diff options
Diffstat (limited to 'usr.sbin/ypldap/ypldap_dns.c')
| -rw-r--r-- | usr.sbin/ypldap/ypldap_dns.c | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/usr.sbin/ypldap/ypldap_dns.c b/usr.sbin/ypldap/ypldap_dns.c new file mode 100644 index 0000000..507253c --- /dev/null +++ b/usr.sbin/ypldap/ypldap_dns.c @@ -0,0 +1,254 @@ +/* $OpenBSD: ypldap_dns.c,v 1.8 2015/01/16 06:40:22 deraadt Exp $ */ +/* $FreeBSD$ */ + +/* + * Copyright (c) 2003-2008 Henning Brauer <henning@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 MIND, 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/param.h> +#include <sys/socket.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/tree.h> +#include <sys/queue.h> + +#include <netinet/in.h> +#include <arpa/nameser.h> + +#include <netdb.h> +#include <pwd.h> +#include <errno.h> +#include <event.h> +#include <resolv.h> +#include <poll.h> +#include <signal.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <limits.h> + +#include "ypldap.h" + +volatile sig_atomic_t quit_dns = 0; +struct imsgev *iev_dns; + +void dns_dispatch_imsg(int, short, void *); +void dns_sig_handler(int, short, void *); +void dns_shutdown(void); +int host_dns(const char *s, struct ypldap_addr **hn); + +void +dns_sig_handler(int sig, short event, void *p) +{ + switch (sig) { + case SIGINT: + case SIGTERM: + dns_shutdown(); + break; + default: + fatalx("unexpected signal"); + } +} + +void +dns_shutdown(void) +{ + log_info("dns engine exiting"); + _exit(0); +} + +pid_t +ypldap_dns(int pipe_ntp[2], struct passwd *pw) +{ + pid_t pid; + struct event ev_sigint; + struct event ev_sigterm; + struct event ev_sighup; + struct env env; + + switch (pid = fork()) { + case -1: + fatal("cannot fork"); + break; + case 0: + break; + default: + return (pid); + } + + setproctitle("dns engine"); + close(pipe_ntp[0]); + + 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("can't drop privileges"); + endservent(); + + event_init(); + signal_set(&ev_sigint, SIGINT, dns_sig_handler, NULL); + signal_set(&ev_sigterm, SIGTERM, dns_sig_handler, NULL); + signal_set(&ev_sighup, SIGHUP, dns_sig_handler, NULL); + signal_add(&ev_sigint, NULL); + signal_add(&ev_sigterm, NULL); + signal_add(&ev_sighup, NULL); + + if ((env.sc_iev = calloc(1, sizeof(*env.sc_iev))) == NULL) + fatal(NULL); + + env.sc_iev->events = EV_READ; + env.sc_iev->data = &env; + imsg_init(&env.sc_iev->ibuf, pipe_ntp[1]); + env.sc_iev->handler = dns_dispatch_imsg; + event_set(&env.sc_iev->ev, env.sc_iev->ibuf.fd, env.sc_iev->events, + env.sc_iev->handler, &env); + event_add(&env.sc_iev->ev, NULL); + + event_dispatch(); + dns_shutdown(); + + return (0); +} + +void +dns_dispatch_imsg(int fd, short events, void *p) +{ + struct imsg imsg; + int n, cnt; + char *name; + struct ypldap_addr *h, *hn; + struct ibuf *buf; + struct env *env = p; + struct imsgev *iev = env->sc_iev; + struct imsgbuf *ibuf = &iev->ibuf; + int shut = 0; + + if ((events & (EV_READ | EV_WRITE)) == 0) + fatalx("unknown event"); + + if (events & EV_READ) { + if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN) + fatal("imsg_read error"); + if (n == 0) + shut = 1; + } + if (events & EV_WRITE) { + if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN) + fatal("msgbuf_write"); + if (n == 0) + shut = 1; + goto done; + } + + for (;;) { + if ((n = imsg_get(ibuf, &imsg)) == -1) + fatal("client_dispatch_imsg: imsg_get error"); + if (n == 0) + break; + + switch (imsg.hdr.type) { + case IMSG_HOST_DNS: + name = imsg.data; + if (imsg.hdr.len < 1 + IMSG_HEADER_SIZE) + fatalx("invalid IMSG_HOST_DNS received"); + imsg.hdr.len -= 1 + IMSG_HEADER_SIZE; + if (name[imsg.hdr.len] != '\0' || + strlen(name) != imsg.hdr.len) + fatalx("invalid IMSG_HOST_DNS received"); + if ((cnt = host_dns(name, &hn)) == -1) + break; + buf = imsg_create(ibuf, IMSG_HOST_DNS, + imsg.hdr.peerid, 0, + cnt * sizeof(struct sockaddr_storage)); + if (buf == NULL) + break; + if (cnt > 0) { + h = hn; + while (h != NULL) { + imsg_add(buf, &h->ss, sizeof(h->ss)); + hn = h->next; + free(h); + h = hn; + } + } + + imsg_close(ibuf, buf); + break; + default: + break; + } + imsg_free(&imsg); + } + +done: + if (!shut) + imsg_event_add(iev); + else { + /* this pipe is dead, so remove the event handler */ + event_del(&iev->ev); + event_loopexit(NULL); + } +} + +int +host_dns(const char *s, struct ypldap_addr **hn) +{ + struct addrinfo hints, *res0, *res; + int error, cnt = 0; + struct sockaddr_in *sa_in; + struct sockaddr_in6 *sa_in6; + struct ypldap_addr *h, *hh = NULL; + + bzero(&hints, sizeof(hints)); + hints.ai_family = PF_UNSPEC; + hints.ai_socktype = SOCK_DGRAM; /* DUMMY */ + error = getaddrinfo(s, NULL, &hints, &res0); + if (error == EAI_AGAIN || error == EAI_NONAME) + return (0); + if (error) { + log_warnx("could not parse \"%s\": %s", s, + gai_strerror(error)); + return (-1); + } + + for (res = res0; res && cnt < MAX_SERVERS_DNS; res = res->ai_next) { + if (res->ai_family != AF_INET && + res->ai_family != AF_INET6) + continue; + if ((h = calloc(1, sizeof(struct ypldap_addr))) == NULL) + fatal(NULL); + h->ss.ss_family = res->ai_family; + if (res->ai_family == AF_INET) { + sa_in = (struct sockaddr_in *)&h->ss; + sa_in->sin_len = sizeof(struct sockaddr_in); + sa_in->sin_addr.s_addr = ((struct sockaddr_in *) + res->ai_addr)->sin_addr.s_addr; + } else { + sa_in6 = (struct sockaddr_in6 *)&h->ss; + sa_in6->sin6_len = sizeof(struct sockaddr_in6); + memcpy(&sa_in6->sin6_addr, &((struct sockaddr_in6 *) + res->ai_addr)->sin6_addr, sizeof(struct in6_addr)); + } + + h->next = hh; + hh = h; + cnt++; + } + freeaddrinfo(res0); + + *hn = hh; + return (cnt); +} |
