diff options
Diffstat (limited to 'sbin/unwind/captiveportal.c')
| -rw-r--r-- | sbin/unwind/captiveportal.c | 676 |
1 files changed, 0 insertions, 676 deletions
diff --git a/sbin/unwind/captiveportal.c b/sbin/unwind/captiveportal.c deleted file mode 100644 index 0c7b0c1f207..00000000000 --- a/sbin/unwind/captiveportal.c +++ /dev/null @@ -1,676 +0,0 @@ -/* $OpenBSD: captiveportal.c,v 1.12 2019/05/14 14:51:31 florian Exp $ */ - -/* - * Copyright (c) 2018 Florian Obser <florian@openbsd.org> - * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org> - * Copyright (c) 2004 Esben Norby <norby@openbsd.org> - * Copyright (c) 2003, 2004 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 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/syslog.h> -#include <sys/uio.h> - -#include <netinet/in.h> -#include <net/if.h> -#include <net/route.h> - -#include <ctype.h> -#include <errno.h> -#include <event.h> -#include <imsg.h> -#include <limits.h> -#include <netdb.h> -#include <pwd.h> -#include <signal.h> -#include <stdint.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <time.h> -#include <unistd.h> -#include <vis.h> - -#include "log.h" -#include "unwind.h" -#include "captiveportal.h" - -enum http_global_state { - IDLE, - READING -}; - -enum http_state { - INIT, - SENT_QUERY, - HEADER_READ -}; - -struct http_ctx { - TAILQ_ENTRY(http_ctx) entry; - struct event ev; - int fd; - enum http_state state; - char *buf; - size_t bufsz; - int status; - int content_length; -}; - -__dead void captiveportal_shutdown(void); -void captiveportal_sig_handler(int, short, void *); -void captiveportal_startup(void); -void http_callback(int, short, void *); -int parse_http_header(struct http_ctx *); -void check_http_body(struct http_ctx *ctx); -void free_http_ctx(struct http_ctx *); -void close_other_http_contexts(struct http_ctx *); - -struct uw_conf *captiveportal_conf; -struct imsgev *iev_main; -struct imsgev *iev_resolver; -struct imsgev *iev_frontend; - -#define MAX_SERVERS_DNS 8 -enum http_global_state http_global_state = IDLE; -TAILQ_HEAD(, http_ctx) http_contexts; -int http_contexts_count; - -struct timeval tv = {5, 0}; - -void -captiveportal_sig_handler(int sig, short event, void *bula) -{ - /* - * Normal signal handler rules don't apply because libevent - * decouples for us. - */ - - switch (sig) { - case SIGINT: - case SIGTERM: - captiveportal_shutdown(); - default: - fatalx("unexpected signal"); - } -} - -void -captiveportal(int debug, int verbose) -{ - struct event ev_sigint, ev_sigterm; - struct passwd *pw; - - captiveportal_conf = config_new_empty(); - - log_init(debug, LOG_DAEMON); - log_setverbose(verbose); - - if ((pw = getpwnam(UNWIND_USER)) == NULL) - fatal("getpwnam"); - - if (chroot(pw->pw_dir) == -1) - fatal("chroot"); - if (chdir("/") == -1) - fatal("chdir(\"/\")"); - - uw_process = PROC_CAPTIVEPORTAL; - setproctitle("%s", log_procnames[uw_process]); - log_procinit(log_procnames[uw_process]); - - 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"); - - if (pledge("stdio recvfd", NULL) == -1) - fatal("pledge"); - - event_init(); - - /* Setup signal handler. */ - signal_set(&ev_sigint, SIGINT, captiveportal_sig_handler, NULL); - signal_set(&ev_sigterm, SIGTERM, captiveportal_sig_handler, NULL); - signal_add(&ev_sigint, NULL); - signal_add(&ev_sigterm, NULL); - signal(SIGPIPE, SIG_IGN); - signal(SIGHUP, SIG_IGN); - - /* Setup pipe and event handler to the parent process. */ - if ((iev_main = malloc(sizeof(struct imsgev))) == NULL) - fatal(NULL); - imsg_init(&iev_main->ibuf, 3); - iev_main->handler = captiveportal_dispatch_main; - iev_main->events = EV_READ; - event_set(&iev_main->ev, iev_main->ibuf.fd, iev_main->events, - iev_main->handler, iev_main); - event_add(&iev_main->ev, NULL); - - TAILQ_INIT(&http_contexts); - - event_dispatch(); - - captiveportal_shutdown(); -} - -__dead void -captiveportal_shutdown(void) -{ - /* Close pipes. */ - msgbuf_write(&iev_resolver->ibuf.w); - msgbuf_clear(&iev_resolver->ibuf.w); - close(iev_resolver->ibuf.fd); - msgbuf_write(&iev_frontend->ibuf.w); - msgbuf_clear(&iev_frontend->ibuf.w); - close(iev_frontend->ibuf.fd); - msgbuf_write(&iev_main->ibuf.w); - msgbuf_clear(&iev_main->ibuf.w); - close(iev_main->ibuf.fd); - - config_clear(captiveportal_conf); - - free(iev_resolver); - free(iev_frontend); - free(iev_main); - - log_info("captiveportal exiting"); - exit(0); -} - -int -captiveportal_imsg_compose_main(int type, pid_t pid, void *data, - uint16_t datalen) -{ - return (imsg_compose_event(iev_main, type, 0, pid, -1, data, datalen)); -} - -int -captiveportal_imsg_compose_resolver(int type, pid_t pid, void *data, - uint16_t datalen) -{ - return (imsg_compose_event(iev_resolver, type, 0, pid, -1, data, - datalen)); -} - -int -captiveportal_imsg_compose_frontend(int type, pid_t pid, void *data, - uint16_t datalen) -{ - return (imsg_compose_event(iev_frontend, type, 0, pid, -1, data, - datalen)); -} - -void -captiveportal_dispatch_main(int fd, short event, void *bula) -{ - static struct uw_conf *nconf; - struct imsg imsg; - struct imsgev *iev = bula; - struct imsgbuf *ibuf = &iev->ibuf; - struct http_ctx *ctx; - int n, shut = 0; - - if (event & EV_READ) { - if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN) - fatal("imsg_read error"); - if (n == 0) /* Connection closed. */ - shut = 1; - } - if (event & EV_WRITE) { - if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN) - fatal("msgbuf_write"); - if (n == 0) /* Connection closed. */ - shut = 1; - } - - for (;;) { - if ((n = imsg_get(ibuf, &imsg)) == -1) - fatal("%s: imsg_get error", __func__); - if (n == 0) /* No more messages. */ - break; - - switch (imsg.hdr.type) { - case IMSG_SOCKET_IPC_RESOLVER: - /* - * Setup pipe and event handler to the resolver - * process. - */ - if (iev_resolver) { - fatalx("%s: received unexpected imsg fd " - "to captiveportal", __func__); - break; - } - if ((fd = imsg.fd) == -1) { - fatalx("%s: expected to receive imsg fd to " - "captiveportal but didn't receive any", - __func__); - break; - } - - iev_resolver = malloc(sizeof(struct imsgev)); - if (iev_resolver == NULL) - fatal(NULL); - - imsg_init(&iev_resolver->ibuf, fd); - iev_resolver->handler = captiveportal_dispatch_resolver; - iev_resolver->events = EV_READ; - - event_set(&iev_resolver->ev, iev_resolver->ibuf.fd, - iev_resolver->events, iev_resolver->handler, - iev_resolver); - event_add(&iev_resolver->ev, NULL); - break; - case IMSG_SOCKET_IPC_FRONTEND: - /* - * Setup pipe and event handler to the frontend - * process. - */ - if (iev_frontend) { - fatalx("%s: received unexpected imsg fd " - "to frontend", __func__); - break; - } - if ((fd = imsg.fd) == -1) { - fatalx("%s: expected to receive imsg fd to " - "frontend but didn't receive any", - __func__); - break; - } - - iev_frontend = malloc(sizeof(struct imsgev)); - if (iev_frontend == NULL) - fatal(NULL); - - imsg_init(&iev_frontend->ibuf, fd); - iev_frontend->handler = captiveportal_dispatch_frontend; - iev_frontend->events = EV_READ; - - event_set(&iev_frontend->ev, iev_frontend->ibuf.fd, - iev_frontend->events, iev_frontend->handler, - iev_frontend); - event_add(&iev_frontend->ev, NULL); - break; - case IMSG_RECONF_CONF: - case IMSG_RECONF_CAPTIVE_PORTAL_HOST: - case IMSG_RECONF_CAPTIVE_PORTAL_PATH: - case IMSG_RECONF_CAPTIVE_PORTAL_EXPECTED_RESPONSE: - case IMSG_RECONF_BLOCKLIST_FILE: - case IMSG_RECONF_FORWARDER: - case IMSG_RECONF_DOT_FORWARDER: - imsg_receive_config(&imsg, &nconf); - break; - case IMSG_RECONF_END: - if (nconf == NULL) - fatalx("%s: IMSG_RECONF_END without " - "IMSG_RECONF_CONF", __func__); - merge_config(captiveportal_conf, nconf); - nconf = NULL; - break; - case IMSG_HTTPSOCK: - if ((fd = imsg.fd) == -1) { - fatalx("%s: expected to receive imsg fd to " - "captiveportal but didn't receive any", - __func__); - break; - } - - if (http_global_state == READING || - http_contexts_count >= MAX_SERVERS_DNS) { - /* don't try more servers */ - close(fd); - break; - } - - if ((ctx = malloc(sizeof(*ctx))) == NULL) { - close(fd); - break; - } - - ctx->state = INIT; - ctx->fd = fd; - ctx->bufsz = 0; - ctx->buf = NULL; - ctx->status = -1; - ctx->content_length = -1; - - event_set(&ctx->ev, fd, EV_READ | EV_WRITE | - EV_PERSIST, http_callback, ctx); - event_add(&ctx->ev, &tv); - - TAILQ_INSERT_TAIL(&http_contexts, ctx, entry); - - http_contexts_count++; - - break; - default: - log_debug("%s: error handling imsg %d", __func__, - imsg.hdr.type); - break; - } - imsg_free(&imsg); - } - if (!shut) - imsg_event_add(iev); - else { - /* This pipe is dead. Remove its event handler. */ - event_del(&iev->ev); - event_loopexit(NULL); - } -} - -void -captiveportal_dispatch_resolver(int fd, short event, void *bula) -{ - struct imsgev *iev = bula; - struct imsgbuf *ibuf = &iev->ibuf; - struct imsg imsg; - int n, shut = 0; - - if (event & EV_READ) { - if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN) - fatal("imsg_read error"); - if (n == 0) /* Connection closed. */ - shut = 1; - } - if (event & EV_WRITE) { - if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN) - fatal("msgbuf_write"); - if (n == 0) /* Connection closed. */ - shut = 1; - } - - for (;;) { - if ((n = imsg_get(ibuf, &imsg)) == -1) - fatal("%s: imsg_get error", __func__); - if (n == 0) /* No more messages. */ - break; - - switch (imsg.hdr.type) { - default: - log_debug("%s: error handling imsg %d", __func__, - imsg.hdr.type); - break; - } - imsg_free(&imsg); - } - if (!shut) - imsg_event_add(iev); - else { - /* This pipe is dead. Remove its event handler. */ - event_del(&iev->ev); - event_loopexit(NULL); - } -} - -void -captiveportal_dispatch_frontend(int fd, short event, void *bula) -{ - struct imsgev *iev = bula; - struct imsgbuf *ibuf = &iev->ibuf; - struct imsg imsg; - int n, verbose, shut = 0; - - if (event & EV_READ) { - if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN) - fatal("imsg_read error"); - if (n == 0) /* Connection closed. */ - shut = 1; - } - if (event & EV_WRITE) { - if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN) - fatal("msgbuf_write"); - if (n == 0) /* Connection closed. */ - shut = 1; - } - - for (;;) { - if ((n = imsg_get(ibuf, &imsg)) == -1) - fatal("%s: imsg_get error", __func__); - if (n == 0) /* No more messages. */ - break; - - switch (imsg.hdr.type) { - case IMSG_CTL_LOG_VERBOSE: - if (IMSG_DATA_SIZE(imsg) != sizeof(verbose)) - fatalx("%s: IMSG_CTL_LOG_VERBOSE wrong length: " - "%lu", __func__, IMSG_DATA_SIZE(imsg)); - memcpy(&verbose, imsg.data, sizeof(verbose)); - log_setverbose(verbose); - break; - default: - log_debug("%s: error handling imsg %d", __func__, - imsg.hdr.type); - break; - } - imsg_free(&imsg); - } - if (!shut) - imsg_event_add(iev); - else { - /* This pipe is dead. Remove its event handler. */ - event_del(&iev->ev); - event_loopexit(NULL); - } -} - -void -http_callback(int fd, short events, void *arg) -{ - struct http_ctx *ctx; - ssize_t n; - char *query, buf[512], *vis_str, *p, *ep; - - ctx = (struct http_ctx *)arg; - - if (events & EV_TIMEOUT) { - log_debug("%s: TIMEOUT", __func__); - goto err; - } - - if (events & EV_READ) { - if ((n = read(fd, buf, sizeof(buf))) == -1) { - if (errno == EAGAIN || errno == EINTR) - return; - else { - log_warn("%s: read", __func__); - if (http_global_state == READING) - http_global_state = IDLE; - goto err; - } - } - - if (http_contexts_count > 1) - close_other_http_contexts(ctx); - http_global_state = READING; - - if (n == 0) { - check_http_body(ctx); - return; - } - p = recallocarray(ctx->buf, ctx->bufsz, ctx->bufsz + n, 1); - if (p == NULL) { - log_warn("%s", __func__); - goto err; - } - ctx->buf = p; - memcpy(ctx->buf + ctx->bufsz, buf, n); - ctx->bufsz += n; - - if (ctx->state == HEADER_READ && ctx->content_length != -1 && - ctx->bufsz >= (size_t)ctx->content_length) { - check_http_body(ctx); - return; - } - - if (ctx->state == SENT_QUERY) { - ep = memmem(ctx->buf, ctx->bufsz, "\r\n\r\n", 4); - if (ep != NULL) { - ctx->state = HEADER_READ; - *ep = '\0'; - if (strlen(ctx->buf) != (uintptr_t) - (ep - ctx->buf)) { - log_warnx("binary data in header"); - goto err; - } - stravis(&vis_str, ctx->buf, - VIS_NL | VIS_CSTYLE); - log_debug("header\n%s", vis_str); - free(vis_str); - - if (parse_http_header(ctx) != 0) - goto err; - - p = ctx->buf; - ep += 4; - ctx->bufsz = (ctx->buf + ctx->bufsz) - ep; - ctx->buf = malloc(ctx->bufsz); - memcpy(ctx->buf, ep, ctx->bufsz); - free(p); - } - } - } - - if (events & EV_WRITE) { - if (ctx->state == INIT) { - n = asprintf(&query, - "GET %s HTTP/1.1\r\nHost: %s\r\n" - "Connection: close\r\n\r\n", - captiveportal_conf->captive_portal_path, - captiveportal_conf->captive_portal_host); - write(fd, query, n); - free(query); - event_del(&ctx->ev); - event_set(&ctx->ev, fd, EV_READ | EV_PERSIST, - http_callback, ctx); - event_add(&ctx->ev, &tv); - ctx->state = SENT_QUERY; - } else { - log_warnx("invalid state: %d", ctx->state); - goto err; - } - } - return; -err: - free_http_ctx(ctx); -} - -int -parse_http_header(struct http_ctx *ctx) -{ - char *p, *ep; - const char *errstr; - - /* scan past HTTP/1.x */ - p = strchr(ctx->buf, ' '); - if (p == NULL) - return (1); - while (isspace((int)*p)) - p++; - ep = strchr(p, ' '); - if (ep == NULL) - return (1); - *ep = '\0'; - ctx->status = strtonum(p, 100, 599, &errstr); - if (errstr != NULL) { - log_warnx("%s: status is %s: %s", __func__, errstr, p); - return (1); - } - - log_debug("%s: status: %d", __func__, ctx->status); - - /* ignore parse errors from here on out, we got the status */ - - p = strcasestr(ep + 1, "Content-Length:"); - if (p == NULL) - return (0); - - p += sizeof("Content-Length:") - 1; - while (isspace((int)*p)) - p++; - - ep = strchr(p, '\r'); - if (ep == NULL) - return (0); - - *ep = '\0'; - ctx->content_length = strtonum(p, 0, INT_MAX, &errstr); - if (errstr != NULL) { - log_warnx("%s: Content-Lenght is %s: %s", __func__, errstr, p); - ctx->content_length = -1; - return (0); - } - log_debug("content-length: %d", ctx->content_length); - return (0); -} - -void -check_http_body(struct http_ctx *ctx) -{ - enum captive_portal_state state; - char *p, *vis_str; - - p = recallocarray(ctx->buf, ctx->bufsz, ctx->bufsz + 1, 1); - if (p == NULL) { - log_warn("%s", __func__); - free_http_ctx(ctx); - return; - } - ctx->buf = p; - *(ctx->buf + ctx->bufsz) = '\0'; - ctx->bufsz++; - stravis(&vis_str, ctx->buf, VIS_NL | VIS_CSTYLE); - log_debug("body[%ld]\n%s", ctx->bufsz, vis_str); - - if (ctx->status == captiveportal_conf->captive_portal_expected_status && - strcmp(vis_str, - captiveportal_conf->captive_portal_expected_response) == 0) { - log_debug("%s: not behind captive portal", __func__); - state = NOT_BEHIND; - } else { - log_debug("%s: behind captive portal", __func__); - state = BEHIND; - } - captiveportal_imsg_compose_resolver(IMSG_CAPTIVEPORTAL_STATE, 0, - &state, sizeof(state)); - free_http_ctx(ctx); - http_global_state = IDLE; -} - -void -free_http_ctx(struct http_ctx *ctx) -{ - if (ctx == NULL) - return; - - event_del(&ctx->ev); - close(ctx->fd); - TAILQ_REMOVE(&http_contexts, ctx, entry); - free(ctx->buf); - free(ctx); - http_contexts_count--; -} - -void -close_other_http_contexts(struct http_ctx *octx) -{ - struct http_ctx *ctx, *t; - - log_debug("%s", __func__); - TAILQ_FOREACH_SAFE(ctx, &http_contexts, entry, t) - if(ctx != octx) - free_http_ctx(ctx); -} |