/* Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "ap_config.h" #include "httpd.h" #include "http_config.h" #include "http_main.h" #include "http_log.h" #include "unixd.h" #include "mpm_common.h" #include "os.h" #include "ap_mpm.h" #include "apr_thread_proc.h" #include "apr_strings.h" #include "apr_portable.h" #ifdef HAVE_PWD_H #include #endif #ifdef HAVE_SYS_RESOURCE_H #include #endif /* XXX */ #include #ifdef HAVE_UNISTD_H #include #endif #ifdef HAVE_GRP_H #include #endif #ifdef HAVE_STRINGS_H #include #endif #ifdef HAVE_SYS_SEM_H #include #endif #ifdef HAVE_SYS_PRCTL_H #include #endif unixd_config_rec ap_unixd_config; APLOG_USE_MODULE(core); AP_DECLARE(void) ap_unixd_set_rlimit(cmd_parms *cmd, struct rlimit **plimit, const char *arg, const char * arg2, int type) { #if (defined(RLIMIT_CPU) || defined(RLIMIT_DATA) || defined(RLIMIT_VMEM) || defined(RLIMIT_NPROC) || defined(RLIMIT_AS)) && APR_HAVE_STRUCT_RLIMIT && APR_HAVE_GETRLIMIT char *str; struct rlimit *limit; /* If your platform doesn't define rlim_t then typedef it in ap_config.h */ rlim_t cur = 0; rlim_t max = 0; *plimit = (struct rlimit *)apr_pcalloc(cmd->pool, sizeof(**plimit)); limit = *plimit; if ((getrlimit(type, limit)) != 0) { *plimit = NULL; ap_log_error(APLOG_MARK, APLOG_ERR, errno, cmd->server, "%s: getrlimit failed", cmd->cmd->name); return; } if ((str = ap_getword_conf(cmd->pool, &arg))) { if (!strcasecmp(str, "max")) { cur = limit->rlim_max; } else { cur = atol(str); } } else { ap_log_error(APLOG_MARK, APLOG_ERR, 0, cmd->server, "Invalid parameters for %s", cmd->cmd->name); return; } if (arg2 && (str = ap_getword_conf(cmd->pool, &arg2))) { max = atol(str); } /* if we aren't running as root, cannot increase max */ if (geteuid()) { limit->rlim_cur = cur; if (max && (max > limit->rlim_max)) { ap_log_error(APLOG_MARK, APLOG_ERR, 0, cmd->server, "Must be uid 0 to raise maximum %s", cmd->cmd->name); } else if (max) { limit->rlim_max = max; } } else { if (cur) { limit->rlim_cur = cur; } if (max) { limit->rlim_max = max; } } #else ap_log_error(APLOG_MARK, APLOG_ERR, 0, cmd->server, "Platform does not support rlimit for %s", cmd->cmd->name); #endif } APR_HOOK_STRUCT( APR_HOOK_LINK(get_suexec_identity) ) AP_IMPLEMENT_HOOK_RUN_FIRST(ap_unix_identity_t *, get_suexec_identity, (const request_rec *r), (r), NULL) static apr_status_t ap_unix_create_privileged_process( apr_proc_t *newproc, const char *progname, const char * const *args, const char * const *env, apr_procattr_t *attr, ap_unix_identity_t *ugid, apr_pool_t *p) { int i = 0; const char **newargs; char *newprogname; char *execuser, *execgroup; const char *argv0; if (!ap_unixd_config.suexec_enabled) { return apr_proc_create(newproc, progname, args, env, attr, p); } argv0 = ap_strrchr_c(progname, '/'); /* Allow suexec's "/" check to succeed */ if (argv0 != NULL) { argv0++; } else { argv0 = progname; } if (ugid->userdir) { execuser = apr_psprintf(p, "~%ld", (long) ugid->uid); } else { execuser = apr_psprintf(p, "%ld", (long) ugid->uid); } execgroup = apr_psprintf(p, "%ld", (long) ugid->gid); if (!execuser || !execgroup) { return APR_ENOMEM; } i = 0; if (args) { while (args[i]) { i++; } } /* allocate space for 4 new args, the input args, and a null terminator */ newargs = apr_palloc(p, sizeof(char *) * (i + 4)); newprogname = SUEXEC_BIN; newargs[0] = SUEXEC_BIN; newargs[1] = execuser; newargs[2] = execgroup; newargs[3] = apr_pstrdup(p, argv0); /* ** using a shell to execute suexec makes no sense thus ** we force everything to be APR_PROGRAM, and never ** APR_SHELLCMD */ if(apr_procattr_cmdtype_set(attr, APR_PROGRAM) != APR_SUCCESS) { return APR_EGENERAL; } i = 1; do { newargs[i + 3] = args[i]; } while (args[i++]); return apr_proc_create(newproc, newprogname, newargs, env, attr, p); } AP_DECLARE(apr_status_t) ap_os_create_privileged_process( const request_rec *r, apr_proc_t *newproc, const char *progname, const char * const *args, const char * const *env, apr_procattr_t *attr, apr_pool_t *p) { ap_unix_identity_t *ugid = ap_run_get_suexec_identity(r); if (ugid == NULL) { return apr_proc_create(newproc, progname, args, env, attr, p); } return ap_unix_create_privileged_process(newproc, progname, args, env, attr, ugid, p); } /* XXX move to APR and externalize (but implement differently :) ) */ static apr_lockmech_e proc_mutex_mech(apr_proc_mutex_t *pmutex) { const char *mechname = apr_proc_mutex_name(pmutex); if (!strcmp(mechname, "sysvsem")) { return APR_LOCK_SYSVSEM; } else if (!strcmp(mechname, "flock")) { return APR_LOCK_FLOCK; } return APR_LOCK_DEFAULT; } AP_DECLARE(apr_status_t) ap_unixd_set_proc_mutex_perms(apr_proc_mutex_t *pmutex) { if (!geteuid()) { apr_lockmech_e mech = proc_mutex_mech(pmutex); switch(mech) { #if APR_HAS_SYSVSEM_SERIALIZE case APR_LOCK_SYSVSEM: { apr_os_proc_mutex_t ospmutex; #if !APR_HAVE_UNION_SEMUN union semun { long val; struct semid_ds *buf; unsigned short *array; }; #endif union semun ick; struct semid_ds buf; apr_os_proc_mutex_get(&ospmutex, pmutex); buf.sem_perm.uid = ap_unixd_config.user_id; buf.sem_perm.gid = ap_unixd_config.group_id; buf.sem_perm.mode = 0600; ick.buf = &buf; if (semctl(ospmutex.crossproc, 0, IPC_SET, ick) < 0) { return errno; } } break; #endif #if APR_HAS_FLOCK_SERIALIZE case APR_LOCK_FLOCK: { const char *lockfile = apr_proc_mutex_lockfile(pmutex); if (lockfile) { if (chown(lockfile, ap_unixd_config.user_id, -1 /* no gid change */) < 0) { return errno; } } } break; #endif default: /* do nothing */ break; } } return APR_SUCCESS; } AP_DECLARE(apr_status_t) ap_unixd_set_global_mutex_perms(apr_global_mutex_t *gmutex) { #if !APR_PROC_MUTEX_IS_GLOBAL apr_os_global_mutex_t osgmutex; apr_os_global_mutex_get(&osgmutex, gmutex); return ap_unixd_set_proc_mutex_perms(osgmutex.proc_mutex); #else /* APR_PROC_MUTEX_IS_GLOBAL */ /* In this case, apr_proc_mutex_t and apr_global_mutex_t are the same. */ return ap_unixd_set_proc_mutex_perms(gmutex); #endif /* APR_PROC_MUTEX_IS_GLOBAL */ } AP_DECLARE(apr_status_t) ap_unixd_accept(void **accepted, ap_listen_rec *lr, apr_pool_t *ptrans) { apr_socket_t *csd; apr_status_t status; #ifdef _OSD_POSIX int sockdes; #endif *accepted = NULL; status = apr_socket_accept(&csd, lr->sd, ptrans); if (status == APR_SUCCESS) { *accepted = csd; #ifdef _OSD_POSIX apr_os_sock_get(&sockdes, csd); if (sockdes >= FD_SETSIZE) { ap_log_error(APLOG_MARK, APLOG_WARNING, 0, ap_server_conf, "new file descriptor %d is too large; you probably need " "to rebuild Apache with a larger FD_SETSIZE " "(currently %d)", sockdes, FD_SETSIZE); apr_socket_close(csd); return APR_EINTR; } #endif return APR_SUCCESS; } if (APR_STATUS_IS_EINTR(status)) { return status; } /* Our old behaviour here was to continue after accept() * errors. But this leads us into lots of troubles * because most of the errors are quite fatal. For * example, EMFILE can be caused by slow descriptor * leaks (say in a 3rd party module, or libc). It's * foolish for us to continue after an EMFILE. We also * seem to tickle kernel bugs on some platforms which * lead to never-ending loops here. So it seems best * to just exit in most cases. */ switch (status) { #if defined(HPUX11) && defined(ENOBUFS) /* On HPUX 11.x, the 'ENOBUFS, No buffer space available' * error occurs because the accept() cannot complete. * You will not see ENOBUFS with 10.20 because the kernel * hides any occurrence from being returned to user space. * ENOBUFS with 11.x's TCP/IP stack is possible, and could * occur intermittently. As a work-around, we are going to * ignore ENOBUFS. */ case ENOBUFS: #endif #ifdef EPROTO /* EPROTO on certain older kernels really means * ECONNABORTED, so we need to ignore it for them. * See discussion in new-httpd archives nh.9701 * search for EPROTO. * * Also see nh.9603, search for EPROTO: * There is potentially a bug in Solaris 2.x x<6, * and other boxes that implement tcp sockets in * userland (i.e. on top of STREAMS). On these * systems, EPROTO can actually result in a fatal * loop. See PR#981 for example. It's hard to * handle both uses of EPROTO. */ case EPROTO: #endif #ifdef ECONNABORTED case ECONNABORTED: #endif /* Linux generates the rest of these, other tcp * stacks (i.e. bsd) tend to hide them behind * getsockopt() interfaces. They occur when * the net goes sour or the client disconnects * after the three-way handshake has been done * in the kernel but before userland has picked * up the socket. */ #ifdef ECONNRESET case ECONNRESET: #endif #ifdef ETIMEDOUT case ETIMEDOUT: #endif #ifdef EHOSTUNREACH case EHOSTUNREACH: #endif #ifdef ENETUNREACH case ENETUNREACH: #endif /* EAGAIN/EWOULDBLOCK can be returned on BSD-derived * TCP stacks when the connection is aborted before * we call connect, but only because our listener * sockets are non-blocking (AP_NONBLOCK_WHEN_MULTI_LISTEN) */ #ifdef EAGAIN case EAGAIN: #endif #ifdef EWOULDBLOCK #if !defined(EAGAIN) || EAGAIN != EWOULDBLOCK case EWOULDBLOCK: #endif #endif break; #ifdef ENETDOWN case ENETDOWN: /* * When the network layer has been shut down, there * is not much use in simply exiting: the parent * would simply re-create us (and we'd fail again). * Use the CHILDFATAL code to tear the server down. * @@@ Martin's idea for possible improvement: * A different approach would be to define * a new APEXIT_NETDOWN exit code, the reception * of which would make the parent shutdown all * children, then idle-loop until it detected that * the network is up again, and restart the children. * Ben Hyde noted that temporary ENETDOWN situations * occur in mobile IP. */ ap_log_error(APLOG_MARK, APLOG_EMERG, status, ap_server_conf, "apr_socket_accept: giving up."); return APR_EGENERAL; #endif /*ENETDOWN*/ default: /* If the socket has been closed in ap_close_listeners() * by the restart/stop action, we may get EBADF. * Do not print an error in this case. */ if (!lr->active) { ap_log_error(APLOG_MARK, APLOG_DEBUG, status, ap_server_conf, "apr_socket_accept failed for inactive listener"); return status; } ap_log_error(APLOG_MARK, APLOG_ERR, status, ap_server_conf, "apr_socket_accept: (client socket)"); return APR_EGENERAL; } return status; } #ifdef _OSD_POSIX #include "apr_lib.h" #define USER_LEN 8 typedef enum { bs2_unknown, /* not initialized yet. */ bs2_noFORK, /* no fork() because -X flag was specified */ bs2_FORK, /* only fork() because uid != 0 */ bs2_UFORK /* Normally, ufork() is used to switch identities. */ } bs2_ForkType; static bs2_ForkType forktype = bs2_unknown; static void ap_str_toupper(char *str) { while (*str) { *str = apr_toupper(*str); ++str; } } /* Determine the method for forking off a child in such a way as to * set both the POSIX and BS2000 user id's to the unprivileged user. */ static bs2_ForkType os_forktype(int one_process) { /* have we checked the OS version before? If yes return the previous * result - the OS release isn't going to change suddenly! */ if (forktype == bs2_unknown) { /* not initialized yet */ /* No fork if the one_process option was set */ if (one_process) { forktype = bs2_noFORK; } /* If the user is unprivileged, use the normal fork() only. */ else if (getuid() != 0) { forktype = bs2_FORK; } else forktype = bs2_UFORK; } return forktype; } /* This routine complements the setuid() call: it causes the BS2000 job * environment to be switched to the target user's user id. * That is important if CGI scripts try to execute native BS2000 commands. */ int os_init_job_environment(server_rec *server, const char *user_name, int one_process) { bs2_ForkType type = os_forktype(one_process); /* We can be sure that no change to uid==0 is possible because of * the checks in http_core.c:set_user() */ if (one_process) { type = forktype = bs2_noFORK; ap_log_error(APLOG_MARK, APLOG_ERR, 0, server, "The debug mode of Apache should only " "be started by an unprivileged user!"); return 0; } return 0; } /* BS2000 requires a "special" version of fork() before a setuid() call */ pid_t os_fork(const char *user) { pid_t pid; char username[USER_LEN+1]; switch (os_forktype(0)) { case bs2_FORK: pid = fork(); break; case bs2_UFORK: apr_cpystrn(username, user, sizeof username); /* Make user name all upper case - for some versions of ufork() */ ap_str_toupper(username); pid = ufork(username); if (pid == -1 && errno == EPERM) { ap_log_error(APLOG_MARK, APLOG_EMERG, errno, ap_server_conf, "ufork: Possible mis-configuration " "for user %s - Aborting.", user); exit(1); } break; default: pid = 0; break; } return pid; } #endif /* _OSD_POSIX */