/* $OpenBSD: proc.c,v 1.7 2014/02/14 10:21:00 benno Exp $ */ /* * Copyright (c) 2010,2011 Reyk Floeter * Copyright (c) 2008 Pierre-Yves Ritschard * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "relayd.h" void proc_setup(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 *p, u_int nproc, enum privsep_procid type) { u_int i; for (i = 0; i < nproc; i++) if (p[i].p_id == type) return (1); return (0); } void proc_init(struct privsep *ps, struct privsep_proc *p, u_int nproc) { u_int i; /* * Called from parent */ privsep_process = PROC_PARENT; ps->ps_instances[PROC_PARENT] = 1; ps->ps_title[PROC_PARENT] = "parent"; ps->ps_pid[PROC_PARENT] = getpid(); for (i = 0; i < nproc; i++) { /* Default to 1 process instance */ if (ps->ps_instances[p[i].p_id] < 1) ps->ps_instances[p[i].p_id] = 1; ps->ps_title[p[i].p_id] = p[i].p_title; } proc_setup(ps); /* Engage! */ for (i = 0; i < nproc; i++) ps->ps_pid[p[i].p_id] = (*p[i].p_init)(ps, &p[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_clear(ps, 1); } void proc_setup(struct privsep *ps) { int i, j, n, count, sockpair[2]; for (i = 0; i < PROC_MAX; i++) for (j = 0; j < PROC_MAX; j++) { /* * find out how many instances of this peer there are. */ if (i >= j || ps->ps_instances[i] == 0 || ps->ps_instances[j] == 0) continue; if (ps->ps_instances[i] > 1 && ps->ps_instances[j] > 1) fatalx("N:M peering not supported"); count = ps->ps_instances[i] * ps->ps_instances[j]; if ((ps->ps_pipes[i][j] = calloc(count, sizeof(int))) == NULL || (ps->ps_pipes[j][i] = calloc(count, sizeof(int))) == NULL) fatal(NULL); for (n = 0; n < count; n++) { if (ps->ps_noaction) continue; if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, sockpair) == -1) fatal("socketpair"); ps->ps_pipes[i][j][n] = sockpair[0]; ps->ps_pipes[j][i][n] = sockpair[1]; socket_set_blockmode( ps->ps_pipes[i][j][n], BM_NONBLOCK); socket_set_blockmode( ps->ps_pipes[j][i][n], BM_NONBLOCK); } } } void proc_config(struct privsep *ps, struct privsep_proc *p, u_int nproc) { u_int i, j, src, dst, count, n, instance; src = privsep_process; /* * close unused pipes */ for (i = 0; i < PROC_MAX; i++) { for (j = 0; j < PROC_MAX; j++) { if (i == j || ps->ps_instances[i] == 0 || ps->ps_instances[j] == 0) continue; count = ps->ps_instances[i] * ps->ps_instances[j]; for (n = 0; n < count; n++) { instance = ps->ps_instances[i] > 1 ? n : 0; if (i == src && proc_ispeer(p, nproc, j) && ps->ps_instance == instance) continue; if (!ps->ps_noaction) close(ps->ps_pipes[i][j][n]); ps->ps_pipes[i][j][n] = -1; } } } /* * listen on appropriate pipes */ for (i = 0; i < nproc; i++) { dst = p[i].p_id; p[i].p_ps = ps; p[i].p_env = ps->ps_env; if (src == dst) fatal("proc_config: cannot peer with oneself"); count = ps->ps_instances[src] * ps->ps_instances[dst]; if ((ps->ps_ievs[dst] = calloc(count, sizeof(struct imsgev))) == NULL) fatal("proc_config"); for (n = 0; n < count; n++) { if (ps->ps_pipes[src][dst][n] == -1) continue; imsg_init(&(ps->ps_ievs[dst][n].ibuf), ps->ps_pipes[src][dst][n]); ps->ps_ievs[dst][n].handler = proc_dispatch; ps->ps_ievs[dst][n].events = EV_READ; ps->ps_ievs[dst][n].proc = &p[i]; ps->ps_ievs[dst][n].data = &ps->ps_ievs[dst][n]; p[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_clear(struct privsep *ps, int purge) { u_int src = privsep_process, dst, n, count; if (ps == NULL) return; for (dst = 0; dst < PROC_MAX; dst++) { if (src == dst || ps->ps_ievs[dst] == NULL) continue; count = ps->ps_instances[src] * ps->ps_instances[dst]; for (n = 0; n < count; n++) { if (ps->ps_pipes[src][dst][n] == -1) continue; if (purge) { event_del(&(ps->ps_ievs[dst][n].ev)); imsg_clear(&(ps->ps_ievs[dst][n].ibuf)); close(ps->ps_pipes[src][dst][n]); } else imsg_flush(&(ps->ps_ievs[dst][n].ibuf)); } if (purge) 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_clear(ps, 1); 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: /* 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; u_int32_t seed[256]; u_int n; if (ps->ps_noaction) return (0); switch (pid = fork()) { case -1: fatal("run_proc: cannot fork"); case 0: /* Set the process group of the current process */ setpgrp(0, getpid()); break; default: return (pid); } pw = ps->ps_pw; if (p->p_id == PROC_CONTROL) { if (control_init(ps, &ps->ps_csock) == -1) fatalx(p->p_title); } /* Change root directory */ if (p->p_chroot != NULL) root = p->p_chroot; else root = pw->pw_dir; #ifndef DEBUG if (chroot(root) == -1) fatal("run_proc: chroot"); if (chdir("/") == -1) fatal("run_proc: chdir(\"/\")"); #else #warning disabling privilege revocation and chroot in DEBUG MODE if (p->p_chroot != NULL) { if (chroot(root) == -1) fatal("run_proc: chroot"); if (chdir("/") == -1) fatal("run_proc: chdir(\"/\")"); } #endif privsep_process = p->p_id; setproctitle("%s", p->p_title); #ifndef DEBUG 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("run_proc: cannot drop privileges"); #endif /* 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_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); proc_config(ps, procs, nproc); arc4random_buf(seed, sizeof(seed)); RAND_seed(seed, sizeof(seed)); 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); } 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) == -1 && 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) { /* * -1 means that the current process is * N:1 - one of many processes connected to a single peer, * so find the right slot of the peer. * 1:N - a single process connected to many peers, * so find the range of slots of all peers. */ if (ps->ps_instances[privsep_process] <= ps->ps_instances[id]) { *n = 0; *m = ps->ps_instances[id]; return; } *n = ps->ps_instance; *m = ps->ps_instance + 1; } 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); }