/*      $OpenBSD: proc.c,v 1.53 2026/03/02 19:24:58 rsadowski Exp $     */

/*
 * Copyright (c) 2010 - 2016 Reyk Floeter <reyk@openbsd.org>
 * Copyright (c) 2008 Pierre-Yves Ritschard <pyr@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/wait.h>

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <signal.h>
#include <paths.h>
#include <pwd.h>
#include <event.h>
#include <imsg.h>

#include "httpd.h"
#include "log.h"

void     proc_exec(struct privsep *, struct privsep_proc *, unsigned int, int,
            char **);
void     proc_setup(struct privsep *, struct privsep_proc *, unsigned int);
void     proc_open(struct privsep *, int, int);
void     proc_accept(struct privsep *, int, enum privsep_procid,
            unsigned int);
void     proc_close(struct privsep *);
void     proc_shutdown(struct privsep_proc *);
void     proc_sig_handler(int, short, void *);
void     proc_range(struct privsep *, enum privsep_procid, int *, int *);
int      proc_dispatch_null(int, struct privsep_proc *, struct imsg *);

enum privsep_procid
proc_getid(struct privsep_proc *procs, unsigned int nproc,
    const char *proc_name)
{
        struct privsep_proc     *p;
        unsigned int             proc;

        for (proc = 0; proc < nproc; proc++) {
                p = &procs[proc];
                if (strcmp(p->p_title, proc_name))
                        continue;

                return (p->p_id);
        }

        return (PROC_MAX);
}

void
proc_exec(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc,
    int argc, char **argv)
{
        unsigned int             proc, nargc, i, proc_i;
        char                    **nargv;
        struct privsep_proc     *p;
        char                     num[32];
        int                      fd;

        /* Prepare the new process argv. */
        nargv = calloc(argc + 5, sizeof(char *));
        if (nargv == NULL)
                fatal("%s: calloc", __func__);

        /* Copy call argument first. */
        nargc = 0;
        nargv[nargc++] = argv[0];

        /* Set process name argument and save the position. */
        nargv[nargc++] = "-P";
        proc_i = nargc;
        nargc++;

        /* Point process instance arg to stack and copy the original args. */
        nargv[nargc++] = "-I";
        nargv[nargc++] = num;
        for (i = 1; i < (unsigned int) argc; i++)
                nargv[nargc++] = argv[i];

        nargv[nargc] = NULL;

        for (proc = 0; proc < nproc; proc++) {
                p = &procs[proc];

                /* Update args with process title. */
                nargv[proc_i] = (char *)(uintptr_t)p->p_title;

                /* Fire children processes. */
                for (i = 0; i < ps->ps_instances[p->p_id]; i++) {
                        /* Update the process instance number. */
                        snprintf(num, sizeof(num), "%u", i);

                        fd = ps->ps_pipes[p->p_id][i].pp_pipes[PROC_PARENT][0];
                        ps->ps_pipes[p->p_id][i].pp_pipes[PROC_PARENT][0] = -1;

                        switch (fork()) {
                        case -1:
                                fatal("%s: fork", __func__);
                                break;
                        case 0:
                                /* Prepare parent socket. */
                                if (fd != PROC_PARENT_SOCK_FILENO) {
                                        if (dup2(fd, PROC_PARENT_SOCK_FILENO)
                                            == -1)
                                                fatal("dup2");
                                } else if (fcntl(fd, F_SETFD, 0) == -1)
                                        fatal("fcntl");

                                execvp(argv[0], nargv);
                                fatal("%s: execvp", __func__);
                                break;
                        default:
                                /* Close child end. */
                                close(fd);
                                break;
                        }
                }
        }
        free(nargv);
}

void
proc_connect(struct privsep *ps)
{
        struct imsgev           *iev;
        unsigned int             src, dst, inst;

        /* Don't distribute any sockets if we are not really going to run. */
        if (ps->ps_noaction)
                return;

        for (dst = 0; dst < PROC_MAX; dst++) {
                /* We don't communicate with ourselves. */
                if (dst == PROC_PARENT)
                        continue;

                for (inst = 0; inst < ps->ps_instances[dst]; inst++) {
                        iev = &ps->ps_ievs[dst][inst];
                        if (imsgbuf_init(&iev->ibuf,
                            ps->ps_pp->pp_pipes[dst][inst]) == -1)
                                fatal(NULL);
                        imsgbuf_allow_fdpass(&iev->ibuf);
                        event_set(&iev->ev, iev->ibuf.fd, iev->events,
                            iev->handler, iev->data);
                        event_add(&iev->ev, NULL);
                }
        }

        /* Distribute the socketpair()s for everyone. */
        for (src = 0; src < PROC_MAX; src++)
                for (dst = src; dst < PROC_MAX; dst++) {
                        /* Parent already distributed its fds. */
                        if (src == PROC_PARENT || dst == PROC_PARENT)
                                continue;

                        proc_open(ps, src, dst);
                }
}

void
proc_init(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc,
    int debug, int argc, char **argv, enum privsep_procid proc_id)
{
        struct privsep_proc     *p = NULL;
        struct privsep_pipes    *pa, *pb;
        unsigned int             proc;
        unsigned int             dst;
        int                      fds[2];

        /* Don't initiate anything if we are not really going to run. */
        if (ps->ps_noaction)
                return;

        if (proc_id == PROC_PARENT) {
                privsep_process = PROC_PARENT;
                proc_setup(ps, procs, nproc);

                if (!debug && daemon(1, 0) == -1)
                        fatal("failed to daemonize");

                /*
                 * Create the children sockets so we can use them
                 * to distribute the rest of the socketpair()s using
                 * proc_connect() later.
                 */
                for (dst = 0; dst < PROC_MAX; dst++) {
                        /* Don't create socket for ourselves. */
                        if (dst == PROC_PARENT)
                                continue;

                        for (proc = 0; proc < ps->ps_instances[dst]; proc++) {
                                pa = &ps->ps_pipes[PROC_PARENT][0];
                                pb = &ps->ps_pipes[dst][proc];
                                if (socketpair(AF_UNIX,
                                    SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC,
                                    PF_UNSPEC, fds) == -1)
                                        fatal("%s: socketpair", __func__);

                                pa->pp_pipes[dst][proc] = fds[0];
                                pb->pp_pipes[PROC_PARENT][0] = fds[1];
                        }
                }

                /* Engage! */
                proc_exec(ps, procs, nproc, argc, argv);
                return;
        }

        /* Initialize a child */
        for (proc = 0; proc < nproc; proc++) {
                if (procs[proc].p_id != proc_id)
                        continue;
                p = &procs[proc];
                break;
        }
        if (p == NULL || p->p_init == NULL)
                fatalx("%s: process %d missing process initialization",
                    __func__, proc_id);

        p->p_init(ps, p);

        fatalx("failed to initiate child process");
}

void
proc_accept(struct privsep *ps, int fd, enum privsep_procid dst,
    unsigned int n)
{
        struct privsep_pipes    *pp = ps->ps_pp;
        struct imsgev           *iev;

        if (ps->ps_ievs[dst] == NULL) {
#if DEBUG > 1
                log_debug("%s: %s src %d %d to dst %d %d not connected",
                    __func__, ps->ps_title[privsep_process],
                    privsep_process, ps->ps_instance + 1,
                    dst, n + 1);
#endif
                close(fd);
                return;
        }

        if (pp->pp_pipes[dst][n] != -1) {
                log_warnx("%s: duplicated descriptor", __func__);
                close(fd);
                return;
        } else
                pp->pp_pipes[dst][n] = fd;

        iev = &ps->ps_ievs[dst][n];
        if (imsgbuf_init(&iev->ibuf, fd) == -1)
                fatal(NULL);
        imsgbuf_allow_fdpass(&iev->ibuf);
        event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev->data);
        event_add(&iev->ev, NULL);
}

void
proc_setup(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc)
{
        unsigned int             i, j, src, dst, id;
        struct privsep_pipes    *pp;

        /* Initialize parent title, ps_instances and procs. */
        ps->ps_title[PROC_PARENT] = "parent";

        for (src = 0; src < PROC_MAX; src++)
                /* Default to 1 process instance */
                if (ps->ps_instances[src] < 1)
                        ps->ps_instances[src] = 1;

        for (src = 0; src < nproc; src++) {
                procs[src].p_ps = ps;
                if (procs[src].p_cb == NULL)
                        procs[src].p_cb = proc_dispatch_null;

                id = procs[src].p_id;
                ps->ps_title[id] = procs[src].p_title;
                if ((ps->ps_ievs[id] = calloc(ps->ps_instances[id],
                    sizeof(struct imsgev))) == NULL)
                        fatal("%s: calloc", __func__);

                /* With this set up, we are ready to call imsgbuf_init(). */
                for (i = 0; i < ps->ps_instances[id]; i++) {
                        ps->ps_ievs[id][i].handler = proc_dispatch;
                        ps->ps_ievs[id][i].events = EV_READ;
                        ps->ps_ievs[id][i].proc = &procs[src];
                        ps->ps_ievs[id][i].data = &ps->ps_ievs[id][i];
                }
        }

        /*
         * Allocate pipes for all process instances (incl. parent)
         *
         * - ps->ps_pipes: N:M mapping
         * N source processes connected to M destination processes:
         * [src][instances][dst][instances], for example
         * [PROC_RELAY][3][PROC_CA][3]
         *
         * - ps->ps_pp: per-process 1:M part of ps->ps_pipes
         * Each process instance has a destination array of socketpair fds:
         * [dst][instances], for example
         * [PROC_PARENT][0]
         */
        for (src = 0; src < PROC_MAX; src++) {
                /* Allocate destination array for each process */
                if ((ps->ps_pipes[src] = calloc(ps->ps_instances[src],
                    sizeof(struct privsep_pipes))) == NULL)
                        fatal("%s: calloc", __func__);

                for (i = 0; i < ps->ps_instances[src]; i++) {
                        pp = &ps->ps_pipes[src][i];

                        for (dst = 0; dst < PROC_MAX; dst++) {
                                /* Allocate maximum fd integers */
                                if ((pp->pp_pipes[dst] =
                                    calloc(ps->ps_instances[dst],
                                    sizeof(int))) == NULL)
                                        fatal("%s: calloc", __func__);

                                /* Mark fd as unused */
                                for (j = 0; j < ps->ps_instances[dst]; j++)
                                        pp->pp_pipes[dst][j] = -1;
                        }
                }
        }

        ps->ps_pp = &ps->ps_pipes[privsep_process][ps->ps_instance];
}

void
proc_kill(struct privsep *ps)
{
        char            *cause;
        pid_t            pid;
        int              len, status;

        if (privsep_process != PROC_PARENT)
                return;

        proc_close(ps);

        do {
                pid = waitpid(WAIT_ANY, &status, 0);
                if (pid <= 0)
                        continue;

                if (WIFSIGNALED(status)) {
                        len = asprintf(&cause, "terminated; signal %d",
                            WTERMSIG(status));
                } else if (WIFEXITED(status)) {
                        if (WEXITSTATUS(status) != 0)
                                len = asprintf(&cause, "exited abnormally");
                        else
                                len = 0;
                } else
                        len = -1;

                if (len == 0) {
                        /* child exited OK, don't print a warning message */
                } else if (len != -1) {
                        log_warnx("lost child: pid %u %s", pid, cause);
                        free(cause);
                } else
                        log_warnx("lost child: pid %u", pid);
        } while (pid != -1 || errno == EINTR);
}

void
proc_open(struct privsep *ps, int src, int dst)
{
        struct privsep_pipes    *pa, *pb;
        struct privsep_fd        pf;
        int                      fds[2];
        unsigned int             i, j;

        /* Exchange pipes between process. */
        for (i = 0; i < ps->ps_instances[src]; i++) {
                for (j = 0; j < ps->ps_instances[dst]; j++) {
                        /* Don't create sockets for ourself. */
                        if (src == dst && i == j)
                                continue;

                        /* Servers don't talk to each other. */
                        if (src == PROC_SERVER && dst == PROC_SERVER)
                                continue;

                        pa = &ps->ps_pipes[src][i];
                        pb = &ps->ps_pipes[dst][j];
                        if (socketpair(AF_UNIX,
                            SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC,
                            PF_UNSPEC, fds) == -1)
                                fatal("%s: socketpair", __func__);

                        pa->pp_pipes[dst][j] = fds[0];
                        pb->pp_pipes[src][i] = fds[1];

                        pf.pf_procid = src;
                        pf.pf_instance = i;
                        if (proc_compose_imsg(ps, dst, j, IMSG_CTL_PROCFD,
                            -1, pb->pp_pipes[src][i], &pf, sizeof(pf)) == -1)
                                fatal("%s: proc_compose_imsg", __func__);

                        pf.pf_procid = dst;
                        pf.pf_instance = j;
                        if (proc_compose_imsg(ps, src, i, IMSG_CTL_PROCFD,
                            -1, pa->pp_pipes[dst][j], &pf, sizeof(pf)) == -1)
                                fatal("%s: proc_compose_imsg", __func__);

                        /*
                         * We have to flush to send the descriptors and close
                         * them to avoid the fd ramp on startup.
                         */
                        if (proc_flush_imsg(ps, src, i) == -1 ||
                            proc_flush_imsg(ps, dst, j) == -1)
                                fatal("%s: imsgbuf_flush", __func__);
                }
        }
}

void
proc_close(struct privsep *ps)
{
        unsigned int             dst, n;
        struct privsep_pipes    *pp;

        if (ps == NULL)
                return;

        pp = ps->ps_pp;

        for (dst = 0; dst < PROC_MAX; dst++) {
                if (ps->ps_ievs[dst] == NULL)
                        continue;

                for (n = 0; n < ps->ps_instances[dst]; n++) {
                        if (pp->pp_pipes[dst][n] == -1)
                                continue;

                        /* Cancel the fd, close and invalidate the fd */
                        event_del(&(ps->ps_ievs[dst][n].ev));
                        imsgbuf_clear(&(ps->ps_ievs[dst][n].ibuf));
                        close(pp->pp_pipes[dst][n]);
                        pp->pp_pipes[dst][n] = -1;
                }
                free(ps->ps_ievs[dst]);
        }
}

void
proc_shutdown(struct privsep_proc *p)
{
        struct privsep  *ps = p->p_ps;

        if (p->p_id == PROC_CONTROL && ps)
                control_cleanup(&ps->ps_csock);

        if (p->p_shutdown != NULL)
                (*p->p_shutdown)();

        proc_close(ps);

        log_info("%s exiting, pid %d", p->p_title, getpid());

        exit(0);
}

void
proc_sig_handler(int sig, short event, void *arg)
{
        struct privsep_proc     *p = arg;

        switch (sig) {
        case SIGINT:
        case SIGTERM:
                proc_shutdown(p);
                break;
        case SIGCHLD:
        case SIGHUP:
        case SIGPIPE:
        case SIGUSR1:
                /* ignore */
                break;
        default:
                fatalx("%s: unexpected signal", __func__);
                /* NOTREACHED */
        }
}

void
proc_run(struct privsep *ps, struct privsep_proc *p,
    struct privsep_proc *procs, unsigned int nproc,
    void (*run)(struct privsep *, struct privsep_proc *, void *), void *arg)
{
        struct passwd           *pw;
        const char              *root;
        struct control_sock     *rcs;

        log_procinit(p->p_title);

        if (p->p_id == PROC_CONTROL && ps->ps_instance == 0) {
                if (control_init(ps, &ps->ps_csock) == -1)
                        fatalx("%s: control_init", __func__);
                TAILQ_FOREACH(rcs, &ps->ps_rcsocks, cs_entry)
                        if (control_init(ps, rcs) == -1)
                                fatalx("%s: control_init", __func__);
        }

        /* Use non-standard user */
        if (p->p_pw != NULL)
                pw = p->p_pw;
        else
                pw = ps->ps_pw;

        /* Change root directory */
        if (p->p_chroot != NULL)
                root = p->p_chroot;
        else
                root = pw->pw_dir;

        if (chroot(root) == -1)
                fatal("%s: chroot", __func__);
        if (chdir("/") == -1)
                fatal("%s: chdir(\"/\")", __func__);

        privsep_process = p->p_id;

        setproctitle("%s", p->p_title);

        if (setgroups(1, &pw->pw_gid) ||
            setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
            setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
                fatal("%s: cannot drop privileges", __func__);

        event_init();

        signal_set(&ps->ps_evsigint, SIGINT, proc_sig_handler, p);
        signal_set(&ps->ps_evsigterm, SIGTERM, proc_sig_handler, p);
        signal_set(&ps->ps_evsigchld, SIGCHLD, proc_sig_handler, p);
        signal_set(&ps->ps_evsighup, SIGHUP, proc_sig_handler, p);
        signal_set(&ps->ps_evsigpipe, SIGPIPE, proc_sig_handler, p);
        signal_set(&ps->ps_evsigusr1, SIGUSR1, proc_sig_handler, p);

        signal_add(&ps->ps_evsigint, NULL);
        signal_add(&ps->ps_evsigterm, NULL);
        signal_add(&ps->ps_evsigchld, NULL);
        signal_add(&ps->ps_evsighup, NULL);
        signal_add(&ps->ps_evsigpipe, NULL);
        signal_add(&ps->ps_evsigusr1, NULL);

        proc_setup(ps, procs, nproc);
        proc_accept(ps, PROC_PARENT_SOCK_FILENO, PROC_PARENT, 0);
        if (p->p_id == PROC_CONTROL && ps->ps_instance == 0) {
                if (control_listen(&ps->ps_csock) == -1)
                        fatalx("%s: control_listen", __func__);
                TAILQ_FOREACH(rcs, &ps->ps_rcsocks, cs_entry)
                        if (control_listen(rcs) == -1)
                                fatalx("%s: control_listen", __func__);
        }

        DPRINTF("%s: %s %d/%d, pid %d", __func__, p->p_title,
            ps->ps_instance + 1, ps->ps_instances[p->p_id], getpid());

        if (run != NULL)
                run(ps, p, arg);

        event_dispatch();

        proc_shutdown(p);
}

void
proc_dispatch(int fd, short event, void *arg)
{
        struct imsgev           *iev = arg;
        struct privsep_proc     *p = iev->proc;
        struct privsep          *ps = p->p_ps;
        struct imsgbuf          *ibuf;
        struct imsg              imsg;
        ssize_t                  n;
        int                      verbose;
        const char              *title;
        struct privsep_fd        pf;

        title = ps->ps_title[privsep_process];
        ibuf = &iev->ibuf;

        if (event & EV_READ) {
                if ((n = imsgbuf_read(ibuf)) == -1)
                        fatal("%s: imsgbuf_read", __func__);
                if (n == 0) {
                        /* this pipe is dead, so remove the event handler */
                        event_del(&iev->ev);
                        event_loopexit(NULL);
                        return;
                }
        }

        if (event & EV_WRITE) {
                if (imsgbuf_write(ibuf) == -1) {
                        if (errno == EPIPE) {   /* connection closed */
                                /* remove the event handler */
                                event_del(&iev->ev);
                                event_loopexit(NULL);
                                return;
                        } else
                                fatal("%s: imsgbuf_write", __func__);
                }
        }

        for (;;) {
                if ((n = imsg_get(ibuf, &imsg)) == -1)
                        fatal("%s: imsg_get", __func__);
                if (n == 0)
                        break;

#if DEBUG > 1
                log_debug("%s: %s %d got imsg %d peerid %d from %s %d",
                    __func__, title, ps->ps_instance + 1,
                    imsg.hdr.type, imsg.hdr.peerid, p->p_title, imsg.hdr.pid);
#endif

                /*
                 * Check the message with the program callback
                 */
                if ((p->p_cb)(fd, p, &imsg) == 0) {
                        /* Message was handled by the callback, continue */
                        imsg_free(&imsg);
                        continue;
                }

                /*
                 * Generic message handling
                 */
                switch (imsg.hdr.type) {
                case IMSG_CTL_VERBOSE:
                        IMSG_SIZE_CHECK(&imsg, &verbose);
                        memcpy(&verbose, imsg.data, sizeof(verbose));
                        log_setverbose(verbose);
                        break;
                case IMSG_CTL_PROCFD:
                        IMSG_SIZE_CHECK(&imsg, &pf);
                        memcpy(&pf, imsg.data, sizeof(pf));
                        proc_accept(ps, imsg_get_fd(&imsg), pf.pf_procid,
                            pf.pf_instance);
                        break;
                default:
                        fatalx("%s: %s %d got invalid imsg %d peerid %d "
                            "from %s %d",
                            __func__, title, ps->ps_instance + 1,
                            imsg.hdr.type, imsg.hdr.peerid,
                            p->p_title, imsg.hdr.pid);
                }
                imsg_free(&imsg);
        }
        imsg_event_add(iev);
}

int
proc_dispatch_null(int fd, struct privsep_proc *p, struct imsg *imsg)
{
        return (-1);
}

/*
 * imsg helper functions
 */

void
imsg_event_add(struct imsgev *iev)
{
        if (iev->handler == NULL) {
                imsgbuf_flush(&iev->ibuf);
                return;
        }

        iev->events = EV_READ;
        if (imsgbuf_queuelen(&iev->ibuf) > 0)
                iev->events |= EV_WRITE;

        event_del(&iev->ev);
        event_set(&iev->ev, iev->ibuf.fd, iev->events, iev->handler, iev->data);
        event_add(&iev->ev, NULL);
}

int
imsg_compose_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
    pid_t pid, int fd, void *data, uint16_t datalen)
{
        int     ret;

        if ((ret = imsg_compose(&iev->ibuf, type, peerid,
            pid, fd, data, datalen)) == -1)
                return (ret);
        imsg_event_add(iev);
        return (ret);
}

int
imsg_composev_event(struct imsgev *iev, uint16_t type, uint32_t peerid,
    pid_t pid, int fd, const struct iovec *iov, int iovcnt)
{
        int     ret;

        if ((ret = imsg_composev(&iev->ibuf, type, peerid,
            pid, fd, iov, iovcnt)) == -1)
                return (ret);
        imsg_event_add(iev);
        return (ret);
}

void
proc_range(struct privsep *ps, enum privsep_procid id, int *n, int *m)
{
        if (*n == -1) {
                /* Use a range of all target instances */
                *n = 0;
                *m = ps->ps_instances[id];
        } else {
                /* Use only a single slot of the specified peer process */
                *m = *n + 1;
        }
}

int
proc_compose_imsg(struct privsep *ps, enum privsep_procid id, int n,
    uint16_t type, uint32_t peerid, int fd, void *data, uint16_t datalen)
{
        int      m;

        proc_range(ps, id, &n, &m);
        for (; n < m; n++) {
                if (imsg_compose_event(&ps->ps_ievs[id][n],
                    type, peerid, ps->ps_instance + 1, fd, data, datalen) == -1)
                        return (-1);
        }

        return (0);
}

int
proc_compose(struct privsep *ps, enum privsep_procid id,
    uint16_t type, void *data, uint16_t datalen)
{
        return (proc_compose_imsg(ps, id, -1, type, -1, -1, data, datalen));
}

int
proc_composev_imsg(struct privsep *ps, enum privsep_procid id, int n,
    uint16_t type, uint32_t peerid, int fd, const struct iovec *iov, int iovcnt)
{
        int      m;

        proc_range(ps, id, &n, &m);
        for (; n < m; n++)
                if (imsg_composev_event(&ps->ps_ievs[id][n],
                    type, peerid, ps->ps_instance + 1, fd, iov, iovcnt) == -1)
                        return (-1);

        return (0);
}

int
proc_composev(struct privsep *ps, enum privsep_procid id,
    uint16_t type, const struct iovec *iov, int iovcnt)
{
        return (proc_composev_imsg(ps, id, -1, type, -1, -1, iov, iovcnt));
}

int
proc_forward_imsg(struct privsep *ps, struct imsg *imsg,
    enum privsep_procid id, int n)
{
        return (proc_compose_imsg(ps, id, n, imsg->hdr.type,
            imsg->hdr.peerid, -1, imsg->data, IMSG_DATA_SIZE(imsg)));
}

struct imsgbuf *
proc_ibuf(struct privsep *ps, enum privsep_procid id, int n)
{
        int      m;

        proc_range(ps, id, &n, &m);
        return (&ps->ps_ievs[id][n].ibuf);
}

struct imsgev *
proc_iev(struct privsep *ps, enum privsep_procid id, int n)
{
        int      m;

        proc_range(ps, id, &n, &m);
        return (&ps->ps_ievs[id][n]);
}

/* This function should only be called with care as it breaks async I/O */
int
proc_flush_imsg(struct privsep *ps, enum privsep_procid id, int n)
{
        struct imsgbuf  *ibuf;
        int              m, ret = 0;

        proc_range(ps, id, &n, &m);
        for (; n < m; n++) {
                if ((ibuf = proc_ibuf(ps, id, n)) == NULL)
                        return (-1);
                if ((ret = imsgbuf_flush(ibuf)) == -1)
                        break;
                imsg_event_add(&ps->ps_ievs[id][n]);
        }

        return (ret);
}