diff options
author | 2016-09-14 13:46:51 +0000 | |
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committer | 2016-09-14 13:46:51 +0000 | |
commit | 9670b02bdf2c9449c661bab7e8693bdfb70d2e89 (patch) | |
tree | 178fd40470b5376fa603e58da9eef7a4330d5f18 /usr.sbin/switchd/proc.c | |
parent | add an is_local-file method for later signature (diff) | |
download | wireguard-openbsd-9670b02bdf2c9449c661bab7e8693bdfb70d2e89.tar.xz wireguard-openbsd-9670b02bdf2c9449c661bab7e8693bdfb70d2e89.zip |
Teach switchd(8) how to fork+exec.
Note: this daemon has the -Wcast-qual compilation flag which trigger a
warning that wasn't enable in httpd(8) or relayd(8). This will be fixed
in a next diff and then synchronized with other daemons.
ok reyk@
Diffstat (limited to 'usr.sbin/switchd/proc.c')
-rw-r--r-- | usr.sbin/switchd/proc.c | 520 |
1 files changed, 334 insertions, 186 deletions
diff --git a/usr.sbin/switchd/proc.c b/usr.sbin/switchd/proc.c index fb3dfcfa50c..5e3f1b68c5e 100644 --- a/usr.sbin/switchd/proc.c +++ b/usr.sbin/switchd/proc.c @@ -1,4 +1,4 @@ -/* $OpenBSD: proc.c,v 1.1 2016/07/19 16:54:26 reyk Exp $ */ +/* $OpenBSD: proc.c,v 1.2 2016/09/14 13:46:51 rzalamena Exp $ */ /* * Copyright (c) 2010 - 2014 Reyk Floeter <reyk@openbsd.org> @@ -34,8 +34,14 @@ #include "proc.h" -void proc_open(struct privsep *, struct privsep_proc *, - struct privsep_proc *, size_t); +void proc_exec(struct privsep *, struct privsep_proc *, unsigned int, + int, char **); +void proc_connectpeer(struct privsep *, enum privsep_procid, int, + struct privsep_pipes *); +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 *); int proc_ispeer(struct privsep_proc *, unsigned int, enum privsep_procid); void proc_shutdown(struct privsep_proc *); @@ -55,12 +61,264 @@ proc_ispeer(struct privsep_proc *procs, unsigned int nproc, return (0); } +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 *) 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. */ + dup2(fd, PROC_PARENT_SOCK_FILENO); + + execvp(argv[0], nargv); + fatal("%s: execvp", __func__); + break; + default: + /* Close child end. */ + close(fd); + break; + } + } + } + free(nargv); +} + +void +proc_connectpeer(struct privsep *ps, enum privsep_procid id, int inst, + struct privsep_pipes *pp) +{ + unsigned int i, j; + struct privsep_fd pf; + + for (i = 0; i < PROC_MAX; i++) { + /* Parent is already connected with everyone. */ + if (i == PROC_PARENT) + continue; + + for (j = 0; j < ps->ps_instances[i]; j++) { + /* Don't send socket to child itself. */ + if (i == (unsigned int)id && + j == (unsigned int)inst) + continue; + if (pp->pp_pipes[i][j] == -1) + continue; + + pf.pf_procid = i; + pf.pf_instance = j; + proc_compose_imsg(ps, id, inst, IMSG_CTL_PROCFD, + -1, pp->pp_pipes[i][j], &pf, sizeof(pf)); + pp->pp_pipes[i][j] = -1; + } + } +} + +/* Inter-connect all process except with ourself. */ +void +proc_connect(struct privsep *ps) +{ + unsigned int src, i, j; + struct privsep_pipes *pp; + struct imsgev *iev; + + /* Listen on appropriate pipes. */ + src = privsep_process; + pp = &ps->ps_pipes[src][ps->ps_instance]; + + for (i = 0; i < PROC_MAX; i++) { + /* Don't listen to ourself. */ + if (i == src) + continue; + + for (j = 0; j < ps->ps_instances[i]; j++) { + if (pp->pp_pipes[i][j] == -1) + continue; + + iev = &ps->ps_ievs[i][j]; + imsg_init(&iev->ibuf, pp->pp_pipes[i][j]); + event_set(&iev->ev, iev->ibuf.fd, iev->events, + iev->handler, iev->data); + event_add(&iev->ev, NULL); + } + } + + /* Exchange pipes between process. */ + for (i = 0; i < PROC_MAX; i++) { + /* Parent is already connected with everyone. */ + if (i == PROC_PARENT) + continue; + + for (j = 0; j < ps->ps_instances[i]; j++) + proc_connectpeer(ps, i, j, &ps->ps_pipes[i][j]); + } +} + void -proc_init(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc) +proc_init(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc, + int argc, char **argv, enum privsep_procid proc_id) { - unsigned int i, j, src, dst; + struct privsep_proc *p = NULL; + unsigned int proc; + unsigned int src, dst; + + if (proc_id == PROC_PARENT) { + privsep_process = PROC_PARENT; + proc_setup(ps, procs, nproc); + + /* Open socketpair()s for everyone. */ + for (src = 0; src < PROC_MAX; src++) + for (dst = 0; dst < PROC_MAX; dst++) + proc_open(ps, src, dst); + + /* 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]; + imsg_init(&iev->ibuf, fd); + 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; + procs[src].p_env = ps->ps_env; + 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(__func__); + + /* With this set up, we are ready to call imsg_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) * @@ -76,183 +334,93 @@ proc_init(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc) */ for (src = 0; src < PROC_MAX; src++) { /* Allocate destination array for each process */ - if ((ps->ps_pipes[src] = calloc(ps->ps_ninstances, + if ((ps->ps_pipes[src] = calloc(ps->ps_instances[src], sizeof(struct privsep_pipes))) == NULL) - fatal("proc_init: calloc"); + fatal("%s: calloc", __func__); - for (i = 0; i < ps->ps_ninstances; i++) { + 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_ninstances, + calloc(ps->ps_instances[dst], sizeof(int))) == NULL) - fatal("proc_init: calloc"); + fatal("%s: calloc", __func__); /* Mark fd as unused */ - for (j = 0; j < ps->ps_ninstances; j++) + for (j = 0; j < ps->ps_instances[dst]; 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]); + ps->ps_pp = &ps->ps_pipes[privsep_process][ps->ps_instance]; } void proc_kill(struct privsep *ps) { + char *cause; pid_t pid; - unsigned int i; + int len, status; 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); - } + proc_close(ps); do { - pid = waitpid(WAIT_ANY, NULL, 0); - } while (pid != -1 || (pid == -1 && errno == EINTR)); + pid = waitpid(WAIT_ANY, &status, 0); + if (pid <= 0) + continue; - proc_close(ps); + 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 || (pid == -1 && errno == EINTR)); } void -proc_open(struct privsep *ps, struct privsep_proc *p, - struct privsep_proc *procs, size_t nproc) +proc_open(struct privsep *ps, int src, int dst) { struct privsep_pipes *pa, *pb; int fds[2]; - unsigned 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; - if (procs[proc].p_cb == NULL) - procs[proc].p_cb = proc_dispatch_null; - - 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 | SOCK_NONBLOCK, - PF_UNSPEC, fds) == -1) - fatal("socketpair"); - - pa->pp_pipes[procs[proc].p_id][j] = fds[0]; - pb->pp_pipes[src][i] = fds[1]; - } - } - } -} + unsigned int i, j; -void -proc_listen(struct privsep *ps, struct privsep_proc *procs, size_t nproc) -{ - unsigned 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 == (unsigned int)privsep_process && - n == ps->ps_instance) + 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; - 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) + pa = &ps->ps_pipes[src][i]; + pb = &ps->ps_pipes[dst][j]; + if (pb->pp_pipes[dst][j] != -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); + if (socketpair(AF_UNIX, + SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, + PF_UNSPEC, fds) == -1) + fatal(__func__); + + pa->pp_pipes[dst][j] = fds[0]; + pb->pp_pipes[src][i] = fds[1]; } } } @@ -301,7 +469,7 @@ proc_shutdown(struct privsep_proc *p) log_info("%s exiting, pid %d", p->p_title, getpid()); - _exit(0); + exit(0); } void @@ -326,37 +494,22 @@ proc_sig_handler(int sig, short event, void *arg) } } -pid_t +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) { - pid_t pid; - struct passwd *pw; + struct passwd *pw = ps->ps_pw; const char *root; struct control_sock *rcs; - unsigned int n; if (ps->ps_noaction) - return (0); - - proc_open(ps, p, procs, nproc); + exit(0); - /* Fork child handlers */ - switch (pid = fork()) { - case -1: - fatal("proc_run: cannot fork"); - case 0: - log_procinit(p->p_title); - - /* Set the process group of the current process */ - setpgid(0, 0); - break; - default: - return (pid); - } + log_procinit(p->p_title); - pw = ps->ps_pw; + /* Set the process group of the current process */ + setpgid(0, 0); if (p->p_id == PROC_CONTROL && ps->ps_instance == 0) { if (control_init(ps, &ps->ps_csock) == -1) @@ -386,19 +539,6 @@ proc_run(struct privsep *ps, struct privsep_proc *p, 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); @@ -415,8 +555,8 @@ proc_run(struct privsep *ps, struct privsep_proc *p, signal_add(&ps->ps_evsigpipe, NULL); signal_add(&ps->ps_evsigusr1, NULL); - proc_listen(ps, procs, nproc); - + 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) { TAILQ_INIT(&ctl_conns); if (control_listen(&ps->ps_csock) == -1) @@ -426,14 +566,15 @@ proc_run(struct privsep *ps, struct privsep_proc *p, fatalx(__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); - - return (0); } void @@ -447,6 +588,7 @@ proc_dispatch(int fd, short event, void *arg) ssize_t n; int verbose; const char *title; + struct privsep_fd pf; title = ps->ps_title[privsep_process]; ibuf = &iev->ibuf; @@ -476,7 +618,7 @@ proc_dispatch(int fd, short event, void *arg) #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, p->p_instance); + imsg.hdr.type, imsg.hdr.peerid, p->p_title, imsg.hdr.pid); #endif /* @@ -497,12 +639,18 @@ proc_dispatch(int fd, short event, void *arg) memcpy(&verbose, imsg.data, sizeof(verbose)); log_verbose(verbose); break; + case IMSG_CTL_PROCFD: + IMSG_SIZE_CHECK(&imsg, &pf); + memcpy(&pf, imsg.data, sizeof(pf)); + proc_accept(ps, imsg.fd, pf.pf_procid, + pf.pf_instance); + break; default: log_warnx("%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, p->p_instance); + p->p_title, imsg.hdr.pid); fatalx(__func__); } imsg_free(&imsg); @@ -585,7 +733,7 @@ proc_compose_imsg(struct privsep *ps, enum privsep_procid id, int n, proc_range(ps, id, &n, &m); for (; n < m; n++) { if (imsg_compose_event(&ps->ps_ievs[id][n], - type, peerid, 0, fd, data, datalen) == -1) + type, peerid, ps->ps_instance + 1, fd, data, datalen) == -1) return (-1); } @@ -608,7 +756,7 @@ proc_composev_imsg(struct privsep *ps, enum privsep_procid id, int n, proc_range(ps, id, &n, &m); for (; n < m; n++) if (imsg_composev_event(&ps->ps_ievs[id][n], - type, peerid, 0, fd, iov, iovcnt) == -1) + type, peerid, ps->ps_instance + 1, fd, iov, iovcnt) == -1) return (-1); return (0); |