1 files changed, 622 insertions, 0 deletions

diff --git a/httpd/proc.c b/httpd/proc.c
new file mode 100644
index 0000000..34d65c0
--- /dev/null
+++ b/httpd/proc.c
@@ -0,0 +1,622 @@
+/*	$OpenBSD: proc.c,v 1.8 2015/01/21 22:21:05 reyk Exp $	*/
+
+/*
+ * Copyright (c) 2010 - 2014 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 <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <signal.h>
+#include <pwd.h>
+#include <event.h>
+#include <imsg.h>
+
+#include "httpd.h"
+
+void	 proc_open(struct privsep *, struct privsep_proc *,
+	    struct privsep_proc *, size_t);
+void	 proc_close(struct privsep *);
+int	 proc_ispeer(struct privsep_proc *, u_int, enum privsep_procid);
+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_ispeer(struct privsep_proc *procs, u_int nproc, enum privsep_procid type)
+{
+	u_int	i;
+
+	for (i = 0; i < nproc; i++)
+		if (procs[i].p_id == type)
+			return (1);
+	return (0);
+}
+
+void
+proc_init(struct privsep *ps, struct privsep_proc *procs, u_int nproc)
+{
+	u_int			 i, j, src, dst;
+	struct privsep_pipes	*pp;
+
+	/*
+	 * 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_ninstances,
+		    sizeof(struct privsep_pipes))) == NULL)
+			fatal("proc_init: calloc");
+
+		for (i = 0; i < ps->ps_ninstances; 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_ninstances,
+				    sizeof(int))) == NULL)
+					fatal("proc_init: calloc");
+
+				/* Mark fd as unused */
+				for (j = 0; j < ps->ps_ninstances; j++)
+					pp->pp_pipes[dst][j] = -1;
+			}
+		}
+	}
+
+	/*
+	 * Setup and run the parent and its children
+	 */
+	privsep_process = PROC_PARENT;
+	ps->ps_instances[PROC_PARENT] = 1;
+	ps->ps_title[PROC_PARENT] = "parent";
+	ps->ps_pid[PROC_PARENT] = getpid();
+	ps->ps_pp = &ps->ps_pipes[privsep_process][0];
+
+	for (i = 0; i < nproc; i++) {
+		/* Default to 1 process instance */
+		if (ps->ps_instances[procs[i].p_id] < 1)
+			ps->ps_instances[procs[i].p_id] = 1;
+		ps->ps_title[procs[i].p_id] = procs[i].p_title;
+	}
+
+	proc_open(ps, NULL, procs, nproc);
+
+	/* Engage! */
+	for (i = 0; i < nproc; i++)
+		ps->ps_pid[procs[i].p_id] = (*procs[i].p_init)(ps, &procs[i]);
+}
+
+void
+proc_kill(struct privsep *ps)
+{
+	pid_t		 pid;
+	u_int		 i;
+
+	if (privsep_process != PROC_PARENT)
+		return;
+
+	for (i = 0; i < PROC_MAX; i++) {
+		if (ps->ps_pid[i] == 0)
+			continue;
+		killpg(ps->ps_pid[i], SIGTERM);
+	}
+
+	do {
+		pid = waitpid(WAIT_ANY, NULL, 0);
+	} while (pid != -1 || (pid == -1 && errno == EINTR));
+
+	proc_close(ps);
+}
+
+void
+proc_open(struct privsep *ps, struct privsep_proc *p,
+    struct privsep_proc *procs, size_t nproc)
+{
+	struct privsep_pipes	*pa, *pb;
+	int			 fds[2];
+	u_int			 i, j, src, proc;
+
+	if (p == NULL)
+		src = privsep_process; /* parent */
+	else
+		src = p->p_id;
+
+	/*
+	 * Open socket pairs for our peers
+	 */
+	for (proc = 0; proc < nproc; proc++) {
+		procs[proc].p_ps = ps;
+		procs[proc].p_env = ps->ps_env;
+
+		for (i = 0; i < ps->ps_instances[src]; i++) {
+			for (j = 0; j < ps->ps_instances[procs[proc].p_id];
+			    j++) {
+				pa = &ps->ps_pipes[src][i];
+				pb = &ps->ps_pipes[procs[proc].p_id][j];
+
+				/* Check if fds are already set by peer */
+				if (pa->pp_pipes[procs[proc].p_id][j] != -1)
+					continue;
+
+				if (socketpair(AF_UNIX, SOCK_STREAM,
+				    PF_UNSPEC, fds) == -1)
+					fatal("socketpair");
+
+				socket_set_blockmode(fds[0], BM_NONBLOCK);
+				socket_set_blockmode(fds[1], BM_NONBLOCK);
+
+				pa->pp_pipes[procs[proc].p_id][j] = fds[0];
+				pb->pp_pipes[src][i] = fds[1];
+			}
+		}
+	}
+}
+
+void
+proc_listen(struct privsep *ps, struct privsep_proc *procs, size_t nproc)
+{
+	u_int			 i, dst, src, n, m;
+	struct privsep_pipes	*pp;
+
+	/*
+	 * Close unused pipes
+	 */
+	for (src = 0; src < PROC_MAX; src++) {
+		for (n = 0; n < ps->ps_instances[src]; n++) {
+			/* Ingore current process */
+			if (src == (u_int)privsep_process &&
+			    n == ps->ps_instance)
+				continue;
+
+			pp = &ps->ps_pipes[src][n];
+
+			for (dst = 0; dst < PROC_MAX; dst++) {
+				if (src == dst)
+					continue;
+				for (m = 0; m < ps->ps_instances[dst]; m++) {
+					if (pp->pp_pipes[dst][m] == -1)
+						continue;
+
+					/* Close and invalidate fd */
+					close(pp->pp_pipes[dst][m]);
+					pp->pp_pipes[dst][m] = -1;
+				}
+			}
+		}
+	}
+
+	src = privsep_process;
+	ps->ps_pp = pp = &ps->ps_pipes[src][ps->ps_instance];
+
+	/*
+	 * Listen on appropriate pipes
+	 */
+	for (i = 0; i < nproc; i++) {
+		dst = procs[i].p_id;
+
+		if (src == dst)
+			fatal("proc_listen: cannot peer with oneself");
+
+		if ((ps->ps_ievs[dst] = calloc(ps->ps_instances[dst],
+		    sizeof(struct imsgev))) == NULL)
+			fatal("proc_open");
+
+		for (n = 0; n < ps->ps_instances[dst]; n++) {
+			if (pp->pp_pipes[dst][n] == -1)
+				continue;
+
+			imsg_init(&(ps->ps_ievs[dst][n].ibuf),
+			    pp->pp_pipes[dst][n]);
+			ps->ps_ievs[dst][n].handler = proc_dispatch;
+			ps->ps_ievs[dst][n].events = EV_READ;
+			ps->ps_ievs[dst][n].proc = &procs[i];
+			ps->ps_ievs[dst][n].data = &ps->ps_ievs[dst][n];
+			procs[i].p_instance = n;
+
+			event_set(&(ps->ps_ievs[dst][n].ev),
+			    ps->ps_ievs[dst][n].ibuf.fd,
+			    ps->ps_ievs[dst][n].events,
+			    ps->ps_ievs[dst][n].handler,
+			    ps->ps_ievs[dst][n].data);
+			event_add(&(ps->ps_ievs[dst][n].ev), NULL);
+		}
+	}
+}
+
+void
+proc_close(struct privsep *ps)
+{
+	u_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));
+			imsg_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("proc_sig_handler: unexpected signal");
+		/* NOTREACHED */
+	}
+}
+
+pid_t
+proc_run(struct privsep *ps, struct privsep_proc *p,
+    struct privsep_proc *procs, u_int nproc,
+    void (*init)(struct privsep *, struct privsep_proc *, void *), void *arg)
+{
+	pid_t			 pid;
+	struct passwd		*pw;
+	const char		*root;
+	struct control_sock	*rcs;
+	u_int			 n;
+
+	if (ps->ps_noaction)
+		return (0);
+
+	proc_open(ps, p, procs, nproc);
+
+	/* Fork child handlers */
+	switch (pid = fork()) {
+	case -1:
+		fatal("proc_run: cannot fork");
+	case 0:
+		/* Set the process group of the current process */
+		setpgid(0, 0);
+		break;
+	default:
+		return (pid);
+	}
+
+	pw = ps->ps_pw;
+
+	if (p->p_id == PROC_CONTROL && ps->ps_instance == 0) {
+		if (control_init(ps, &ps->ps_csock) == -1)
+			fatalx(p->p_title);
+		TAILQ_FOREACH(rcs, &ps->ps_rcsocks, cs_entry)
+			if (control_init(ps, rcs) == -1)
+				fatalx(p->p_title);
+	}
+
+	/* Change root directory */
+	if (p->p_chroot != NULL)
+		root = p->p_chroot;
+	else
+		root = pw->pw_dir;
+
+	if (chroot(root) == -1)
+		fatal("proc_run: chroot");
+	if (chdir("/") == -1)
+		fatal("proc_run: chdir(\"/\")");
+
+	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("proc_run: cannot drop privileges");
+
+	/* Fork child handlers */
+	for (n = 1; n < ps->ps_instances[p->p_id]; n++) {
+		if (fork() == 0) {
+			ps->ps_instance = p->p_instance = n;
+			break;
+		}
+	}
+
+#ifdef DEBUG
+	log_debug("%s: %s %d/%d, pid %d", __func__, p->p_title,
+	    ps->ps_instance + 1, ps->ps_instances[p->p_id], getpid());
+#endif
+
+	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_listen(ps, procs, nproc);
+
+	if (p->p_id == PROC_CONTROL && ps->ps_instance == 0) {
+		TAILQ_INIT(&ctl_conns);
+		if (control_listen(&ps->ps_csock) == -1)
+			fatalx(p->p_title);
+		TAILQ_FOREACH(rcs, &ps->ps_rcsocks, cs_entry)
+			if (control_listen(rcs) == -1)
+				fatalx(p->p_title);
+	}
+
+	if (init != NULL)
+		init(ps, p, arg);
+
+	event_dispatch();
+
+	proc_shutdown(p);
+
+	return (0);
+}
+
+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;
+
+	title = ps->ps_title[privsep_process];
+	ibuf = &iev->ibuf;
+
+	if (event & EV_READ) {
+		if ((n = imsg_read(ibuf)) == -1)
+			fatal(title);
+		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 (msgbuf_write(&ibuf->w) <= 0 && errno != EAGAIN)
+			fatal(title);
+	}
+
+	for (;;) {
+		if ((n = imsg_get(ibuf, &imsg)) == -1)
+			fatal(title);
+		if (n == 0)
+			break;
+
+#if DEBUG > 1
+		log_debug("%s: %s %d got imsg %d from %s %d",
+		    __func__, title, ps->ps_instance + 1,
+		    imsg.hdr.type, p->p_title, p->p_instance);
+#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_verbose(verbose);
+			break;
+		default:
+			log_warnx("%s: %s %d got invalid imsg %d from %s %d",
+			    __func__, title, ps->ps_instance + 1,
+			    imsg.hdr.type, p->p_title, p->p_instance);
+			fatalx(title);
+		}
+		imsg_free(&imsg);
+	}
+	imsg_event_add(iev);
+}
+
+/*
+ * imsg helper functions
+ */
+
+void
+imsg_event_add(struct imsgev *iev)
+{
+	if (iev->handler == NULL) {
+		imsg_flush(&iev->ibuf);
+		return;
+	}
+
+	iev->events = EV_READ;
+	if (iev->ibuf.w.queued)
+		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, u_int16_t type, u_int32_t peerid,
+    pid_t pid, int fd, void *data, u_int16_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, u_int16_t type, u_int32_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,
+    u_int16_t type, int fd, void *data, u_int16_t datalen)
+{
+	int	 m;
+
+	proc_range(ps, id, &n, &m);
+	for (; n < m; n++) {
+		if (imsg_compose_event(&ps->ps_ievs[id][n],
+		    type, -1, 0, fd, data, datalen) == -1)
+			return (-1);
+	}
+
+	return (0);
+}
+
+int
+proc_composev_imsg(struct privsep *ps, enum privsep_procid id, int n,
+    u_int16_t type, 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, -1, 0, fd, iov, iovcnt) == -1)
+			return (-1);
+
+	return (0);
+}
+
+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->fd, 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]);
+}