/*

* Copyright (c) 2021, 2022 Omar Polo <op@omarpolo.com>

*

* 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 "gmid.h"

#include <sys/stat.h>

#include <sys/un.h>

#include <assert.h>

#include <ctype.h>

#include <errno.h>

#include <event.h>

#include <fcntl.h>

#include <fnmatch.h>

#include <limits.h>

#include <string.h>

#define MIN(a, b) ((a) < (b) ? (a) : (b))

int shutting_down;

static struct tls *ctx;

static struct event e4, e6, imsgev, siginfo, sigusr2;

static int has_ipv6, has_siginfo;

int connected_clients;

static inline int matches(const char*, const char*);

static int check_path(struct client*, const char*, int*);

static void open_file(struct client*);

static void handle_handshake(int, short, void*);

static const char *strip_path(const char*, int);

static void fmt_sbuf(const char*, struct client*, const char*);

static int apply_block_return(struct client*);

static int check_matching_certificate(X509_STORE *, struct client *);

static int apply_reverse_proxy(struct client *);

static int apply_fastcgi(struct client*);

static int apply_require_ca(struct client*);

static void open_dir(struct client*);

static void redirect_canonical_dir(struct client*);

static void client_tls_readcb(int, short, void *);

static void client_tls_writecb(int, short, void *);

static void client_read(struct bufferevent *, void *);

void client_write(struct bufferevent *, void *);

static void client_error(struct bufferevent *, short, void *);

static void client_close_ev(int, short, void *);

static void do_accept(int, short, void*);

static void handle_dispatch_imsg(int, short, void *);

static void handle_siginfo(int, short, void*);

static uint32_t server_client_id;

struct client_tree_id clients;

static inline int

matches(const char *pattern, const char *path)

{

if (*path == '/')

path++;

return !fnmatch(pattern, path, 0);

}

const char *

vhost_lang(struct vhost *v, const char *path)

{

struct location *loc;

if (v == NULL || path == NULL)

return NULL;

loc = TAILQ_FIRST(&v->locations);

while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {

if (loc->lang != NULL) {

if (matches(loc->match, path))

return loc->lang;

}

}

return TAILQ_FIRST(&v->locations)->lang;

}

const char *

vhost_default_mime(struct vhost *v, const char *path)

{

struct location *loc;

const char *default_mime = "application/octet-stream";

if (v == NULL || path == NULL)

return default_mime;

loc = TAILQ_FIRST(&v->locations);

while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {

if (loc->default_mime != NULL) {

if (matches(loc->match, path))

return loc->default_mime;

}

}

loc = TAILQ_FIRST(&v->locations);

if (loc->default_mime != NULL)

return loc->default_mime;

return default_mime;

}

const char *

vhost_index(struct vhost *v, const char *path)

{

struct location *loc;

const char *index = "index.gmi";

if (v == NULL || path == NULL)

return index;

loc = TAILQ_FIRST(&v->locations);

while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {

if (loc->index != NULL) {

if (matches(loc->match, path))

return loc->index;

}

}

loc = TAILQ_FIRST(&v->locations);

if (loc->index != NULL)

return loc->index;

return index;

}

int

vhost_auto_index(struct vhost *v, const char *path)

{

struct location *loc;

if (v == NULL || path == NULL)

return 0;

loc = TAILQ_FIRST(&v->locations);

while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {

if (loc->auto_index != 0) {

if (matches(loc->match, path))

return loc->auto_index == 1;

}

}

loc = TAILQ_FIRST(&v->locations);

return loc->auto_index == 1;

}

int

vhost_block_return(struct vhost *v, const char *path, int *code, const char **fmt)

{

struct location *loc;

if (v == NULL || path == NULL)

return 0;

loc = TAILQ_FIRST(&v->locations);

while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {

if (loc->block_code != 0) {

if (matches(loc->match, path)) {

*code = loc->block_code;

*fmt = loc->block_fmt;

return 1;

}

}

}

loc = TAILQ_FIRST(&v->locations);

*code = loc->block_code;

*fmt = loc->block_fmt;

return loc->block_code != 0;

}

int

vhost_fastcgi(struct vhost *v, const char *path)

{

struct location *loc;

if (v == NULL || path == NULL)

return -1;

loc = TAILQ_FIRST(&v->locations);

while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {

if (loc->fcgi != -1)

if (matches(loc->match, path))

return loc->fcgi;

}

loc = TAILQ_FIRST(&v->locations);

return loc->fcgi;

}

int

vhost_dirfd(struct vhost *v, const char *path, size_t *retloc)

{

struct location *loc;

size_t l = 0;

if (v == NULL || path == NULL)

return -1;

loc = TAILQ_FIRST(&v->locations);

while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {

l++;

if (loc->dirfd != -1)

if (matches(loc->match, path)) {

*retloc = l;

return loc->dirfd;

}

}

*retloc = 0;

loc = TAILQ_FIRST(&v->locations);

return loc->dirfd;

}

int

vhost_strip(struct vhost *v, const char *path)

{

struct location *loc;

if (v == NULL || path == NULL)

return 0;

loc = TAILQ_FIRST(&v->locations);

while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {

if (loc->strip != 0) {

if (matches(loc->match, path))

return loc->strip;

}

}

loc = TAILQ_FIRST(&v->locations);

return loc->strip;

}

X509_STORE *

vhost_require_ca(struct vhost *v, const char *path)

{

struct location *loc;

if (v == NULL || path == NULL)

return NULL;

loc = TAILQ_FIRST(&v->locations);

while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {

if (loc->reqca != NULL) {

if (matches(loc->match, path))

return loc->reqca;

}

}

loc = TAILQ_FIRST(&v->locations);

return loc->reqca;

}

int

vhost_disable_log(struct vhost *v, const char *path)

{

struct location *loc;

if (v == NULL || path == NULL)

return 0;

loc = TAILQ_FIRST(&v->locations);

while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {

if (loc->disable_log && matches(loc->match, path))

return 1;

}

loc = TAILQ_FIRST(&v->locations);

return loc->disable_log;

}

static int

check_path(struct client *c, const char *path, int *fd)

{

struct stat sb;

const char *p;

int dirfd, strip;

assert(path != NULL);

/*

* in send_dir we add an initial / (to be redirect-friendly),

* but here we want to skip it

*/

if (*path == '/')

path++;

strip = vhost_strip(c->host, path);

p = strip_path(path, strip);

if (*p == '/')

p = p+1;

if (*p == '\0')

p = ".";

dirfd = vhost_dirfd(c->host, path, &c->loc);

log_debug(c, "check_path: strip=%d path=%s original=%s",

strip, p, path);

if (*fd == -1 && (*fd = openat(dirfd, p, O_RDONLY)) == -1) {

if (errno == EACCES)

log_info(c, "can't open %s: %s", p, strerror(errno));

return FILE_MISSING;

}

if (fstat(*fd, &sb) == -1) {

log_notice(c, "failed stat for %s: %s", path, strerror(errno));

return FILE_MISSING;

}

if (S_ISDIR(sb.st_mode))

return FILE_DIRECTORY;

return FILE_EXISTS;

}

static void

open_file(struct client *c)

{

switch (check_path(c, c->iri.path, &c->pfd)) {

case FILE_EXISTS:

c->type = REQUEST_FILE;

start_reply(c, SUCCESS, mime(c->host, c->iri.path));

return;

case FILE_DIRECTORY:

open_dir(c);

return;

case FILE_MISSING:

start_reply(c, NOT_FOUND, "not found");

return;

default:

/* unreachable */

abort();

}

}

void

mark_nonblock(int fd)

{

int flags;

if ((flags = fcntl(fd, F_GETFL)) == -1)

fatal("fcntl(F_GETFL): %s", strerror(errno));

if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)

fatal("fcntl(F_SETFL): %s", strerror(errno));

}

static void

handle_handshake(int fd, short ev, void *d)

{

struct client *c = d;

struct vhost *h;

struct alist *a;

const char *servname;

const char *parse_err = "unknown error";

switch (tls_handshake(c->ctx)) {

case 0: /* success */

case -1: /* already handshaked */

break;

case TLS_WANT_POLLIN:

event_once(c->fd, EV_READ, handle_handshake, c, NULL);

return;

case TLS_WANT_POLLOUT:

event_once(c->fd, EV_WRITE, handle_handshake, c, NULL);

return;

default:

/* unreachable */

abort();

}

c->bev = bufferevent_new(fd, client_read, client_write,

client_error, c);

if (c->bev == NULL)

fatal("%s: failed to allocate client buffer: %s",

__func__, strerror(errno));

event_set(&c->bev->ev_read, c->fd, EV_READ,

client_tls_readcb, c->bev);

event_set(&c->bev->ev_write, c->fd, EV_WRITE,

client_tls_writecb, c->bev);

#if HAVE_LIBEVENT2

evbuffer_unfreeze(c->bev->input, 0);

evbuffer_unfreeze(c->bev->output, 1);

#endif

if ((servname = tls_conn_servername(c->ctx)) == NULL) {

log_debug(c, "handshake: missing SNI");

goto err;

}

if (!puny_decode(servname, c->domain, sizeof(c->domain), &parse_err)) {

log_info(c, "puny_decode: %s", parse_err);

goto err;

}

TAILQ_FOREACH(h, &hosts, vhosts) {

if (matches(h->domain, c->domain))

goto found;

TAILQ_FOREACH(a, &h->aliases, aliases) {

if (matches(a->alias, c->domain))

goto found;

}

}

found:

log_debug(c, "handshake: SNI: \"%s\"; decoded: \"%s\"; matched: \"%s\"",

servname != NULL ? servname : "(null)",

c->domain,

h != NULL ? h->domain : "(null)");

if (h != NULL) {

c->host = h;

bufferevent_enable(c->bev, EV_READ);

return;

}

err:

start_reply(c, BAD_REQUEST, "Wrong/malformed host or missing SNI");

}

static const char *

strip_path(const char *path, int strip)

{

char *t;

while (strip > 0) {

if ((t = strchr(path, '/')) == NULL) {

path = strchr(path, '\0');

break;

}

path = t;

strip--;

}

return path;

}

static void

fmt_sbuf(const char *fmt, struct client *c, const char *path)

{

size_t i;

char buf[32];

memset(buf, 0, sizeof(buf));

for (i = 0; *fmt; ++fmt) {

if (i == sizeof(buf)-1 || *fmt == '%') {

strlcat(c->sbuf, buf, sizeof(c->sbuf));

memset(buf, 0, sizeof(buf));

i = 0;

}

if (*fmt != '%') {

buf[i++] = *fmt;

continue;

}

switch (*++fmt) {

case '%':

strlcat(c->sbuf, "%", sizeof(c->sbuf));

break;

case 'p':

if (*path != '/')

strlcat(c->sbuf, "/", sizeof(c->sbuf));

strlcat(c->sbuf, path, sizeof(c->sbuf));

break;

case 'q':

strlcat(c->sbuf, c->iri.query, sizeof(c->sbuf));

break;

case 'P':

snprintf(buf, sizeof(buf), "%d", conf.port);

strlcat(c->sbuf, buf, sizeof(c->sbuf));

memset(buf, 0, sizeof(buf));

break;

case 'N':

strlcat(c->sbuf, c->domain, sizeof(c->sbuf));

break;

default:

fatal("%s: unknown fmt specifier %c",

__func__, *fmt);

}

}

if (i != 0)

strlcat(c->sbuf, buf, sizeof(c->sbuf));

}

/* 1 if a matching `block return' (and apply it), 0 otherwise */

static int

apply_block_return(struct client *c)

{

const char *fmt, *path;

int code;

if (!vhost_block_return(c->host, c->iri.path, &code, &fmt))

return 0;

path = strip_path(c->iri.path, vhost_strip(c->host, c->iri.path));

fmt_sbuf(fmt, c, path);

start_reply(c, code, c->sbuf);

return 1;

}

static struct proxy *

matched_proxy(struct client *c)

{

struct proxy *p;

const char *proto;

const char *host;

const char *port;

TAILQ_FOREACH(p, &c->host->proxies, proxies) {

if ((proto = p->match_proto) == NULL)

proto = "gemini";

if ((host = p->match_host) == NULL)

host = "*";

if ((port = p->match_port) == NULL)

port = "*";

if (matches(proto, c->iri.schema) &&

matches(host, c->domain) &&

matches(port, c->iri.port))

return p;

}

return NULL;

}

static int

check_matching_certificate(X509_STORE *store, struct client *c)

{

const uint8_t *cert;

size_t len;

if (!tls_peer_cert_provided(c->ctx)) {

start_reply(c, CLIENT_CERT_REQ, "client certificate required");

return 1;

}

cert = tls_peer_cert_chain_pem(c->ctx, &len);

if (!validate_against_ca(store, cert, len)) {

start_reply(c, CERT_NOT_AUTH, "certificate not authorised");

return 1;

}

return 0;

}

static int

proxy_socket(struct client *c, const char *host, const char *port)

{

struct addrinfo hints, *res, *res0;

int r, sock;

memset(&hints, 0, sizeof(hints));

hints.ai_family = AF_UNSPEC;

hints.ai_socktype = SOCK_STREAM;

/* XXX: asr_run? :> */

r = getaddrinfo(host, port, &hints, &res0);

if (r != 0) {

log_warn(c, "getaddrinfo(\"%s\", \"%s\"): %s",

host, port, gai_strerror(r));

return -1;

}

for (res = res0; res; res = res->ai_next) {

sock = socket(res->ai_family, res->ai_socktype,

res->ai_protocol);

if (sock == -1)

continue;

if (connect(sock, res->ai_addr, res->ai_addrlen) == -1) {

close(sock);

sock = -1;

continue;

}

break;

}

freeaddrinfo(res0);

if (sock == -1)

log_warn(c, "can't connect to %s:%s", host, port);

return sock;

}

/* 1 if matching a proxy relay-to (and apply it), 0 otherwise */

static int

apply_reverse_proxy(struct client *c)

{

struct proxy *p;

if ((p = matched_proxy(c)) == NULL)

return 0;

c->proxy = p;

if (p->reqca != NULL && check_matching_certificate(p->reqca, c))

return 1;

log_debug(c, "opening proxy connection for %s:%s",

p->host, p->port);

if ((c->pfd = proxy_socket(c, p->host, p->port)) == -1) {

start_reply(c, PROXY_ERROR, "proxy error");

return 1;

}

mark_nonblock(c->pfd);

if (proxy_init(c) == -1)

start_reply(c, PROXY_ERROR, "proxy error");

return 1;

}

static int

fcgi_open_sock(struct fcgi *f)

{

struct sockaddr_un addr;

int fd;

if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {

log_err(NULL, "socket: %s", strerror(errno));

return -1;

}

memset(&addr, 0, sizeof(addr));

addr.sun_family = AF_UNIX;

strlcpy(addr.sun_path, f->path, sizeof(addr.sun_path));

if (connect(fd, (struct sockaddr*)&addr, sizeof(addr)) == -1) {

log_warn(NULL, "failed to connect to %s: %s", f->path,

strerror(errno));

close(fd);

return -1;

}

return fd;

}

static int

fcgi_open_conn(struct fcgi *f)

{

struct addrinfo hints, *servinfo, *p;

int r, sock;

memset(&hints, 0, sizeof(hints));

hints.ai_family = AF_UNSPEC;

hints.ai_socktype = SOCK_STREAM;

hints.ai_flags = AI_ADDRCONFIG;

if ((r = getaddrinfo(f->path, f->port, &hints, &servinfo)) != 0) {

log_warn(NULL, "getaddrinfo %s:%s: %s", f->path, f->port,

gai_strerror(r));

return -1;

}

for (p = servinfo; p != NULL; p = p->ai_next) {

sock = socket(p->ai_family, p->ai_socktype, p->ai_protocol);

if (sock == -1)

continue;

if (connect(sock, p->ai_addr, p->ai_addrlen) == -1) {

close(sock);

continue;

}

break;

}

if (p == NULL) {

log_warn(NULL, "couldn't connect to %s:%s", f->path, f->port);

sock = -1;

}

freeaddrinfo(servinfo);

return sock;

}

/* 1 if matching `fcgi' (and apply it), 0 otherwise */

static int

apply_fastcgi(struct client *c)

{

int id;

struct fcgi *f;

if ((id = vhost_fastcgi(c->host, c->iri.path)) == -1)

return 0;

f = &fcgi[id];

log_debug(c, "opening fastcgi connection for (%s,%s)",

f->path, f->port);

if (f->port != NULL)

c->pfd = fcgi_open_sock(f);

else

c->pfd = fcgi_open_conn(f);

if (c->pfd == -1) {

start_reply(c, CGI_ERROR, "CGI error");

return 1;

}

mark_nonblock(c->pfd);

c->cgibev = bufferevent_new(c->pfd, fcgi_read, fcgi_write,

fcgi_error, c);

if (c->cgibev == NULL) {

start_reply(c, TEMP_FAILURE, "internal server error");

return 1;

}

bufferevent_enable(c->cgibev, EV_READ|EV_WRITE);

fcgi_req(c);

return 1;

}

/* 1 if matching `require client ca' fails (and apply it), 0 otherwise */

static int

apply_require_ca(struct client *c)

{

X509_STORE *store;

if ((store = vhost_require_ca(c->host, c->iri.path)) == NULL)

return 0;

return check_matching_certificate(store, c);

}

static void

open_dir(struct client *c)

{

size_t len;

int dirfd, root;

char *before_file;

log_debug(c, "in open_dir");

root = !strcmp(c->iri.path, "/") || *c->iri.path == '\0';

len = strlen(c->iri.path);

if (len > 0 && !ends_with(c->iri.path, "/")) {

redirect_canonical_dir(c);

return;

}

strlcpy(c->sbuf, "/", sizeof(c->sbuf));

strlcat(c->sbuf, c->iri.path, sizeof(c->sbuf));

if (!ends_with(c->sbuf, "/"))

strlcat(c->sbuf, "/", sizeof(c->sbuf));

before_file = strchr(c->sbuf, '\0');

len = strlcat(c->sbuf, vhost_index(c->host, c->iri.path),

sizeof(c->sbuf));

if (len >= sizeof(c->sbuf)) {

start_reply(c, TEMP_FAILURE, "internal server error");

return;

}

c->iri.path = c->sbuf;

/* close later unless we have to generate the dir listing */

dirfd = c->pfd;

c->pfd = -1;

switch (check_path(c, c->iri.path, &c->pfd)) {

case FILE_EXISTS:

c->type = REQUEST_FILE;

start_reply(c, SUCCESS, mime(c->host, c->iri.path));

break;

case FILE_DIRECTORY:

start_reply(c, TEMP_REDIRECT, c->sbuf);

break;

case FILE_MISSING:

*before_file = '\0';

if (!vhost_auto_index(c->host, c->iri.path)) {

start_reply(c, NOT_FOUND, "not found");

break;

}

c->type = REQUEST_DIR;

c->dirlen = scandir_fd(dirfd, &c->dir,

root ? select_non_dotdot : select_non_dot,

alphasort);

if (c->dirlen == -1) {

log_err(c, "scandir_fd(%d) (vhost:%s) %s: %s",

c->pfd, c->host->domain, c->iri.path, strerror(errno));

start_reply(c, TEMP_FAILURE, "internal server error");

return;

}

c->diroff = 0;

c->off = 0;

start_reply(c, SUCCESS, "text/gemini");

evbuffer_add_printf(EVBUFFER_OUTPUT(c->bev),

"# Index of %s\n\n", c->iri.path);

return;

default:

/* unreachable */

abort();

}

close(dirfd);

}

static void

redirect_canonical_dir(struct client *c)

{

size_t len;

strlcpy(c->sbuf, "/", sizeof(c->sbuf));

strlcat(c->sbuf, c->iri.path, sizeof(c->sbuf));

len = strlcat(c->sbuf, "/", sizeof(c->sbuf));

if (len >= sizeof(c->sbuf)) {

start_reply(c, TEMP_FAILURE, "internal server error");

return;

}

start_reply(c, TEMP_REDIRECT, c->sbuf);

}

static void

client_tls_readcb(int fd, short event, void *d)

{

struct bufferevent *bufev = d;

struct client *client = bufev->cbarg;

ssize_t ret;

size_t len;

int what = EVBUFFER_READ;

int howmuch = IBUF_READ_SIZE;

char buf[IBUF_READ_SIZE];

if (event == EV_TIMEOUT) {

what |= EVBUFFER_TIMEOUT;

goto err;

}

if (bufev->wm_read.high != 0)

howmuch = MIN(sizeof(buf), bufev->wm_read.high);

switch (ret = tls_read(client->ctx, buf, howmuch)) {

case TLS_WANT_POLLIN:

case TLS_WANT_POLLOUT:

goto retry;

case -1:

what |= EVBUFFER_ERROR;

goto err;

}

len = ret;

if (len == 0) {

what |= EVBUFFER_EOF;

goto err;

}

if (evbuffer_add(bufev->input, buf, len) == -1) {

what |= EVBUFFER_ERROR;

goto err;

}

event_add(&bufev->ev_read, NULL);

if (bufev->wm_read.low != 0 && len < bufev->wm_read.low)

return;

if (bufev->wm_read.high != 0 && len > bufev->wm_read.high) {

/*

* here we could implement a read pressure policy.

*/

}

if (bufev->readcb != NULL)

(*bufev->readcb)(bufev, bufev->cbarg);

return;

retry:

event_add(&bufev->ev_read, NULL);

return;

err:

(*bufev->errorcb)(bufev, what, bufev->cbarg);

}

static void

client_tls_writecb(int fd, short event, void *d)

{

struct bufferevent *bufev = d;

struct client *client = bufev->cbarg;

ssize_t ret;

size_t len;

short what = EVBUFFER_WRITE;

if (event == EV_TIMEOUT) {

what |= EVBUFFER_TIMEOUT;

goto err;

}

if (EVBUFFER_LENGTH(bufev->output) != 0) {

ret = tls_write(client->ctx,

EVBUFFER_DATA(bufev->output),

EVBUFFER_LENGTH(bufev->output));

switch (ret) {

case TLS_WANT_POLLIN:

case TLS_WANT_POLLOUT:

goto retry;

case -1:

what |= EVBUFFER_ERROR;

goto err;

}

len = ret;

evbuffer_drain(bufev->output, len);

}

if (EVBUFFER_LENGTH(bufev->output) != 0)

event_add(&bufev->ev_write, NULL);

if (bufev->writecb != NULL &&

EVBUFFER_LENGTH(bufev->output) <= bufev->wm_write.low)

(*bufev->writecb)(bufev, bufev->cbarg);

return;

retry:

event_add(&bufev->ev_write, NULL);

return;

err:

log_err(client, "tls error: %s", tls_error(client->ctx));

(*bufev->errorcb)(bufev, what, bufev->cbarg);

}

static void

client_read(struct bufferevent *bev, void *d)

{

struct client *c = d;

struct evbuffer *src = EVBUFFER_INPUT(bev);

const char *parse_err = "invalid request";

char decoded[DOMAIN_NAME_LEN];

size_t len;

bufferevent_disable(bev, EVBUFFER_READ);

/*

* libevent2 can still somehow call this function, even

* though I never enable EV_READ in the bufferevent. If

* that's the case, bail out.

*/

if (c->type != REQUEST_UNDECIDED)

return;

/* max url len + \r\n */

if (EVBUFFER_LENGTH(src) > 1024 + 2) {

log_err(c, "too much data received");

start_reply(c, BAD_REQUEST, "bad request");

return;

}

c->req = evbuffer_readln(src, &len, EVBUFFER_EOL_CRLF_STRICT);

if (c->req == NULL) {

/* not enough data yet. */

bufferevent_enable(bev, EVBUFFER_READ);

return;

}

c->reqlen = strlen(c->req);

if (c->reqlen > 1024+2) {

log_err(c, "URL too long");

start_reply(c, BAD_REQUEST, "bad request");

return;

}

if (!parse_iri(c->req, &c->iri, &parse_err) ||

!puny_decode(c->iri.host, decoded, sizeof(decoded), &parse_err)) {

log_err(c, "IRI parse error: %s", parse_err);

start_reply(c, BAD_REQUEST, "bad request");

return;

}

if (apply_reverse_proxy(c))

return;

/* ignore the port number */

if (strcmp(c->iri.schema, "gemini") ||

strcmp(decoded, c->domain)) {

start_reply(c, PROXY_REFUSED, "won't proxy request");

return;

}

if (apply_require_ca(c) ||

apply_block_return(c)||

apply_fastcgi(c))

return;

open_file(c);

}

void

client_write(struct bufferevent *bev, void *d)

{

struct client *c = d;

struct evbuffer *out = EVBUFFER_OUTPUT(bev);

char nam[PATH_MAX];

char buf[BUFSIZ];

ssize_t r;

switch (c->type) {

case REQUEST_UNDECIDED:

/*

* Ignore spurious calls when we still don't have idea

* what to do with the request.

*/

break;

case REQUEST_FILE:

if ((r = read(c->pfd, buf, sizeof(buf))) == -1) {

log_warn(c, "read: %s", strerror(errno));

client_error(bev, EVBUFFER_ERROR, c);

return;

} else if (r == 0) {

client_close(c);

return;

} else if (r != sizeof(buf))

c->type = REQUEST_DONE;

bufferevent_write(bev, buf, r);

break;

case REQUEST_DIR:

/* TODO: handle big big directories better */

for (c->diroff = 0; c->diroff < c->dirlen; ++c->diroff) {

const char *sufx = "";

encode_path(nam, sizeof(nam),

c->dir[c->diroff]->d_name);

if (c->dir[c->diroff]->d_type == DT_DIR)

sufx = "/";

evbuffer_add_printf(out, "=> ./%s%s\n", nam, sufx);

free(c->dir[c->diroff]);

}

free(c->dir);

c->dir = NULL;

c->type = REQUEST_DONE;

event_add(&c->bev->ev_write, NULL);

break;

case REQUEST_FCGI:

case REQUEST_PROXY:

/*

* Here we depend on fastcgi or proxy connection to

* provide data.

*/

break;

case REQUEST_DONE:

if (EVBUFFER_LENGTH(out) == 0)

client_close(c);

break;

}

}

static void

client_error(struct bufferevent *bev, short error, void *d)

{

struct client *c = d;

c->type = REQUEST_DONE;

if (error & EVBUFFER_TIMEOUT) {

log_warn(c, "timeout reached, "

"forcefully closing the connection");

if (c->code == 0)

start_reply(c, BAD_REQUEST, "timeout");

else

client_close(c);

return;

}

if (error & EVBUFFER_EOF) {

client_close(c);

return;

}

log_err(c, "unknown bufferevent error %x", error);

client_close(c);

}

void

start_reply(struct client *c, int code, const char *meta)

{

struct evbuffer *evb = EVBUFFER_OUTPUT(c->bev);

const char *lang;

int r, rr;

bufferevent_enable(c->bev, EVBUFFER_WRITE);

c->code = code;

c->meta = meta;

r = evbuffer_add_printf(evb, "%d %s", code, meta);

if (r == -1)

goto err;

/* 2 digit status + space + 1024 max reply */

if (r > 1027)

goto overflow;

if (c->type != REQUEST_FCGI &&

c->type != REQUEST_PROXY &&

!strcmp(meta, "text/gemini") &&