/* * ---------------------------------------------------------------------------- * "THE BEER-WARE LICENSE" (Revision 42): * wrote this file. As long as you retain this notice you * can do whatever you want with this stuff. If we meet some day, and you think * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp * ---------------------------------------------------------------------------- * */ /*- * Copyright (c) 2006 Victor Balada Diaz * 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. */ /* * $FreeBSD: src/sys/kern/kern_jail.c,v 1.6.2.3 2001/08/17 01:00:26 rwatson Exp $ * $DragonFly: src/sys/kern/kern_jail.c,v 1.19 2008/05/17 18:20:33 dillon Exp $ */ #include "opt_inet6.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static struct prison *prison_find(int); static void prison_ipcache_init(struct prison *); MALLOC_DEFINE(M_PRISON, "prison", "Prison structures"); SYSCTL_NODE(, OID_AUTO, jail, CTLFLAG_RW, 0, "Jail rules"); int jail_set_hostname_allowed = 1; SYSCTL_INT(_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(_jail, OID_AUTO, socket_unixiproute_only, CTLFLAG_RW, &jail_socket_unixiproute_only, 0, "Processes in jail are limited to creating UNIX/IPv[46]/route sockets only"); int jail_sysvipc_allowed = 0; SYSCTL_INT(_jail, OID_AUTO, sysvipc_allowed, CTLFLAG_RW, &jail_sysvipc_allowed, 0, "Processes in jail can use System V IPC primitives"); int jail_chflags_allowed = 0; SYSCTL_INT(_jail, OID_AUTO, chflags_allowed, CTLFLAG_RW, &jail_chflags_allowed, 0, "Process in jail can set chflags(1)"); int jail_allow_raw_sockets = 0; SYSCTL_INT(_jail, OID_AUTO, allow_raw_sockets, CTLFLAG_RW, &jail_allow_raw_sockets, 0, "Process in jail can create raw sockets"); int lastprid = 0; int prisoncount = 0; LIST_HEAD(prisonlist, prison); struct prisonlist allprison = LIST_HEAD_INITIALIZER(&allprison); static int kern_jail_attach(int jid) { struct proc *p = curthread->td_proc; struct prison *pr; int error; pr = prison_find(jid); if (pr == NULL) return(EINVAL); error = kern_chroot(&pr->pr_root); if (error) return(error); prison_hold(pr); cratom(&p->p_ucred); p->p_ucred->cr_prison = pr; p->p_flag |= P_JAILED; return(0); } static int assign_prison_id(struct prison *pr) { int tryprid; struct prison *tpr; tryprid = lastprid + 1; if (tryprid == JAIL_MAX) tryprid = 1; next: LIST_FOREACH(tpr, &allprison, pr_list) { if (tpr->pr_id != tryprid) continue; tryprid++; if (tryprid == JAIL_MAX) { return (ERANGE); } goto next; } pr->pr_id = lastprid = tryprid; return (0); } static int kern_jail(struct prison *pr, struct jail *j) { int error; struct nlookupdata nd; error = nlookup_init(&nd, j->path, UIO_USERSPACE, NLC_FOLLOW); if (error) { nlookup_done(&nd); return (error); } error = nlookup(&nd); if (error) { nlookup_done(&nd); return (error); } cache_copy(&nd.nl_nch, &pr->pr_root); varsymset_init(&pr->pr_varsymset, NULL); prison_ipcache_init(pr); error = assign_prison_id(pr); if (error) { varsymset_clean(&pr->pr_varsymset); nlookup_done(&nd); return (error); } LIST_INSERT_HEAD(&allprison, pr, pr_list); atomic_add_int(&prisoncount, 1); error = kern_jail_attach(pr->pr_id); if (error) { LIST_REMOVE(pr, pr_list); varsymset_clean(&pr->pr_varsymset); } nlookup_done(&nd); return (error); } /* * jail() * * jail_args(syscallarg(struct jail *) jail) * * MPALMOSTSAFE */ int sys_jail(struct jail_args *uap) { struct thread *td = curthread; struct prison *pr; struct jail_ip_storage *jip; struct jail j; int error; uint32_t jversion; uap->sysmsg_result = -1; error = priv_check(td, PRIV_JAIL_CREATE); if (error) return (error); error = copyin(uap->jail, &jversion, sizeof(jversion)); if (error) return (error); pr = kmalloc(sizeof(*pr), M_PRISON, M_WAITOK | M_ZERO); SLIST_INIT(&pr->pr_ips); get_mplock(); switch (jversion) { case 0: /* Single IPv4 jails. */ { struct jail_v0 jv0; struct sockaddr_in ip4addr; error = copyin(uap->jail, &jv0, sizeof(jv0)); if (error) goto out; j.path = jv0.path; j.hostname = jv0.hostname; jip = kmalloc(sizeof(*jip), M_PRISON, M_WAITOK | M_ZERO); ip4addr.sin_family = AF_INET; ip4addr.sin_addr.s_addr = htonl(jv0.ip_number); memcpy(&jip->ip, &ip4addr, sizeof(ip4addr)); SLIST_INSERT_HEAD(&pr->pr_ips, jip, entries); break; } case 1: /* * DragonFly multi noIP/IPv4/IPv6 jails * * NOTE: This version is unsupported by FreeBSD * (which uses version 2 instead). */ error = copyin(uap->jail, &j, sizeof(j)); if (error) goto out; for (int i = 0; i < j.n_ips; i++) { jip = kmalloc(sizeof(*jip), M_PRISON, M_WAITOK | M_ZERO); SLIST_INSERT_HEAD(&pr->pr_ips, jip, entries); error = copyin(&j.ips[i], &jip->ip, sizeof(struct sockaddr_storage)); if (error) goto out; } break; default: error = EINVAL; goto out; } error = copyinstr(j.hostname, &pr->pr_host, sizeof(pr->pr_host), 0); if (error) goto out; error = kern_jail(pr, &j); if (error) goto out; uap->sysmsg_result = pr->pr_id; rel_mplock(); return (0); out: /* Delete all ips */ while (!SLIST_EMPTY(&pr->pr_ips)) { jip = SLIST_FIRST(&pr->pr_ips); SLIST_REMOVE_HEAD(&pr->pr_ips, entries); kfree(jip, M_PRISON); } rel_mplock(); kfree(pr, M_PRISON); return (error); } /* * int jail_attach(int jid); * * MPALMOSTSAFE */ int sys_jail_attach(struct jail_attach_args *uap) { struct thread *td = curthread; int error; error = priv_check(td, PRIV_JAIL_ATTACH); if (error) return(error); get_mplock(); error = kern_jail_attach(uap->jid); rel_mplock(); return (error); } static void prison_ipcache_init(struct prison *pr) { struct jail_ip_storage *jis; struct sockaddr_in *ip4; struct sockaddr_in6 *ip6; SLIST_FOREACH(jis, &pr->pr_ips, entries) { switch (jis->ip.ss_family) { case AF_INET: ip4 = (struct sockaddr_in *)&jis->ip; if ((ntohl(ip4->sin_addr.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) { /* loopback address */ if (pr->local_ip4 == NULL) pr->local_ip4 = ip4; } else { /* public address */ if (pr->nonlocal_ip4 == NULL) pr->nonlocal_ip4 = ip4; } break; case AF_INET6: ip6 = (struct sockaddr_in6 *)&jis->ip; if (IN6_IS_ADDR_LOOPBACK(&ip6->sin6_addr)) { /* loopback address */ if (pr->local_ip6 == NULL) pr->local_ip6 = ip6; } else { /* public address */ if (pr->nonlocal_ip6 == NULL) pr->nonlocal_ip6 = ip6; } break; } } } /* * Changes INADDR_LOOPBACK for a valid jail address. * ip is in network byte order. * Returns 1 if the ip is among jail valid ips. * Returns 0 if is not among jail valid ips or * if couldn't replace INADDR_LOOPBACK for a valid * IP. */ int prison_replace_wildcards(struct thread *td, struct sockaddr *ip) { struct sockaddr_in *ip4 = (struct sockaddr_in *)ip; struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)ip; struct prison *pr; if (td->td_proc == NULL) return (1); if ((pr = td->td_ucred->cr_prison) == NULL) return (1); if ((ip->sa_family == AF_INET && ip4->sin_addr.s_addr == htonl(INADDR_ANY)) || (ip->sa_family == AF_INET6 && IN6_IS_ADDR_UNSPECIFIED(&ip6->sin6_addr))) return (1); if ((ip->sa_family == AF_INET && ip4->sin_addr.s_addr == htonl(INADDR_LOOPBACK)) || (ip->sa_family == AF_INET6 && IN6_IS_ADDR_LOOPBACK(&ip6->sin6_addr))) { if (!prison_get_local(pr, ip->sa_family, ip) && !prison_get_nonlocal(pr, ip->sa_family, ip)) return(0); else return(1); } if (jailed_ip(pr, ip)) return(1); return(0); } int prison_remote_ip(struct thread *td, struct sockaddr *ip) { struct sockaddr_in *ip4 = (struct sockaddr_in *)ip; struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)ip; struct prison *pr; if (td == NULL || td->td_proc == NULL) return(1); if ((pr = td->td_ucred->cr_prison) == NULL) return(1); if ((ip->sa_family == AF_INET && ip4->sin_addr.s_addr == htonl(INADDR_LOOPBACK)) || (ip->sa_family == AF_INET6 && IN6_IS_ADDR_LOOPBACK(&ip6->sin6_addr))) { if (!prison_get_local(pr, ip->sa_family, ip) && !prison_get_nonlocal(pr, ip->sa_family, ip)) return(0); else return(1); } return(1); } /* * Prison get non loopback ip: * - af is the address family of the ip we want (AF_INET|AF_INET6). * - If ip != NULL, put the first IP address that is not a loopback address * into *ip. * * ip is in network by order and we don't touch it unless we find a valid ip. * No matter if ip == NULL or not, we return either a valid struct sockaddr *, * or NULL. This struct may not be modified. */ struct sockaddr * prison_get_nonlocal(struct prison *pr, sa_family_t af, struct sockaddr *ip) { struct sockaddr_in *ip4 = (struct sockaddr_in *)ip; struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)ip; /* Check if it is cached */ switch(af) { case AF_INET: if (ip4 != NULL && pr->nonlocal_ip4 != NULL) ip4->sin_addr.s_addr = pr->nonlocal_ip4->sin_addr.s_addr; return (struct sockaddr *)pr->nonlocal_ip4; case AF_INET6: if (ip6 != NULL && pr->nonlocal_ip6 != NULL) ip6->sin6_addr = pr->nonlocal_ip6->sin6_addr; return (struct sockaddr *)pr->nonlocal_ip6; } /* NOTREACHED */ return NULL; } /* * Prison get loopback ip. * - af is the address family of the ip we want (AF_INET|AF_INET6). * - If ip != NULL, put the first IP address that is not a loopback address * into *ip. * * ip is in network by order and we don't touch it unless we find a valid ip. * No matter if ip == NULL or not, we return either a valid struct sockaddr *, * or NULL. This struct may not be modified. */ struct sockaddr * prison_get_local(struct prison *pr, sa_family_t af, struct sockaddr *ip) { struct sockaddr_in *ip4 = (struct sockaddr_in *)ip; struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)ip; /* Check if it is cached */ switch(af) { case AF_INET: if (ip4 != NULL && pr->local_ip4 != NULL) ip4->sin_addr.s_addr = pr->local_ip4->sin_addr.s_addr; return (struct sockaddr *)pr->local_ip4; case AF_INET6: if (ip6 != NULL && pr->local_ip6 != NULL) ip6->sin6_addr = pr->local_ip6->sin6_addr; return (struct sockaddr *)pr->local_ip6; } /* NOTREACHED */ return NULL; } /* Check if the IP is among ours, if it is return 1, else 0 */ int jailed_ip(struct prison *pr, struct sockaddr *ip) { struct jail_ip_storage *jis; struct sockaddr_in *jip4, *ip4; struct sockaddr_in6 *jip6, *ip6; if (pr == NULL) return(0); ip4 = (struct sockaddr_in *)ip; ip6 = (struct sockaddr_in6 *)ip; SLIST_FOREACH(jis, &pr->pr_ips, entries) { switch (ip->sa_family) { case AF_INET: jip4 = (struct sockaddr_in *) &jis->ip; if (jip4->sin_family == AF_INET && ip4->sin_addr.s_addr == jip4->sin_addr.s_addr) return(1); break; case AF_INET6: jip6 = (struct sockaddr_in6 *) &jis->ip; if (jip6->sin6_family == AF_INET6 && IN6_ARE_ADDR_EQUAL(&ip6->sin6_addr, &jip6->sin6_addr)) return(1); break; } } /* Ip not in list */ return(0); } int prison_if(struct ucred *cred, struct sockaddr *sa) { struct prison *pr; struct sockaddr_in *sai = (struct sockaddr_in*) sa; pr = cred->cr_prison; if (((sai->sin_family != AF_INET) && (sai->sin_family != AF_INET6)) && jail_socket_unixiproute_only) return(1); else if ((sai->sin_family != AF_INET) && (sai->sin_family != AF_INET6)) return(0); else if (jailed_ip(pr, sa)) return(0); return(1); } /* * Returns a prison instance, or NULL on failure. */ static struct prison * prison_find(int prid) { struct prison *pr; LIST_FOREACH(pr, &allprison, pr_list) { if (pr->pr_id == prid) break; } return(pr); } static int sysctl_jail_list(SYSCTL_HANDLER_ARGS) { struct thread *td = curthread; struct jail_ip_storage *jip; #ifdef INET6 struct sockaddr_in6 *jsin6; #endif struct sockaddr_in *jsin; struct lwp *lp; struct prison *pr; unsigned int jlssize, jlsused; int count, error; char *jls; /* Jail list */ char *oip; /* Output ip */ char *fullpath, *freepath; jlsused = 0; if (jailed(td->td_ucred)) return (0); lp = td->td_lwp; retry: count = prisoncount; if (count == 0) return(0); jlssize = (count * 1024); jls = kmalloc(jlssize + 1, M_TEMP, M_WAITOK | M_ZERO); if (count < prisoncount) { kfree(jls, M_TEMP); goto retry; } count = prisoncount; LIST_FOREACH(pr, &allprison, pr_list) { error = cache_fullpath(lp->lwp_proc, &pr->pr_root, &fullpath, &freepath); if (error) continue; if (jlsused && jlsused < jlssize) jls[jlsused++] = '\n'; count = ksnprintf(jls + jlsused, (jlssize - jlsused), "%d %s %s", pr->pr_id, pr->pr_host, fullpath); kfree(freepath, M_TEMP); if (count < 0) goto end; jlsused += count; /* Copy the IPS */ SLIST_FOREACH(jip, &pr->pr_ips, entries) { jsin = (struct sockaddr_in *)&jip->ip; switch(jsin->sin_family) { case AF_INET: oip = inet_ntoa(jsin->sin_addr); break; #ifdef INET6 case AF_INET6: jsin6 = (struct sockaddr_in6 *)&jip->ip; oip = ip6_sprintf(&jsin6->sin6_addr); break; #endif default: oip = "?family?"; break; } if ((jlssize - jlsused) < (strlen(oip) + 1)) { error = ERANGE; goto end; } count = ksnprintf(jls + jlsused, (jlssize - jlsused), " %s", oip); if (count < 0) goto end; jlsused += count; } } /* * The format is: * pr_id hostname1 PATH1 IP1 IP2\npr_id... */ error = SYSCTL_OUT(req, jls, jlsused); end: kfree(jls, M_TEMP); return(error); } SYSCTL_OID(_jail, OID_AUTO, list, CTLTYPE_STRING | CTLFLAG_RD, NULL, 0, sysctl_jail_list, "A", "List of active jails"); /* * MPSAFE */ void prison_hold(struct prison *pr) { atomic_add_int(&pr->pr_ref, 1); } /* * MPALMOSTSAFE */ void prison_free(struct prison *pr) { struct jail_ip_storage *jls; KKASSERT(pr->pr_ref > 0); if (atomic_fetchadd_int(&pr->pr_ref, -1) != 1) return; /* * The MP lock is needed on the last ref to adjust * the list. */ get_mplock(); if (pr->pr_ref) { rel_mplock(); return; } LIST_REMOVE(pr, pr_list); atomic_add_int(&prisoncount, -1); rel_mplock(); /* * Clean up */ while (!SLIST_EMPTY(&pr->pr_ips)) { jls = SLIST_FIRST(&pr->pr_ips); SLIST_REMOVE_HEAD(&pr->pr_ips, entries); kfree(jls, M_PRISON); } if (pr->pr_linux != NULL) kfree(pr->pr_linux, M_PRISON); varsymset_clean(&pr->pr_varsymset); cache_drop(&pr->pr_root); kfree(pr, M_PRISON); } /* * Check if permisson for a specific privilege is granted within jail. * * MPSAFE */ int prison_priv_check(struct ucred *cred, int priv) { if (!jailed(cred)) return (0); switch (priv) { 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: case PRIV_VFS_SYSFLAGS: case PRIV_VFS_CHOWN: case PRIV_VFS_CHMOD: case PRIV_VFS_CHROOT: case PRIV_VFS_LINK: case PRIV_VFS_CHFLAGS_DEV: case PRIV_VFS_REVOKE: case PRIV_VFS_MKNOD_BAD: case PRIV_VFS_MKNOD_WHT: case PRIV_VFS_MKNOD_DIR: case PRIV_VFS_SETATTR: case PRIV_VFS_SETGID: case PRIV_PROC_SETRLIMIT: case PRIV_PROC_SETLOGIN: case PRIV_SYSCTL_WRITEJAIL: case PRIV_VARSYM_SYS: case PRIV_SETHOSTNAME: case PRIV_PROC_TRESPASS: return (0); case PRIV_UFS_QUOTAON: case PRIV_UFS_QUOTAOFF: case PRIV_VFS_SETQUOTA: case PRIV_UFS_SETUSE: case PRIV_VFS_GETQUOTA: return (0); case PRIV_DEBUG_UNPRIV: return (0); /* * Allow jailed root to bind reserved ports. */ case PRIV_NETINET_RESERVEDPORT: return (0); /* * Conditionally allow creating raw sockets in jail. */ case PRIV_NETINET_RAW: if (jail_allow_raw_sockets) return (0); else return (EPERM); case PRIV_HAMMER_IOCTL: return (0); default: return (EPERM); } }