/* 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 "apr_arch_threadproc.h"

#include "apr_strings.h"

#include "apr_portable.h"

#include "apr_signal.h"

#include "apr_random.h"

#include "apr_crypto.h"

/* Heavy on no'ops, here's what we want to pass if there is APR_NO_FILE

 * requested for a specific child handle;

 */

static apr_file_t no_file = { NULL, -1, };

APR_DECLARE(apr_status_t) apr_procattr_create(apr_procattr_t **new,

                                              apr_pool_t *pool)

{

    (*new) = (apr_procattr_t *)apr_pcalloc(pool, sizeof(apr_procattr_t));

    if ((*new) == NULL) {

        return APR_ENOMEM;

    }

    (*new)->pool = pool;

    (*new)->cmdtype = APR_PROGRAM;

    (*new)->uid = (*new)->gid = -1;

    return APR_SUCCESS;

}

APR_DECLARE(apr_status_t) apr_procattr_io_set(apr_procattr_t *attr,

                                              apr_int32_t in,

                                              apr_int32_t out,

                                              apr_int32_t err)

{

    apr_status_t rv;

    if ((in != APR_NO_PIPE) && (in != APR_NO_FILE)) {

        /* APR_CHILD_BLOCK maps to APR_WRITE_BLOCK, while

         * APR_PARENT_BLOCK maps to APR_READ_BLOCK, so transpose

         * the CHILD/PARENT blocking flags for the stdin pipe.

         * stdout/stderr map to the correct mode by default.

         */

        if (in == APR_CHILD_BLOCK)

            in = APR_READ_BLOCK;

        else if (in == APR_PARENT_BLOCK)

            in = APR_WRITE_BLOCK;

        if ((rv = apr_file_pipe_create_ex(&attr->child_in, &attr->parent_in,

                                          in, attr->pool)) == APR_SUCCESS)

            rv = apr_file_inherit_unset(attr->parent_in);

        if (rv != APR_SUCCESS)

            return rv;

    }

    else if (in == APR_NO_FILE)

        attr->child_in = &no_file;

    if ((out != APR_NO_PIPE) && (out != APR_NO_FILE)) {

        if ((rv = apr_file_pipe_create_ex(&attr->parent_out, &attr->child_out,

                                          out, attr->pool)) == APR_SUCCESS)

            rv = apr_file_inherit_unset(attr->parent_out);

        if (rv != APR_SUCCESS)

            return rv;

    }

    else if (out == APR_NO_FILE)

        attr->child_out = &no_file;

    if ((err != APR_NO_PIPE) && (err != APR_NO_FILE)) {

        if ((rv = apr_file_pipe_create_ex(&attr->parent_err, &attr->child_err,

                                          err, attr->pool)) == APR_SUCCESS)

            rv = apr_file_inherit_unset(attr->parent_err);

        if (rv != APR_SUCCESS)

            return rv;

    }

    else if (err == APR_NO_FILE)

        attr->child_err = &no_file;

    return APR_SUCCESS;

}

APR_DECLARE(apr_status_t) apr_procattr_child_in_set(apr_procattr_t *attr,

                                                    apr_file_t *child_in,

                                                    apr_file_t *parent_in)

{

    apr_status_t rv = APR_SUCCESS;

    if (attr->child_in == NULL && attr->parent_in == NULL

           && child_in == NULL && parent_in == NULL)

        if ((rv = apr_file_pipe_create(&attr->child_in, &attr->parent_in,

                                       attr->pool)) == APR_SUCCESS)

            rv = apr_file_inherit_unset(attr->parent_in);

    if (child_in != NULL && rv == APR_SUCCESS) {

        if (attr->child_in && (attr->child_in->filedes != -1))

            rv = apr_file_dup2(attr->child_in, child_in, attr->pool);

        else {

            attr->child_in = NULL;

            if ((rv = apr_file_dup(&attr->child_in, child_in, attr->pool))

                    == APR_SUCCESS)

                rv = apr_file_inherit_set(attr->child_in);

        }

    }

    if (parent_in != NULL && rv == APR_SUCCESS) {

        if (attr->parent_in)

            rv = apr_file_dup2(attr->parent_in, parent_in, attr->pool);

        else

            rv = apr_file_dup(&attr->parent_in, parent_in, attr->pool);

    }

    return rv;

}

APR_DECLARE(apr_status_t) apr_procattr_child_out_set(apr_procattr_t *attr,

                                                     apr_file_t *child_out,

                                                     apr_file_t *parent_out)

{

    apr_status_t rv = APR_SUCCESS;

    if (attr->child_out == NULL && attr->parent_out == NULL

           && child_out == NULL && parent_out == NULL)

        if ((rv = apr_file_pipe_create(&attr->parent_out, &attr->child_out,

                                       attr->pool)) == APR_SUCCESS)

            rv = apr_file_inherit_unset(attr->parent_out);

    if (child_out != NULL && rv == APR_SUCCESS) {

        if (attr->child_out && (attr->child_out->filedes != -1))

            rv = apr_file_dup2(attr->child_out, child_out, attr->pool);

        else {

            attr->child_out = NULL;

            if ((rv = apr_file_dup(&attr->child_out, child_out, attr->pool))

                    == APR_SUCCESS)

                rv = apr_file_inherit_set(attr->child_out);

        }

    }

    if (parent_out != NULL && rv == APR_SUCCESS) {

        if (attr->parent_out)

            rv = apr_file_dup2(attr->parent_out, parent_out, attr->pool);

        else

            rv = apr_file_dup(&attr->parent_out, parent_out, attr->pool);

    }

    return rv;

}

APR_DECLARE(apr_status_t) apr_procattr_child_err_set(apr_procattr_t *attr,

                                                     apr_file_t *child_err,

                                                     apr_file_t *parent_err)

{

    apr_status_t rv = APR_SUCCESS;

    if (attr->child_err == NULL && attr->parent_err == NULL

           && child_err == NULL && parent_err == NULL)

        if ((rv = apr_file_pipe_create(&attr->parent_err, &attr->child_err,

                                      attr->pool)) == APR_SUCCESS)

            rv = apr_file_inherit_unset(attr->parent_err);

    if (child_err != NULL && rv == APR_SUCCESS) {

        if (attr->child_err && (attr->child_err->filedes != -1))

            rv = apr_file_dup2(attr->child_err, child_err, attr->pool);

        else {

            attr->child_err = NULL;

            if ((rv = apr_file_dup(&attr->child_err, child_err, attr->pool))

                    == APR_SUCCESS)

                rv = apr_file_inherit_set(attr->child_err);

        }

    }

    if (parent_err != NULL && rv == APR_SUCCESS) {

        if (attr->parent_err)

            rv = apr_file_dup2(attr->parent_err, parent_err, attr->pool);

        else

            rv = apr_file_dup(&attr->parent_err, parent_err, attr->pool);

    }

    return rv;

}

APR_DECLARE(apr_status_t) apr_procattr_dir_set(apr_procattr_t *attr,

                                               const char *dir)

{

    attr->currdir = apr_pstrdup(attr->pool, dir);

    if (attr->currdir) {

        return APR_SUCCESS;

    }

    return APR_ENOMEM;

}

APR_DECLARE(apr_status_t) apr_procattr_cmdtype_set(apr_procattr_t *attr,

                                                   apr_cmdtype_e cmd)

{

    attr->cmdtype = cmd;

    return APR_SUCCESS;

}

APR_DECLARE(apr_status_t) apr_procattr_detach_set(apr_procattr_t *attr,

                                                  apr_int32_t detach)

{

    attr->detached = detach;

    return APR_SUCCESS;

}

APR_DECLARE(apr_status_t) apr_proc_fork(apr_proc_t *proc, apr_pool_t *pool)

{

    int pid;

    memset(proc, 0, sizeof(apr_proc_t));

    /* Rekey PRNG(s) to clear buffer(s) and make sure that the

     * state(s) change between fork()s in any case.

     */

#if APU_HAVE_CRYPTO_PRNG

    apr_crypto_prng_rekey(NULL);

#endif

    if ((pid = fork()) < 0) {

        return errno;

    }

    else if (pid == 0) {

#if APR_HAS_THREAD_LOCAL

        apr_thread_current_after_fork();

#endif

        proc->pid = getpid();

        /* Do the work needed for children PRNG(s). */

#if APU_HAVE_CRYPTO_PRNG

        apr_crypto_prng_after_fork(NULL, APR_CRYPTO_FORK_INCHILD);

#endif

        apr_random_after_fork(proc);

        return APR_INCHILD;

    }

    proc->pid = pid;

    /* Do the work needed for parent PRNG(s). */

#if APU_HAVE_CRYPTO_PRNG

    apr_crypto_prng_after_fork(NULL, APR_CRYPTO_FORK_INPARENT);

#endif

    return APR_INPARENT;

}

static apr_status_t limit_proc(apr_procattr_t *attr)

{

#if APR_HAVE_STRUCT_RLIMIT && APR_HAVE_SETRLIMIT

#ifdef RLIMIT_CPU

    if (attr->limit_cpu != NULL) {

        if ((setrlimit(RLIMIT_CPU, attr->limit_cpu)) != 0) {

            return errno;

        }

    }

#endif

#ifdef RLIMIT_NPROC

    if (attr->limit_nproc != NULL) {

        if ((setrlimit(RLIMIT_NPROC, attr->limit_nproc)) != 0) {

            return errno;

        }

    }

#endif

#ifdef RLIMIT_NOFILE

    if (attr->limit_nofile != NULL) {

        if ((setrlimit(RLIMIT_NOFILE, attr->limit_nofile)) != 0) {

            return errno;

        }

    }

#endif

#if defined(RLIMIT_AS)

    if (attr->limit_mem != NULL) {

        if ((setrlimit(RLIMIT_AS, attr->limit_mem)) != 0) {

            return errno;

        }

    }

#elif defined(RLIMIT_DATA)

    if (attr->limit_mem != NULL) {

        if ((setrlimit(RLIMIT_DATA, attr->limit_mem)) != 0) {

            return errno;

        }

    }

#elif defined(RLIMIT_VMEM)

    if (attr->limit_mem != NULL) {

        if ((setrlimit(RLIMIT_VMEM, attr->limit_mem)) != 0) {

            return errno;

        }

    }

#endif

#else

    /*

     * Maybe make a note in error_log that setrlimit isn't supported??

     */

#endif

    return APR_SUCCESS;

}

APR_DECLARE(apr_status_t) apr_procattr_child_errfn_set(apr_procattr_t *attr,

                                                       apr_child_errfn_t *errfn)

{

    attr->errfn = errfn;

    return APR_SUCCESS;

}

APR_DECLARE(apr_status_t) apr_procattr_error_check_set(apr_procattr_t *attr,

                                                       apr_int32_t chk)

{

    attr->errchk = chk;

    return APR_SUCCESS;

}

APR_DECLARE(apr_status_t) apr_procattr_addrspace_set(apr_procattr_t *attr,

                                                       apr_int32_t addrspace)

{

    /* won't ever be used on this platform, so don't save the flag */

    return APR_SUCCESS;

}

APR_DECLARE(apr_status_t) apr_procattr_user_set(apr_procattr_t *attr,

                                                const char *username,

                                                const char *password)

{

    apr_status_t rv;

    apr_gid_t    gid;

    if ((rv = apr_uid_get(&attr->uid, &gid, username,

                          attr->pool)) != APR_SUCCESS) {

        attr->uid = -1;

        return rv;

    }

    /* Use default user group if not already set */

    if (attr->gid == -1) {

        attr->gid = gid;

    }

    return APR_SUCCESS;

}

APR_DECLARE(apr_status_t) apr_procattr_group_set(apr_procattr_t *attr,

                                                 const char *groupname)

{

    apr_status_t rv;

    if ((rv = apr_gid_get(&attr->gid, groupname, attr->pool)) != APR_SUCCESS)

        attr->gid = -1;

    return rv;

}

APR_DECLARE(apr_status_t) apr_proc_create(apr_proc_t *new,

                                          const char *progname,

                                          const char * const *args,

                                          const char * const *env,

                                          apr_procattr_t *attr,

                                          apr_pool_t *pool)

{

    int i;

    const char * const empty_envp[] = {NULL};

    if (!env) { /* Specs require an empty array instead of NULL;

                 * Purify will trigger a failure, even if many

                 * implementations don't.

                 */

        env = empty_envp;

    }

    new->in = attr->parent_in;

    new->err = attr->parent_err;

    new->out = attr->parent_out;

    if (attr->errchk) {

        if (attr->currdir) {

            if (access(attr->currdir, X_OK) == -1) {

                /* chdir() in child wouldn't have worked */

                return errno;

            }

        }

        if (attr->cmdtype == APR_PROGRAM ||

            attr->cmdtype == APR_PROGRAM_ENV ||

            *progname == '/') {

            /* for both of these values of cmdtype, caller must pass

             * full path, so it is easy to check;

             * caller can choose to pass full path for other

             * values of cmdtype

             */

            if (access(progname, X_OK) == -1) {

                /* exec*() in child wouldn't have worked */

                return errno;

            }

        }

        else {

            /* todo: search PATH for progname then try to access it */

        }

    }

    if ((new->pid = fork()) < 0) {

        return errno;

    }

    else if (new->pid == 0) {

        /* child process */

        /*

         * If we do exec cleanup before the dup2() calls to set up pipes

         * on 0-2, we accidentally close the pipes used by programs like

         * mod_cgid.

         *

         * If we do exec cleanup after the dup2() calls, cleanup can accidentally

         * close our pipes which replaced any files which previously had

         * descriptors 0-2.

         *

         * The solution is to kill the cleanup for the pipes, then do

         * exec cleanup, then do the dup2() calls.

         */

        if (attr->child_in) {

            apr_pool_cleanup_kill(apr_file_pool_get(attr->child_in),

                                  attr->child_in, apr_unix_file_cleanup);

        }

        if (attr->child_out) {

            apr_pool_cleanup_kill(apr_file_pool_get(attr->child_out),

                                  attr->child_out, apr_unix_file_cleanup);

        }

        if (attr->child_err) {

            apr_pool_cleanup_kill(apr_file_pool_get(attr->child_err),

                                  attr->child_err, apr_unix_file_cleanup);

        }

        apr_pool_cleanup_for_exec();

        if ((attr->child_in) && (attr->child_in->filedes == -1)) {

            close(STDIN_FILENO);

        }

        else if (attr->child_in &&

                 attr->child_in->filedes != STDIN_FILENO) {

            dup2(attr->child_in->filedes, STDIN_FILENO);

            apr_file_close(attr->child_in);

        }

        if ((attr->child_out) && (attr->child_out->filedes == -1)) {

            close(STDOUT_FILENO);

        }

        else if (attr->child_out &&

                 attr->child_out->filedes != STDOUT_FILENO) {

            dup2(attr->child_out->filedes, STDOUT_FILENO);

            apr_file_close(attr->child_out);

        }

        if ((attr->child_err) && (attr->child_err->filedes == -1)) {

            close(STDERR_FILENO);

        }

        else if (attr->child_err &&

                 attr->child_err->filedes != STDERR_FILENO) {

            dup2(attr->child_err->filedes, STDERR_FILENO);

            apr_file_close(attr->child_err);

        }

        apr_signal(SIGCHLD, SIG_DFL); /* not sure if this is needed or not */

        if (attr->currdir != NULL) {

            if (chdir(attr->currdir) == -1) {

                if (attr->errfn) {

                    attr->errfn(pool, errno, "change of working directory failed");

                }

                _exit(-1);   /* We have big problems, the child should exit. */

            }

        }

        if (!geteuid()) {

            apr_procattr_pscb_t *c = attr->perms_set_callbacks;

            while (c) {

                apr_status_t r;

                r = (*c->perms_set_fn)((void *)c->data, c->perms,

                                       attr->uid, attr->gid);

                if (r != APR_SUCCESS && r != APR_ENOTIMPL) {

                    _exit(-1);

                }

                c = c->next;

            }

        }

        /* Only try to switch if we are running as root */

        if (attr->gid != -1 && !geteuid()) {

            if (setgid(attr->gid)) {

                if (attr->errfn) {

                    attr->errfn(pool, errno, "setting of group failed");

                }

                _exit(-1);   /* We have big problems, the child should exit. */

            }

        }

        if (attr->uid != -1 && !geteuid()) {

            if (setuid(attr->uid)) {

                if (attr->errfn) {

                    attr->errfn(pool, errno, "setting of user failed");

                }

                _exit(-1);   /* We have big problems, the child should exit. */

            }

        }

        if (limit_proc(attr) != APR_SUCCESS) {

            if (attr->errfn) {

                attr->errfn(pool, errno, "setting of resource limits failed");

            }

            _exit(-1);   /* We have big problems, the child should exit. */

        }

        if (attr->cmdtype == APR_SHELLCMD ||

            attr->cmdtype == APR_SHELLCMD_ENV) {

            int onearg_len = 0;

            const char *newargs[4];

            newargs[0] = SHELL_PATH;

            newargs[1] = "-c";

            i = 0;

            while (args[i]) {

                onearg_len += strlen(args[i]);

                onearg_len++; /* for space delimiter */

                i++;

            }

            switch(i) {

            case 0:

                /* bad parameters; we're doomed */

                break;

            case 1:

                /* no args, or caller already built a single string from

                 * progname and args

                 */

                newargs[2] = args[0];

                break;

            default:

            {

                char *ch, *onearg;

                ch = onearg = apr_palloc(pool, onearg_len);

                i = 0;

                while (args[i]) {

                    size_t len = strlen(args[i]);

                    memcpy(ch, args[i], len);

                    ch += len;

                    *ch = ' ';

                    ++ch;

                    ++i;

                }

                --ch; /* back up to trailing blank */

                *ch = '\0';

                newargs[2] = onearg;

            }

            }

            newargs[3] = NULL;

            if (attr->detached) {

                apr_proc_detach(APR_PROC_DETACH_DAEMONIZE);

            }

            if (attr->cmdtype == APR_SHELLCMD) {

                execve(SHELL_PATH, (char * const *) newargs, (char * const *)env);

            }

            else {

                execv(SHELL_PATH, (char * const *)newargs);

            }

        }

        else if (attr->cmdtype == APR_PROGRAM) {

            if (attr->detached) {

                apr_proc_detach(APR_PROC_DETACH_DAEMONIZE);

            }

            execve(progname, (char * const *)args, (char * const *)env);

        }

        else if (attr->cmdtype == APR_PROGRAM_ENV) {

            if (attr->detached) {

                apr_proc_detach(APR_PROC_DETACH_DAEMONIZE);

            }

            execv(progname, (char * const *)args);

        }

        else {

            /* APR_PROGRAM_PATH */

            if (attr->detached) {

                apr_proc_detach(APR_PROC_DETACH_DAEMONIZE);

            }

            execvp(progname, (char * const *)args);

        }

        if (attr->errfn) {

            char *desc;

            desc = apr_psprintf(pool, "exec of '%s' failed",

                                progname);

            attr->errfn(pool, errno, desc);

        }

        _exit(-1);  /* if we get here, there is a problem, so exit with an

                     * error code. */

    }

    /* Parent process */

    if (attr->child_in && (attr->child_in->filedes != -1)) {

        apr_file_close(attr->child_in);

    }

    if (attr->child_out && (attr->child_out->filedes != -1)) {

        apr_file_close(attr->child_out);

    }

    if (attr->child_err && (attr->child_err->filedes != -1)) {

        apr_file_close(attr->child_err);

    }

    return APR_SUCCESS;

}

APR_DECLARE(apr_status_t) apr_proc_wait_all_procs(apr_proc_t *proc,

                                                  int *exitcode,

                                                  apr_exit_why_e *exitwhy,

                                                  apr_wait_how_e waithow,

                                                  apr_pool_t *p)

{

    proc->pid = -1;

    return apr_proc_wait(proc, exitcode, exitwhy, waithow);

}

APR_DECLARE(apr_status_t) apr_proc_wait(apr_proc_t *proc,

                                        int *exitcode, apr_exit_why_e *exitwhy,

                                        apr_wait_how_e waithow)

{

    pid_t pstatus;

    int waitpid_options = WUNTRACED;

    int exit_int;

    int ignore;

    apr_exit_why_e ignorewhy;

    if (exitcode == NULL) {

        exitcode = &ignore;

    }

    if (exitwhy == NULL) {

        exitwhy = &ignorewhy;

    }

    if (waithow != APR_WAIT) {

        waitpid_options |= WNOHANG;

    }

    do {

        pstatus = waitpid(proc->pid, &exit_int, waitpid_options);

    } while (pstatus < 0 && errno == EINTR);

    if (pstatus > 0) {

        proc->pid = pstatus;

        if (WIFEXITED(exit_int)) {

            *exitwhy = APR_PROC_EXIT;

            *exitcode = WEXITSTATUS(exit_int);

        }

        else if (WIFSIGNALED(exit_int)) {

            *exitwhy = APR_PROC_SIGNAL;

#ifdef WCOREDUMP

            if (WCOREDUMP(exit_int)) {

                *exitwhy |= APR_PROC_SIGNAL_CORE;

            }

#endif

            *exitcode = WTERMSIG(exit_int);

        }

        else {

            /* unexpected condition */

            return APR_EGENERAL;

        }

        return APR_CHILD_DONE;

    }

    else if (pstatus == 0) {

        return APR_CHILD_NOTDONE;

    }

    return errno;

}

#if APR_HAVE_STRUCT_RLIMIT

APR_DECLARE(apr_status_t) apr_procattr_limit_set(apr_procattr_t *attr,

                                                 apr_int32_t what,

                                                 struct rlimit *limit)

{

    switch(what) {

        case APR_LIMIT_CPU:

#ifdef RLIMIT_CPU

            attr->limit_cpu = limit;

            break;

#else

            return APR_ENOTIMPL;

#endif

        case APR_LIMIT_MEM:

#if defined(RLIMIT_DATA) || defined(RLIMIT_VMEM) || defined(RLIMIT_AS)

            attr->limit_mem = limit;

            break;

#else

            return APR_ENOTIMPL;

#endif

        case APR_LIMIT_NPROC:

#ifdef RLIMIT_NPROC

            attr->limit_nproc = limit;

            break;

#else

            return APR_ENOTIMPL;

#endif

        case APR_LIMIT_NOFILE:

#ifdef RLIMIT_NOFILE

            attr->limit_nofile = limit;

            break;

#else

            return APR_ENOTIMPL;

#endif

    }

    return APR_SUCCESS;

}

#endif /* APR_HAVE_STRUCT_RLIMIT */

APR_DECLARE(apr_status_t) apr_procattr_perms_set_register(apr_procattr_t *attr,

                                                 apr_perms_setfn_t *perms_set_fn,

                                                 void *data,

                                                 apr_fileperms_t perms)

{

    apr_procattr_pscb_t *c;

    c = apr_palloc(attr->pool, sizeof(apr_procattr_pscb_t));

    c->data = data;

    c->perms = perms;

    c->perms_set_fn = perms_set_fn;

    c->next = attr->perms_set_callbacks;

    attr->perms_set_callbacks = c;

    return APR_SUCCESS;

}