[i].s_addr == htonl(INADDR_ANY) || ip4[i].s_addr == htonl(INADDR_BROADCAST)) { error = EINVAL; goto e_free_ip; } if ((i+1) < j->ip4s && (ip4[0].s_addr == ip4[i+1].s_addr || ip4[i].s_addr == ip4[i+1].s_addr)) { error = EINVAL; goto e_free_ip; } } j->ip4 = ip4; } else j->ip4 = NULL; #endif #ifdef INET6 if (j->ip6s > 0) { ip6 = (struct in6_addr *)malloc(j->ip6s * sizeof(struct in6_addr), M_PRISON, M_WAITOK | M_ZERO); error = copyin(j->ip6, ip6, j->ip6s * sizeof(struct in6_addr)); if (error) goto e_free_ip; /* Sort all but the first IPv6 address. */ if (j->ip6s > 1) qsort((ip6 + 1), j->ip6s - 1, sizeof(struct in6_addr), qcmp_v6); for (i=0; iip6s; i++) { if (IN6_IS_ADDR_UNSPECIFIED(&ip6[i])) { error = EINVAL; goto e_free_ip; } if ((i+1) < j->ip6s && (IN6_ARE_ADDR_EQUAL(&ip6[0], &ip6[i+1]) || IN6_ARE_ADDR_EQUAL(&ip6[i], &ip6[i+1]))) { error = EINVAL; goto e_free_ip; } } j->ip6 = ip6; } else j->ip6 = NULL; #endif return (0); e_free_ip: #ifdef INET6 free(ip6, M_PRISON); j->ip6 = NULL; #endif #ifdef INET free(ip4, M_PRISON); j->ip4 = NULL; #endif return (error); } #endif /* INET || INET6 */ static int jail_handle_ips(struct jail *j) { #if defined(INET) || defined(INET6) int error; #endif /* * Finish conversion for older versions, copyin and setup IPs. */ switch (j->version) { case 0: { #ifdef INET /* FreeBSD single IPv4 jails. */ struct in_addr *ip4; if (j->ip4s == INADDR_ANY || j->ip4s == INADDR_BROADCAST) return (EINVAL); ip4 = (struct in_addr *)malloc(sizeof(struct in_addr), M_PRISON, M_WAITOK | M_ZERO); /* * Jail version 0 still used HBO for the IPv4 address. */ ip4->s_addr = htonl(j->ip4s); j->ip4s = 1; j->ip4 = ip4; break; #else return (EINVAL); #endif } case 1: /* * Version 1 was used by multi-IPv4 jail implementations * that never made it into the official kernel. * We should never hit this here; jail() should catch it. */ return (EINVAL); case 2: /* JAIL_API_VERSION */ /* FreeBSD multi-IPv4/IPv6,noIP jails. */ #if defined(INET) || defined(INET6) #ifdef INET if (j->ip4s > jail_max_af_ips) return (EINVAL); #else if (j->ip4s != 0) return (EINVAL); #endif #ifdef INET6 if (j->ip6s > jail_max_af_ips) return (EINVAL); #else if (j->ip6s != 0) return (EINVAL); #endif error = jail_copyin_ips(j); if (error) return (error); #endif break; default: /* Sci-Fi jails are not supported, sorry. */ return (EINVAL); } return (0); } /* * struct jail_args { * struct jail *jail; * }; */ int jail(struct thread *td, struct jail_args *uap) { uint32_t version; int error; struct jail j; error = copyin(uap->jail, &version, sizeof(uint32_t)); if (error) return (error); switch (version) { case 0: /* FreeBSD single IPv4 jails. */ { struct jail_v0 j0; bzero(&j, sizeof(struct jail)); error = copyin(uap->jail, &j0, sizeof(struct jail_v0)); if (error) return (error); j.version = j0.version; j.path = j0.path; j.hostname = j0.hostname; j.ip4s = j0.ip_number; break; } case 1: /* * Version 1 was used by multi-IPv4 jail implementations * that never made it into the official kernel. */ return (EINVAL); case 2: /* JAIL_API_VERSION */ /* FreeBSD multi-IPv4/IPv6,noIP jails. */ error = copyin(uap->jail, &j, sizeof(struct jail)); if (error) return (error); break; default: /* Sci-Fi jails are not supported, sorry. */ return (EINVAL); } return (kern_jail(td, &j)); } int kern_jail(struct thread *td, struct jail *j) { struct nameidata nd; struct prison *pr, *tpr; struct jail_attach_args jaa; int vfslocked, error, tryprid; KASSERT(j != NULL, ("%s: j is NULL", __func__)); /* Handle addresses - convert old structs, copyin, check IPs. */ error = jail_handle_ips(j); if (error) return (error); /* Allocate struct prison and fill it with life. */ pr = malloc(sizeof(*pr), M_PRISON, M_WAITOK | M_ZERO); mtx_init(&pr->pr_mtx, "jail mutex", NULL, MTX_DEF); pr->pr_ref = 1; error = copyinstr(j->path, &pr->pr_path, sizeof(pr->pr_path), NULL); if (error) goto e_killmtx; NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKLEAF, UIO_SYSSPACE, pr->pr_path, td); error = namei(&nd); if (error) goto e_killmtx; vfslocked = NDHASGIANT(&nd); pr->pr_root = nd.ni_vp; VOP_UNLOCK(nd.ni_vp, 0); NDFREE(&nd, NDF_ONLY_PNBUF); VFS_UNLOCK_GIANT(vfslocked); error = copyinstr(j->hostname, &pr->pr_host, sizeof(pr->pr_host), NULL); if (error) goto e_dropvnref; if (j->jailname != NULL) { error = copyinstr(j->jailname, &pr->pr_name, sizeof(pr->pr_name), NULL); if (error) goto e_dropvnref; } if (j->ip4s > 0) { pr->pr_ip4 = j->ip4; pr->pr_ip4s = j->ip4s; } #ifdef INET6 if (j->ip6s > 0) { pr->pr_ip6 = j->ip6; pr->pr_ip6s = j->ip6s; } #endif pr->pr_linux = NULL; pr->pr_securelevel = securelevel; bzero(&pr->pr_osd, sizeof(pr->pr_osd)); /* * Pre-set prison state to ALIVE upon cration. This is needed so we * can later attach the process to it, etc (avoiding another extra * state for ther process of creation, complicating things). */ pr->pr_state = PRISON_STATE_ALIVE; /* Allocate a dedicated cpuset for each jail. */ error = cpuset_create_root(td, &pr->pr_cpuset); if (error) goto e_dropvnref; sx_xlock(&allprison_lock); /* Make sure we cannot run into problems with ambiguous bind()ings. */ #if defined(INET) || defined(INET6) error = prison_check_conflicting_ips(pr); if (error) { sx_xunlock(&allprison_lock); goto e_dropcpuset; } #endif /* Determine next pr_id and add prison to allprison list. */ tryprid = lastprid + 1; if (tryprid == JAIL_MAX) tryprid = 1; next: LIST_FOREACH(tpr, &allprison, pr_list) { if (tpr->pr_id == tryprid) { tryprid++; if (tryprid == JAIL_MAX) { sx_xunlock(&allprison_lock); error = EAGAIN; goto e_dropcpuset; } goto next; } } pr->pr_id = jaa.jid = lastprid = tryprid; LIST_INSERT_HEAD(&allprison, pr, pr_list); prisoncount++; sx_xunlock(&allprison_lock); error = jail_attach(td, &jaa); if (error) goto e_dropprref; mtx_lock(&pr->pr_mtx); pr->pr_ref--; mtx_unlock(&pr->pr_mtx); td->td_retval[0] = jaa.jid; return (0); e_dropprref: sx_xlock(&allprison_lock); LIST_REMOVE(pr, pr_list); prisoncount--; sx_xunlock(&allprison_lock); e_dropcpuset: cpuset_rel(pr->pr_cpuset); e_dropvnref: vfslocked = VFS_LOCK_GIANT(pr->pr_root->v_mount); vrele(pr->pr_root); VFS_UNLOCK_GIANT(vfslocked); e_killmtx: mtx_destroy(&pr->pr_mtx); free(pr, M_PRISON); #ifdef INET6 free(j->ip6, M_PRISON); #endif #ifdef INET free(j->ip4, M_PRISON); #endif return (error); } /* * struct jail_attach_args { * int jid; * }; */ int jail_attach(struct thread *td, struct jail_attach_args *uap) { struct proc *p; struct ucred *newcred, *oldcred; struct prison *pr; int vfslocked, error; /* * XXX: Note that there is a slight race here if two threads * in the same privileged process attempt to attach to two * different jails at the same time. It is important for * user processes not to do this, or they might end up with * a process root from one prison, but attached to the jail * of another. */ error = priv_check(td, PRIV_JAIL_ATTACH); if (error) return (error); p = td->td_proc; sx_slock(&allprison_lock); pr = prison_find(uap->jid); if (pr == NULL) { sx_sunlock(&allprison_lock); return (EINVAL); } /* * Do not allow a process to attach to a prison that is not * considered to be "ALIVE". */ if (pr->pr_state != PRISON_STATE_ALIVE) { mtx_unlock(&pr->pr_mtx); sx_sunlock(&allprison_lock); return (EINVAL); } pr->pr_ref++; mtx_unlock(&pr->pr_mtx); sx_sunlock(&allprison_lock); /* * Reparent the newly attached process to this jail. */ error = cpuset_setproc_update_set(p, pr->pr_cpuset); if (error) goto e_unref; vfslocked = VFS_LOCK_GIANT(pr->pr_root->v_mount); vn_lock(pr->pr_root, LK_EXCLUSIVE | LK_RETRY); if ((error = change_dir(pr->pr_root, td)) != 0) goto e_unlock; #ifdef MAC if ((error = mac_vnode_check_chroot(td->td_ucred, pr->pr_root))) goto e_unlock; #endif VOP_UNLOCK(pr->pr_root, 0); change_root(pr->pr_root, td); VFS_UNLOCK_GIANT(vfslocked); newcred = crget(); PROC_LOCK(p); oldcred = p->p_ucred; setsugid(p); crcopy(newcred, oldcred); newcred->cr_prison = pr; p->p_ucred = newcred; prison_proc_hold(pr); PROC_UNLOCK(p); crfree(oldcred); return (0); e_unlock: VOP_UNLOCK(pr->pr_root, 0); VFS_UNLOCK_GIANT(vfslocked); e_unref: mtx_lock(&pr->pr_mtx); pr->pr_ref--; mtx_unlock(&pr->pr_mtx); return (error); } /* * Returns a locked prison instance, or NULL on failure. */ struct prison * prison_find(int prid) { struct prison *pr; sx_assert(&allprison_lock, SX_LOCKED); LIST_FOREACH(pr, &allprison, pr_list) { if (pr->pr_id == prid) { mtx_lock(&pr->pr_mtx); if (pr->pr_ref == 0) { mtx_unlock(&pr->pr_mtx); break; } return (pr); } } return (NULL); } void prison_free_locked(struct prison *pr) { mtx_assert(&pr->pr_mtx, MA_OWNED); pr->pr_ref--; if (pr->pr_ref == 0) { mtx_unlock(&pr->pr_mtx); TASK_INIT(&pr->pr_task, 0, prison_complete, pr); taskqueue_enqueue(taskqueue_thread, &pr->pr_task); return; } mtx_unlock(&pr->pr_mtx); } void prison_free(struct prison *pr) { mtx_lock(&pr->pr_mtx); prison_free_locked(pr); } static void prison_complete(void *context, int pending) { struct prison *pr; int vfslocked; pr = (struct prison *)context; sx_xlock(&allprison_lock); LIST_REMOVE(pr, pr_list); prisoncount--; sx_xunlock(&allprison_lock); cpuset_rel(pr->pr_cpuset); /* Free all OSD associated to this jail. */ osd_jail_exit(pr); vfslocked = VFS_LOCK_GIANT(pr->pr_root->v_mount); vrele(pr->pr_root); VFS_UNLOCK_GIANT(vfslocked); mtx_destroy(&pr->pr_mtx); free(pr->pr_linux, M_PRISON); #ifdef INET6 free(pr->pr_ip6, M_PRISON); #endif #ifdef INET free(pr->pr_ip4, M_PRISON); #endif free(pr, M_PRISON); } void prison_hold_locked(struct prison *pr) { mtx_assert(&pr->pr_mtx, MA_OWNED); KASSERT(pr->pr_ref > 0, ("Trying to hold dead prison (id=%d).", pr->pr_id)); pr->pr_ref++; } void prison_hold(struct prison *pr) { mtx_lock(&pr->pr_mtx); prison_hold_locked(pr); mtx_unlock(&pr->pr_mtx); } void prison_proc_hold(struct prison *pr) { mtx_lock(&pr->pr_mtx); KASSERT(pr->pr_state == PRISON_STATE_ALIVE, ("Cannot add a process to a non-alive prison (id=%d).", pr->pr_id)); pr->pr_nprocs++; mtx_unlock(&pr->pr_mtx); } void prison_proc_free(struct prison *pr) { mtx_lock(&pr->pr_mtx); KASSERT(pr->pr_state == PRISON_STATE_ALIVE && pr->pr_nprocs > 0, ("Trying to kill a process in a dead prison (id=%d).", pr->pr_id)); pr->pr_nprocs--; if (pr->pr_nprocs == 0) pr->pr_state = PRISON_STATE_DYING; mtx_unlock(&pr->pr_mtx); } #ifdef INET /* * Pass back primary IPv4 address of this jail. * * If not jailed return success but do not alter the address. Caller has to * make sure to intialize it correctly (INADDR_ANY). * * Returns 0 on success, 1 on error. Address returned in NBO. */ int prison_getip4(struct ucred *cred, struct in_addr *ia) { KASSERT(cred != NULL, ("%s: cred is NULL", __func__)); KASSERT(ia != NULL, ("%s: ia is NULL", __func__)); if (!jailed(cred)) /* Do not change address passed in. */ return (0); if (cred->cr_prison->pr_ip4 == NULL) return (1); ia->s_addr = cred->cr_prison->pr_ip4[0].s_addr; return (0); } /* * Make sure our (source) address is set to something meaningful to this * jail. * * Returns 0 on success, 1 on error. Address passed in in NBO and returned * in NBO. */ int prison_local_ip4(struct ucred *cred, struct in_addr *ia) { struct in_addr ia0; KASSERT(cred != NULL, ("%s: cred is NULL", __func__)); KASSERT(ia != NULL, ("%s: ia is NULL", __func__)); if (!jailed(cred)) return (0); if (cred->cr_prison->pr_ip4 == NULL) return (1); ia0.s_addr = ntohl(ia->s_addr); if (ia0.s_addr == INADDR_LOOPBACK) { ia->s_addr = cred->cr_prison->pr_ip4[0].s_addr; return (0); } /* * In case there is only 1 IPv4 address, bind directly. */ if (ia0.s_addr == INADDR_ANY && cred->cr_prison->pr_ip4s == 1) { ia->s_addr = cred->cr_prison->pr_ip4[0].s_addr; return (0); } if (ia0.s_addr == INADDR_ANY || prison_check_ip4(cred, ia)) return (0); return (1); } /* * Rewrite destination address in case we will connect to loopback address. * * Returns 0 on success, 1 on error. Address passed in in NBO and returned * in NBO. */ int prison_remote_ip4(struct ucred *cred, struct in_addr *ia) { KASSERT(cred != NULL, ("%s: cred is NULL", __func__)); KASSERT(ia != NULL, ("%s: ia is NULL", __func__)); if (!jailed(cred)) return (0); if (cred->cr_prison->pr_ip4 == NULL) return (1); if (ntohl(ia->s_addr) == INADDR_LOOPBACK) { ia->s_addr = cred->cr_prison->pr_ip4[0].s_addr; return (0); } /* * Return success because nothing had to be changed. */ return (0); } /* * Check if given address belongs to the jail referenced by cred. * * Returns 1 if address belongs to jail, 0 if not. Address passed in in NBO. */ static int _prison_check_ip4(struct prison *pr, struct in_addr *ia) { int i, a, z, d; if (pr->pr_ip4 == NULL) return (0); /* * Check the primary IP. */ if (pr->pr_ip4[0].s_addr == ia->s_addr) return (1); /* * All the other IPs are sorted so we can do a binary search. */ a = 0; z = pr->pr_ip4s - 2; while (a <= z) { i = (a + z) / 2; d = qcmp_v4(&pr->pr_ip4[i+1], ia); if (d > 0) z = i - 1; else if (d < 0) a = i + 1; else return (1); } return (0); } int prison_check_ip4(struct ucred *cred, struct in_addr *ia) { KASSERT(cred != NULL, ("%s: cred is NULL", __func__)); KASSERT(ia != NULL, ("%s: ia is NULL", __func__)); if (!jailed(cred)) return (1); return (_prison_check_ip4(cred->cr_prison, ia)); } #endif #ifdef INET6 /* * Pass back primary IPv6 address for this jail. * * If not jailed return success but do not alter the address. Caller has to * make sure to intialize it correctly (IN6ADDR_ANY_INIT). * * Returns 0 on success, 1 on error. */ int prison_getip6(struct ucred *cred, struct in6_addr *ia6) { KASSERT(cred != NULL, ("%s: cred is NULL", __func__)); KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__)); if (!jailed(cred)) return (0); if (cred->cr_prison->pr_ip6 == NULL) return (1); bcopy(&cred->cr_prison->pr_ip6[0], ia6, sizeof(struct in6_addr)); return (0); } /* * Make sure our (source) address is set to something meaningful to this jail. * * v6only should be set based on (inp->inp_flags & IN6P_IPV6_V6ONLY != 0) * when needed while binding. * * Returns 0 on success, 1 on error. */ int prison_local_ip6(struct ucred *cred, struct in6_addr *ia6, int v6only) { KASSERT(cred != NULL, ("%s: cred is NULL", __func__)); KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__)); if (!jailed(cred)) return (0); if (cred->cr_prison->pr_ip6 == NULL) return (1); if (IN6_IS_ADDR_LOOPBACK(ia6)) { bcopy(&cred->cr_prison->pr_ip6[0], ia6, sizeof(struct in6_addr)); return (0); } /* * In case there is only 1 IPv6 address, and v6only is true, then * bind directly. */ if (v6only != 0 && IN6_IS_ADDR_UNSPECIFIED(ia6) && cred->cr_prison->pr_ip6s == 1) { bcopy(&cred->cr_prison->pr_ip6[0], ia6, sizeof(struct in6_addr)); return (0); } if (IN6_IS_ADDR_UNSPECIFIED(ia6) || prison_check_ip6(cred, ia6)) return (0); return (1); } /* * Rewrite destination address in case we will connect to loopback address. * * Returns 0 on success, 1 on error. */ int prison_remote_ip6(struct ucred *cred, struct in6_addr *ia6) { KASSERT(cred != NULL, ("%s: cred is NULL", __func__)); KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__)); if (!jailed(cred)) return (0); if (cred->cr_prison->pr_ip6 == NULL) return (1); if (IN6_IS_ADDR_LOOPBACK(ia6)) { bcopy(&cred->cr_prison->pr_ip6[0], ia6, sizeof(struct in6_addr)); return (0); } /* * Return success because nothing had to be changed. */ return (0); } /* * Check if given address belongs to the jail referenced by cred. * * Returns 1 if address belongs to jail, 0 if not. */ static int _prison_check_ip6(struct prison *pr, struct in6_addr *ia6) { int i, a, z, d; if (pr->pr_ip6 == NULL) return (0); /* * Check the primary IP. */ if (IN6_ARE_ADDR_EQUAL(&pr->pr_ip6[0], ia6)) return (1); /* * All the other IPs are sorted so we can do a binary search. */ a = 0; z = pr->pr_ip6s - 2; while (a <= z) { i = (a + z) / 2; d = qcmp_v6(&pr->pr_ip6[i+1], ia6); if (d > 0) z = i - 1; else if (d < 0) a = i + 1; else return (1); } return (0); } int prison_check_ip6(struct ucred *cred, struct in6_addr *ia6) { KASSERT(cred != NULL, ("%s: cred is NULL", __func__)); KASSERT(ia6 != NULL, ("%s: ia6 is NULL", __func__)); if (!jailed(cred)) return (1); return (_prison_check_ip6(cred->cr_prison, ia6)); } #endif /* * Check if given address belongs to the jail referenced by cred (wrapper to * prison_check_ip[46]). * * Returns 1 if address belongs to jail, 0 if not. IPv4 Address passed in in * NBO. */ int prison_if(struct ucred *cred, struct sockaddr *sa) { #ifdef INET struct sockaddr_in *sai; #endif #ifdef INET6 struct sockaddr_in6 *sai6; #endif int ok; KASSERT(cred != NULL, ("%s: cred is NULL", __func__)); KASSERT(sa != NULL, ("%s: sa is NULL", __func__)); ok = 0; switch(sa->sa_family) { #ifdef INET case AF_INET: sai = (struct sockaddr_in *)sa; if (prison_check_ip4(cred, &sai->sin_addr)) ok = 1; break; #endif #ifdef INET6 case AF_INET6: sai6 = (struct sockaddr_in6 *)sa; if (prison_check_ip6(cred, (struct in6_addr *)&sai6->sin6_addr)) ok = 1; break; #endif default: if (!jail_socket_unixiproute_only) ok = 1; } return (ok); } /* * Return 0 if jails permit p1 to frob p2, otherwise ESRCH. */ int prison_check(struct ucred *cred1, struct ucred *cred2) { if (jailed(cred1)) { if (!jailed(cred2)) return (ESRCH); if (cred2->cr_prison != cred1->cr_prison) return (ESRCH); } return (0); } /* * Return 1 if the passed credential is in a jail, otherwise 0. */ int jailed(struct ucred *cred) { return (cred->cr_prison != NULL); } /* * Return the correct hostname for the passed credential. */ void getcredhostname(struct ucred *cred, char *buf, size_t size) { INIT_VPROCG(cred->cr_vimage->v_procg); if (jailed(cred)) { mtx_lock(&cred->cr_prison->pr_mtx); strlcpy(buf, cred->cr_prison->pr_host, size); mtx_unlock(&cred->cr_prison->pr_mtx); } else { mtx_lock(&hostname_mtx); strlcpy(buf, V_hostname, size); mtx_unlock(&hostname_mtx); } } /* * Determine whether the subject represented by cred can "see" * status of a mount point. * Returns: 0 for permitted, ENOENT otherwise. * XXX: This function should be called cr_canseemount() and should be * placed in kern_prot.c. */ int prison_canseemount(struct ucred *cred, struct mount *mp) { struct prison *pr; struct statfs *sp; size_t len; if (!jailed(cred) || jail_enforce_statfs == 0) return (0); pr = cred->cr_prison; if (pr->pr_root->v_mount == mp) return (0); if (jail_enforce_statfs == 2) return (ENOENT); /* * If jail's chroot directory is set to "/" we should be able to see * all mount-points from inside a jail. * This is ugly check, but this is the only situation when jail's * directory ends with '/'. */ if (strcmp(pr->pr_path, "/") == 0) return (0); len = strlen(pr->pr_path); sp = &mp->mnt_stat; if (strncmp(pr->pr_path, sp->f_mntonname, len) != 0) return (ENOENT); /* * Be sure that we don't have situation where jail's root directory * is "/some/path" and mount point is "/some/pathpath". */ if (sp->f_mntonname[len] != '\0' && sp->f_mntonname[len] != '/') return (ENOENT); return (0); } void prison_enforce_statfs(struct ucred *cred, struct mount *mp, struct statfs *sp) { char jpath[MAXPATHLEN]; struct prison *pr; size_t len; if (!jailed(cred) || jail_enforce_statfs == 0) return; pr = cred->cr_prison; if (prison_canseemount(cred, mp) != 0) { bzero(sp->f_mntonname, sizeof(sp->f_mntonname)); strlcpy(sp->f_mntonname, "[restricted]", sizeof(sp->f_mntonname)); return; } if (pr->pr_root->v_mount == mp) { /* * Clear current buffer data, so we are sure nothing from * the valid path left there. */ bzero(sp->f_mntonname, sizeof(sp->f_mntonname)); *sp->f_mntonname = '/'; return; } /* * If jail's chroot directory is set to "/" we should be able to see * all mount-points from inside a jail. */ if (strcmp(pr->pr_path, "/") == 0) return; len = strlen(pr->pr_path); strlcpy(jpath, sp->f_mntonname + len, sizeof(jpath)); /* * Clear current buffer data, so we are sure nothing from * the valid path left there. */ bzero(sp->f_mntonname, sizeof(sp->f_mntonname)); if (*jpath == '\0') { /* Should never happen. */ *sp->f_mntonname = '/'; } else { strlcpy(sp->f_mntonname, jpath, sizeof(sp->f_mntonname)); } } /* * Check with permission for a specific privilege is granted within jail. We * have a specific list of accepted privileges; the rest are denied. */ int prison_priv_check(struct ucred *cred, int priv) { if (!jailed(cred)) return (0); switch (priv) { /* * Allow ktrace privileges for root in jail. */ case PRIV_KTRACE: #if 0 /* * Allow jailed processes to configure audit identity and * submit audit records (login, etc). In the future we may * want to further refine the relationship between audit and * jail. */ case PRIV_AUDIT_GETAUDIT: case PRIV_AUDIT_SETAUDIT: case PRIV_AUDIT_SUBMIT: #endif /* * Allow jailed processes to manipulate process UNIX * credentials in any way they see fit. */ case PRIV_CRED_SETUID: case PRIV_CRED_SETEUID: case PRIV_CRED_SETGID: case PRIV_CRED_SETEGID: case PRIV_CRED_SETGROUPS: case PRIV_CRED_SETREUID: case PRIV_CRED_SETREGID: case PRIV_CRED_SETRESUID: case PRIV_CRED_SETRESGID: /* * Jail implements visibility constraints already, so allow * jailed root to override uid/gid-based constraints. */ case PRIV_SEEOTHERGIDS: case PRIV_SEEOTHERUIDS: /* * Jail implements inter-process debugging limits already, so * allow jailed root various debugging privileges. */ case PRIV_DEBUG_DIFFCRED: case PRIV_DEBUG_SUGID: case PRIV_DEBUG_UNPRIV: /* * Allow jail to set various resource limits and login * properties, and for now, exceed process resource limits. */ case PRIV_PROC_LIMIT: case PRIV_PROC_SETLOGIN: case PRIV_PROC_SETRLIMIT: /* * System V and POSIX IPC privileges are granted in jail. */ case PRIV_IPC_READ: case PRIV_IPC_WRITE: case PRIV_IPC_ADMIN: case PRIV_IPC_MSGSIZE: case PRIV_MQ_ADMIN: /* * Jail implements its own inter-process limits, so allow * root processes in jail to change scheduling on other * processes in the same jail. Likewise for signalling. */ case PRIV_SCHED_DIFFCRED: case PRIV_SCHED_CPUSET: case PRIV_SIGNAL_DIFFCRED: case PRIV_SIGNAL_SUGID: /* * Allow jailed processes to write to sysctls marked as jail * writable. */ case PRIV_SYSCTL_WRITEJAIL: /* * Allow root in jail to manage a variety of quota * properties. These should likely be conditional on a * configuration option. */ case PRIV_VFS_GETQUOTA: case PRIV_VFS_SETQUOTA: /* * Since Jail relies on chroot() to implement file system * protections, grant many VFS privileges to root in jail. * Be careful to exclude mount-related and NFS-related * privileges. */ case PRIV_VFS_READ: case PRIV_VFS_WRITE: case PRIV_VFS_ADMIN: case PRIV_VFS_EXEC: case PRIV_VFS_LOOKUP: case PRIV_VFS_BLOCKRESERVE: /* XXXRW: Slightly surprising. */ case PRIV_VFS_CHFLAGS_DEV: case PRIV_VFS_CHOWN: case PRIV_VFS_CHROOT: case PRIV_VFS_RETAINSUGID: case PRIV_VFS_FCHROOT: case PRIV_VFS_LINK: case PRIV_VFS_SETGID: case PRIV_VFS_STAT: case PRIV_VFS_STICKYFILE: return (0); /* * Depending on the global setting, allow privilege of * setting system flags. */ case PRIV_VFS_SYSFLAGS: if (jail_chflags_allowed) return (0); else return (EPERM); /* * Depending on the global setting, allow privilege of * mounting/unmounting file systems. */ case PRIV_VFS_MOUNT: case PRIV_VFS_UNMOUNT: case PRIV_VFS_MOUNT_NONUSER: case PRIV_VFS_MOUNT_OWNER: if (jail_mount_allowed) return (0); else return (EPERM); /* * Allow jailed root to bind reserved ports and reuse in-use * ports. */ case PRIV_NETINET_RESERVEDPORT: case PRIV_NETINET_REUSEPORT: return (0); /* * Allow jailed root to set certian IPv4/6 (option) headers. */ case PRIV_NETINET_SETHDROPTS: return (0); /* * Conditionally allow creating raw sockets in jail. */ case PRIV_NETINET_RAW: if (jail_allow_raw_sockets) return (0); else return (EPERM); /* * Since jail implements its own visibility limits on netstat * sysctls, allow getcred. This allows identd to work in * jail. */ case PRIV_NETINET_GETCRED: return (0); default: /* * In all remaining cases, deny the privilege request. This * includes almost all network privileges, many system * configuration privileges. */ return (EPERM); } } static int sysctl_jail_list(SYSCTL_HANDLER_ARGS) { struct xprison *xp, *sxp; struct prison *pr; char *p; size_t len; int count, error; if (jailed(req->td->td_ucred)) return (0); sx_slock(&allprison_lock); if ((count = prisoncount) == 0) { sx_sunlock(&allprison_lock); return (0); } len = sizeof(*xp) * count; LIST_FOREACH(pr, &allprison, pr_list) { #ifdef INET len += pr->pr_ip4s * sizeof(struct in_addr); #endif #ifdef INET6 len += pr->pr_ip6s * sizeof(struct in6_addr); #endif } sxp = xp = malloc(len, M_TEMP, M_WAITOK | M_ZERO); LIST_FOREACH(pr, &allprison, pr_list) { xp->pr_version = XPRISON_VERSION; xp->pr_id = pr->pr_id; xp->pr_state = pr->pr_state; xp->pr_cpusetid = pr->pr_cpuset->cs_id; strlcpy(xp->pr_path, pr->pr_path, sizeof(xp->pr_path)); mtx_lock(&pr->pr_mtx); strlcpy(xp->pr_host, pr->pr_host, sizeof(xp->pr_host)); strlcpy(xp->pr_name, pr->pr_name, sizeof(xp->pr_name)); mtx_unlock(&pr->pr_mtx); #ifdef INET xp->pr_ip4s = pr->pr_ip4s; #endif #ifdef INET6 xp->pr_ip6s = pr->pr_ip6s; #endif p = (char *)(xp + 1); #ifdef INET if (pr->pr_ip4s > 0) { bcopy(pr->pr_ip4, (struct in_addr *)p, pr->pr_ip4s * sizeof(struct in_addr)); p += (pr->pr_ip4s * sizeof(struct in_addr)); } #endif #ifdef INET6 if (pr->pr_ip6s > 0) { bcopy(pr->pr_ip6, (struct in6_addr *)p, pr->pr_ip6s * sizeof(struct in6_addr)); p += (pr->pr_ip6s * sizeof(struct in6_addr)); } #endif xp = (struct xprison *)p; } sx_sunlock(&allprison_lock); error = SYSCTL_OUT(req, sxp, len); free(sxp, M_TEMP); return (error); } SYSCTL_OID(_security_jail, OID_AUTO, list, CTLTYPE_STRUCT | CTLFLAG_RD, NULL, 0, sysctl_jail_list, "S", "List of active jails"); static int sysctl_jail_jailed(SYSCTL_HANDLER_ARGS) { int error, injail; injail = jailed(req->td->td_ucred); error = SYSCTL_OUT(req, &injail, sizeof(injail)); return (error); } SYSCTL_PROC(_security_jail, OID_AUTO, jailed, CTLTYPE_INT | CTLFLAG_RD, NULL, 0, sysctl_jail_jailed, "I", "Process in jail?"); #ifdef DDB DB_SHOW_COMMAND(jails, db_show_jails) { struct prison *pr; #ifdef INET struct in_addr ia; #endif #ifdef INET6 char ip6buf[INET6_ADDRSTRLEN]; #endif const char *state; #if defined(INET) || defined(INET6) int i; #endif db_printf( " JID pr_ref pr_nprocs pr_ip4s pr_ip6s\n"); db_printf( " Hostname Path\n"); db_printf( " Name State\n"); db_printf( " Cpusetid\n"); db_printf( " IP Address(es)\n"); LIST_FOREACH(pr, &allprison, pr_list) { db_printf("%6d %6d %9d %7d %7d\n", pr->pr_id, pr->pr_ref, pr->pr_nprocs, pr->pr_ip4s, pr->pr_ip6s); db_printf("%6s %-29.29s %.74s\n", "", pr->pr_host, pr->pr_path); if (pr->pr_state < 0 || pr->pr_state >= (int)((sizeof( prison_states) / sizeof(struct prison_state)))) state = "(bogus)"; else state = prison_states[pr->pr_state].state_name; db_printf("%6s %-29.29s %.74s\n", "", (pr->pr_name[0] != '\0') ? pr->pr_name : "", state); db_printf("%6s %-6d\n", "", pr->pr_cpuset->cs_id); #ifdef INET for (i=0; i < pr->pr_ip4s; i++) { ia.s_addr = pr->pr_ip4[i].s_addr; db_printf("%6s %s\n", "", inet_ntoa(ia)); } #endif #ifdef INET6 for (i=0; i < pr->pr_ip6s; i++) db_printf("%6s %s\n", "", ip6_sprintf(ip6buf, &pr->pr_ip6[i])); #endif /* INET6 */ if (db_pager_quit) break; } } #endif /* DDB */