/***************************************************************************
* nsock_core.c -- This contains the core engine routines for the nsock *
* parallel socket event library. *
* *
***********************IMPORTANT NSOCK LICENSE TERMS***********************
*
* The nsock parallel socket event library is (C) 1999-2023 Nmap Software LLC
* This library is free software; you may redistribute and/or modify it under
* the terms of the GNU General Public License as published by the Free Software
* Foundation; Version 2. This guarantees your right to use, modify, and
* redistribute this software under certain conditions. If this license is
* unacceptable to you, Nmap Software LLC may be willing to sell alternative
* licenses (contact sales@nmap.com ).
*
* As a special exception to the GPL terms, Nmap Software LLC grants permission
* to link the code of this program with any version of the OpenSSL library
* which is distributed under a license identical to that listed in the included
* docs/licenses/OpenSSL.txt file, and distribute linked combinations including
* the two. You must obey the GNU GPL in all respects for all of the code used
* other than OpenSSL. If you modify this file, you may extend this exception to
* your version of the file, but you are not obligated to do so.
*
* If you received these files with a written license agreement stating terms
* other than the (GPL) terms above, then that alternative license agreement
* takes precedence over this comment.
*
* Source is provided to this software because we believe users have a right to
* know exactly what a program is going to do before they run it. This also
* allows you to audit the software for security holes.
*
* Source code also allows you to port Nmap to new platforms, fix bugs, and add
* new features. You are highly encouraged to send your changes to the
* dev@nmap.org mailing list for possible incorporation into the main
* distribution. By sending these changes to Fyodor or one of the Insecure.Org
* development mailing lists, or checking them into the Nmap source code
* repository, it is understood (unless you specify otherwise) that you are
* offering the Nmap Project (Nmap Software LLC) the unlimited, non-exclusive
* right to reuse, modify, and relicense the code. Nmap will always be available
* Open Source, but this is important because the inability to relicense code
* has caused devastating problems for other Free Software projects (such as KDE
* and NASM). We also occasionally relicense the code to third parties as
* discussed above. If you wish to specify special license conditions of your
* contributions, just say so when you send them.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License v2.0 for more
* details (http://www.gnu.org/licenses/gpl-2.0.html).
*
***************************************************************************/
/* $Id$ */
#include "nsock_internal.h"
#include "gh_list.h"
#include "filespace.h"
#include "nsock_log.h"
#include <assert.h>
#if HAVE_ERRNO_H
#include <errno.h>
#endif
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#if HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#if HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#if HAVE_STRING_H
#include <string.h>
#endif
#include "netutils.h"
#if HAVE_PCAP
#include "nsock_pcap.h"
#endif
/* Nsock time of day -- we update this at least once per nsock_loop round (and
* after most calls that are likely to block). Other nsock files should grab
* this */
struct timeval nsock_tod;
/* Internal function defined in nsock_event.c
* Update the nse->iod first events, assuming nse is about to be deleted */
void update_first_events(struct nevent *nse);
/* Each iod has a count of pending socket reads, socket writes, and pcap reads.
* When a descriptor's count is nonzero, its bit must be set in the appropriate
* master fd_set, and when the count is zero the bit must be cleared. What we
* are simulating is an fd_set with a counter for each socket instead of just an
* on/off switch. The fd_set's bits aren't enough by itself because a descriptor
* may for example have two reads pending at once, and the bit must not be
* cleared after the first is completed.
* The socket_count_* functions return the event to transmit to update_events()
*/
int socket_count_zero(struct niod *iod, struct npool *ms) {
iod->readsd_count = 0;
iod->writesd_count = 0;
#if HAVE_PCAP
iod->readpcapsd_count = 0;
#endif
return nsock_engine_iod_unregister(ms, iod);
}
static int socket_count_read_inc(struct niod *iod) {
assert(iod->readsd_count >= 0);
iod->readsd_count++;
return EV_READ;
}
static int socket_count_read_dec(struct niod *iod) {
assert(iod->readsd_count > 0);
iod->readsd_count--;
return (iod->readsd_count == 0) ? EV_READ : EV_NONE;
}
static int socket_count_write_inc(struct niod *iod) {
assert(iod->writesd_count >= 0);
iod->writesd_count++;
return EV_WRITE;
}
static int socket_count_write_dec(struct niod *iod) {
assert(iod->writesd_count > 0);
iod->writesd_count--;
return (iod->writesd_count == 0) ? EV_WRITE : EV_NONE;
}
#if HAVE_PCAP
static int socket_count_readpcap_inc(struct niod *iod) {
assert(iod->readpcapsd_count >= 0);
iod->readpcapsd_count++;
return EV_READ;
}
static int socket_count_readpcap_dec(struct niod *iod) {
assert(iod->readpcapsd_count > 0);
iod->readpcapsd_count--;
return (iod->readpcapsd_count == 0) ? EV_READ : EV_NONE;
}
#endif
#if HAVE_OPENSSL
/* Call socket_count_read_dec or socket_count_write_dec on nse->iod depending on
* the current value of nse->sslinfo.ssl_desire. */
static int socket_count_dec_ssl_desire(struct nevent *nse) {
assert(nse->iod->ssl != NULL);
assert(nse->sslinfo.ssl_desire == SSL_ERROR_WANT_READ ||
nse->sslinfo.ssl_desire == SSL_ERROR_WANT_WRITE);
if (nse->sslinfo.ssl_desire == SSL_ERROR_WANT_READ)
return socket_count_read_dec(nse->iod);
else
return socket_count_write_dec(nse->iod);
}
#endif
static int should_clear_ev_read(const struct niod *iod, int ev_set) {
return (ev_set & EV_READ) &&
#if HAVE_PCAP
!iod->readpcapsd_count &&
#endif
!iod->readsd_count;
}
static int should_clear_ev_write(const struct niod *iod, int ev_set) {
return (ev_set & EV_WRITE) && !iod->writesd_count;
}
/* Update the events that the IO engine should watch for a given IOD.
*
* ev_inc is a set of events for which the event counters should be increased.
* These events will therefore be watched by the IO engine for this IOD.
*
* ev_dec is a set of events for which the event counters should be decreased.
* If this counter reaches zero, the event won't be watched anymore by the
* IO engine for this IOD.
*/
static void update_events(struct niod * iod, struct npool *ms, struct nevent *nse, int ev_inc, int ev_dec) {
int setmask, clrmask, ev_temp;
/* Filter out events that belong to both sets. */
ev_temp = ev_inc ^ ev_dec;
ev_inc = ev_inc & ev_temp;
ev_dec = ev_dec & ev_temp;
setmask = ev_inc;
clrmask = EV_NONE;
if (should_clear_ev_read(iod, ev_dec))
clrmask |= EV_READ;
if (should_clear_ev_write(iod, ev_dec))
clrmask |= EV_WRITE;
/* EV_EXCEPT is systematically set and cannot be removed */
if (ev_inc & EV_EXCEPT)
nsock_log_info("Invalid event set, no need to specify EV_EXCEPT");
if (ev_dec & EV_EXCEPT)
nsock_log_info("Invalid event set, refusing to clear EV_EXCEPT");
if (!IOD_PROPGET(iod, IOD_REGISTERED)) {
assert(clrmask == EV_NONE);
nsock_engine_iod_register(ms, iod, nse, setmask);
} else {
nsock_engine_iod_modify(ms, iod, nse, setmask, clrmask);
}
}
/* Add a new event for a given IOD. nevents are stored in separate event lists
* (in the nsock pool) and are grouped by IOD within each list.
*
* This function appends the event _before_ the first similar event we have for
* the given IOD, or append it to the end of the list if no similar event is
* already present.
*
* Note that adding the event before the similar ones is important for
* reentrancy, as it will prevent the new event to be processed in the event
* loop just after its addition.
*/
static int iod_add_event(struct niod *iod, struct nevent *nse) {
struct npool *nsp = iod->nsp;
switch (nse->type) {
case NSE_TYPE_CONNECT:
case NSE_TYPE_CONNECT_SSL:
if (iod->first_connect)
gh_list_insert_before(&nsp->connect_events,
iod->first_connect, &nse->nodeq_io);
else
gh_list_append(&nsp->connect_events, &nse->nodeq_io);
iod->first_connect = &nse->nodeq_io;
break;
case NSE_TYPE_READ:
if (iod->first_read)
gh_list_insert_before(&nsp->read_events, iod->first_read, &nse->nodeq_io);
else
gh_list_append(&nsp->read_events, &nse->nodeq_io);
iod->first_read = &nse->nodeq_io;
break;
case NSE_TYPE_WRITE:
if (iod->first_write)
gh_list_insert_before(&nsp->write_events, iod->first_write, &nse->nodeq_io);
else
gh_list_append(&nsp->write_events, &nse->nodeq_io);
iod->first_write = &nse->nodeq_io;
break;
#if HAVE_PCAP
case NSE_TYPE_PCAP_READ: {
char add_read = 0, add_pcap_read = 0;
#if PCAP_BSD_SELECT_HACK
/* BSD hack mode: add event to both read and pcap_read lists */
add_read = add_pcap_read = 1;
#else
if (((mspcap *)iod->pcap)->pcap_desc >= 0) {
add_read = 1;
} else {
add_pcap_read = 1;
}
#endif
if (add_read) {
if (iod->first_read)
gh_list_insert_before(&nsp->read_events, iod->first_read, &nse->nodeq_io);
else
gh_list_append(&nsp->read_events, &nse->nodeq_io);
iod->first_read = &nse->nodeq_io;
}
if (add_pcap_read) {
if (iod->first_pcap_read)
gh_list_insert_before(&nsp->pcap_read_events, iod->first_pcap_read,
&nse->nodeq_pcap);
else
gh_list_append(&nsp->pcap_read_events, &nse->nodeq_pcap);
iod->first_pcap_read = &nse->nodeq_pcap;
}
break;
}
#endif
default:
fatal("Unknown event type (%d) for IOD #%lu\n", nse->type, iod->id);
}
return 0;
}
/* A handler function is defined for each of the main event types (read, write,
* connect, timer, etc) -- the handler is called when new information is
* available for the event. The handler makes any necessary updates to the
* event based on any new information available. If the event becomes ready for
* delivery, the handler sets nse->event_done and fills out the relevant event
* fields (status, errnum) as applicable. The handlers also take care of event
* type specific teardown (such as clearing socket descriptors from select/poll
* lists). If event_done is not set, the handler will be called again in the
* case of more information or an event timeout */
/* The event type handlers -- the first three arguments of each are the same:
* struct npool *ms struct nevent *nse -- the event we have new info on enum nse_status --
* The reason for the call, usually NSE_STATUS_SUCCESS (which generally means a
* successful I/O call or NSE_STATUS_TIMEOUT or NSE_STATUS_CANCELLED
*
* Some of the event type handlers have other parameters, specific to their
* needs. All the handlers can assume that the calling function has checked
* that select or poll said their descriptors were readable/writeable (as
* appropriate).
*
* The idea is that each handler will take care of the stuff that is specific
* to it and the calling function will handle the stuff that can be generalized
* to dispatching/deleting/etc. all events. But the calling function may use
* type-specific info to determine whether the handler should be called at all
* (to save CPU time). */
/* handle_connect_results assumes that select or poll have already shown the
* descriptor to be active */
void handle_connect_result(struct npool *ms, struct nevent *nse, enum nse_status status) {
int optval;
socklen_t optlen = sizeof(int);
struct niod *iod = nse->iod;
assert(iod != NULL);
#if HAVE_OPENSSL
int sslerr;
int rc = 0;
int sslconnect_inprogress = nse->type == NSE_TYPE_CONNECT_SSL && nse->iod &&
(nse->sslinfo.ssl_desire == SSL_ERROR_WANT_READ ||
nse->sslinfo.ssl_desire == SSL_ERROR_WANT_WRITE);
SSL_CTX *sslctx = NULL;
#else
int sslconnect_inprogress = 0;
#endif
if (status == NSE_STATUS_TIMEOUT || status == NSE_STATUS_CANCELLED) {
nse->status = status;
nse->event_done = 1;
} else if (sslconnect_inprogress) {
/* Do nothing */
} else if (status == NSE_STATUS_SUCCESS) {
/* First we want to determine whether the socket really is connected */
if (getsockopt(iod->sd, SOL_SOCKET, SO_ERROR, (char *)&optval, &optlen) != 0)
optval = socket_errno(); /* Stupid Solaris */
if (optval == 0) {
nse->status = NSE_STATUS_SUCCESS;
}
else {
nse->status = NSE_STATUS_ERROR;
nse->errnum = optval;
}
/* Now special code for the SSL case where the TCP connection was successful. */
if (nse->type == NSE_TYPE_CONNECT_SSL &&
nse->status == NSE_STATUS_SUCCESS) {
#if HAVE_OPENSSL
sslctx = iod->lastproto == IPPROTO_UDP ? ms->dtlsctx : ms->sslctx;
assert(sslctx != NULL);
/* Reuse iod->ssl if present. If set, this is the second try at connection
without the SSL_OP_NO_SSLv2 option set. */
if (iod->ssl == NULL) {
iod->ssl = SSL_new(sslctx);
if (!iod->ssl)
fatal("SSL_new failed: %s", ERR_error_string(ERR_get_error(), NULL));
}
#if HAVE_SSL_SET_TLSEXT_HOST_NAME
/* Avoid sending SNI extension with DTLS because many servers don't allow
* fragmented ClientHello messages. */
if (iod->hostname != NULL && iod->lastproto != IPPROTO_UDP) {
if (SSL_set_tlsext_host_name(iod->ssl, iod->hostname) != 1)
fatal("SSL_set_tlsext_host_name failed: %s", ERR_error_string(ERR_get_error(), NULL));
}
#endif
/* Associate our new SSL with the connected socket. It will inherit the
* non-blocking nature of the sd */
if (SSL_set_fd(iod->ssl, iod->sd) != 1)
fatal("SSL_set_fd failed: %s", ERR_error_string(ERR_get_error(), NULL));
/* Event not done -- need to do SSL connect below */
nse->sslinfo.ssl_desire = SSL_ERROR_WANT_CONNECT;
#endif
} else {
/* This is not an SSL connect (in which case we are always done), or the
* TCP connect() underlying the SSL failed (in which case we are also done */
nse->event_done = 1;
}
} else {
fatal("Unknown status (%d)", status);
}
/* At this point the TCP connection is done, whether successful or not.
* Therefore decrease the read/write listen counts that were incremented in
* nsock_pool_add_event. In the SSL case, we may increase one of the counts depending
* on whether SSL_connect returns an error of SSL_ERROR_WANT_READ or
* SSL_ERROR_WANT_WRITE. In that case we will re-enter this function, but we
* don't want to execute this block again. */
if (iod->sd != -1 && !sslconnect_inprogress) {
int ev = EV_NONE;
ev |= socket_count_read_dec(iod);
ev |= socket_count_write_dec(iod);
update_events(iod, ms, nse, EV_NONE, ev);
}
#if HAVE_OPENSSL
if (nse->type == NSE_TYPE_CONNECT_SSL && !nse->event_done) {
/* Lets now start/continue/finish the connect! */
if (iod->ssl_session) {
rc = SSL_set_session(iod->ssl, iod->ssl_session);
if (rc == 0)
nsock_log_error("Uh-oh: SSL_set_session() failed - please tell dev@nmap.org");
iod->ssl_session = NULL; /* No need for this any more */
}
/* If this is a reinvocation of handle_connect_result, clear out the listen
* bits that caused it, based on the previous SSL desire. */
if (sslconnect_inprogress) {
int ev;
ev = socket_count_dec_ssl_desire(nse);
update_events(iod, ms, nse, EV_NONE, ev);
}
rc = SSL_connect(iod->ssl);
if (rc == 1) {
/* Woop! Connect is done! */
nse->event_done = 1;
/* Check that certificate verification was okay, if requested. */
if (nsi_ssl_post_connect_verify(iod)) {
nse->status = NSE_STATUS_SUCCESS;
} else {
nsock_log_error("certificate verification error for EID %li: %s",
nse->id, ERR_error_string(ERR_get_error(), NULL));
nse->status = NSE_STATUS_ERROR;
}
} else {
#if SSL_OP_NO_SSLv2 != 0
long options = SSL_get_options(iod->ssl);
#endif
sslerr = SSL_get_error(iod->ssl, rc);
if (sslerr == SSL_ERROR_WANT_READ) {
nse->sslinfo.ssl_desire = sslerr;
socket_count_read_inc(iod);
update_events(iod, ms, nse, EV_READ, EV_NONE);
} else if (sslerr == SSL_ERROR_WANT_WRITE) {
nse->sslinfo.ssl_desire = sslerr;
socket_count_write_inc(iod);
update_events(iod, ms, nse, EV_WRITE, EV_NONE);
#if SSL_OP_NO_SSLv2 != 0
} else if (iod->lastproto != IPPROTO_UDP && !(options & SSL_OP_NO_SSLv2)) {
/* SSLv2 does not apply to DTLS, so ensure lastproto was not UDP. */
int saved_ev;
/* SSLv3-only and TLSv1-only servers can't be connected to when the
* SSL_OP_NO_SSLv2 option is not set, which is the case when the pool
* was initialized with nsock_pool_ssl_init_max_speed. Try reconnecting
* with SSL_OP_NO_SSLv2. Never downgrade a NO_SSLv2 connection to one
* that might use SSLv2. */
nsock_log_info("EID %li reconnecting with SSL_OP_NO_SSLv2", nse->id);
saved_ev = iod->watched_events;
nsock_engine_iod_unregister(ms, iod);
close(iod->sd);
nsock_connect_internal(ms, nse, SOCK_STREAM, iod->lastproto, &iod->peer,
iod->peerlen, nsock_iod_get_peerport(iod));
nsock_engine_iod_register(ms, iod, nse, saved_ev);
/* Use SSL_free here because SSL_clear keeps session info, which
* doesn't work when changing SSL versions (as we're clearly trying to
* do by adding SSL_OP_NO_SSLv2). */
SSL_free(iod->ssl);
iod->ssl = SSL_new(ms->sslctx);
if (!iod->ssl)
fatal("SSL_new failed: %s", ERR_error_string(ERR_get_error(), NULL));
SSL_set_options(iod->ssl, options | SSL_OP_NO_SSLv2);
socket_count_read_inc(nse->iod);
socket_count_write_inc(nse->iod);
update_events(iod, ms, nse, EV_READ|EV_WRITE, EV_NONE);
nse->sslinfo.ssl_desire = SSL_ERROR_WANT_CONNECT;
#endif
} else {
nsock_log_info("EID %li %s",
nse->id, ERR_error_string(ERR_get_error(), NULL));
nse->event_done = 1;
nse->status = NSE_STATUS_ERROR;
nse->errnum = EIO;
}
}
}
#endif
}
static int errcode_is_failure(int err) {
#ifndef WIN32
return err != EINTR && err != EAGAIN && err != EBUSY;
#else
return err != EINTR && err != EAGAIN;
#endif
}
void handle_write_result(struct npool *ms, struct nevent *nse, enum nse_status status) {
int bytesleft;
char *str;
int res;
int err;
struct niod *iod = nse->iod;
if (status == NSE_STATUS_TIMEOUT || status == NSE_STATUS_CANCELLED) {
nse->event_done = 1;
nse->status = status;
} else if (status == NSE_STATUS_SUCCESS) {
str = fs_str(&nse->iobuf) + nse->writeinfo.written_so_far;
bytesleft = fs_length(&nse->iobuf) - nse->writeinfo.written_so_far;
if (nse->writeinfo.written_so_far > 0)
assert(bytesleft > 0);
#if HAVE_OPENSSL
if (iod->ssl)
res = SSL_write(iod->ssl, str, bytesleft);
else
#endif
res = ms->engine->io_operations->iod_write(ms, nse->iod->sd, str, bytesleft, 0, (struct sockaddr *)&nse->writeinfo.dest, (int)nse->writeinfo.destlen);
if (res == bytesleft) {
nse->event_done = 1;
nse->status = NSE_STATUS_SUCCESS;
} else if (res >= 0) {
nse->writeinfo.written_so_far += res;
} else {
assert(res == -1);
if (iod->ssl) {
#if HAVE_OPENSSL
err = SSL_get_error(iod->ssl, res);
if (err == SSL_ERROR_WANT_READ) {
int evclr;
evclr = socket_count_dec_ssl_desire(nse);
socket_count_read_inc(iod);
update_events(iod, ms, nse, EV_READ, evclr);
nse->sslinfo.ssl_desire = err;
} else if (err == SSL_ERROR_WANT_WRITE) {
int evclr;
evclr = socket_count_dec_ssl_desire(nse);
socket_count_write_inc(iod);
update_events(iod, ms, nse, EV_WRITE, evclr);
nse->sslinfo.ssl_desire = err;
} else {
/* Unexpected error */
nse->event_done = 1;
nse->status = NSE_STATUS_ERROR;
nse->errnum = EIO;
}
#endif
} else {
err = socket_errno();
if (errcode_is_failure(err)) {
nse->event_done = 1;
nse->status = NSE_STATUS_ERROR;
nse->errnum = err;
}
}
}
if (res >= 0)
nse->iod->write_count += res;
}
if (nse->event_done && nse->iod->sd != -1) {
int ev = EV_NONE;
#if HAVE_OPENSSL
if (nse->iod->ssl != NULL)
ev |= socket_count_dec_ssl_desire(nse);
else
#endif
ev |= socket_count_write_dec(nse->iod);
update_events(nse->iod, ms, nse, EV_NONE, ev);
}
}
void handle_timer_result(struct npool *ms, struct nevent *nse, enum nse_status status) {
/* Ooh this is a hard job :) */
nse->event_done = 1;
nse->status = status;
}
/* Returns -1 if an error, otherwise the number of newly written bytes */
static int do_actual_read(struct npool *ms, struct nevent *nse) {
char buf[READ_BUFFER_SZ];
int buflen = 0;
struct niod *iod = nse->iod;
int err = 0;
int max_chunk = NSOCK_READ_CHUNK_SIZE;
int startlen = fs_length(&nse->iobuf);
int enotsock = 0; /* Did we get ENOTSOCK once? */
if (nse->readinfo.read_type == NSOCK_READBYTES)
max_chunk = nse->readinfo.num;
if (!iod->ssl) {
do {
struct sockaddr_storage peer;
socklen_t peerlen;
peerlen = sizeof(peer);
if (enotsock) {
peer.ss_family = AF_UNSPEC;
peerlen = 0;
buflen = read(iod->sd, buf, sizeof(buf));
}
else {
buflen = ms->engine->io_operations->iod_read(ms, iod->sd, buf, sizeof(buf), 0, (struct sockaddr *)&peer, &peerlen);
/* Using recv() was failing, at least on UNIX, for non-network sockets
* (i.e. stdin) in this case, a read() is done - as on ENOTSOCK we may
* have a non-network socket */
if (buflen == -1) {
if (socket_errno() == ENOTSOCK) {
enotsock = 1;
peer.ss_family = AF_UNSPEC;
peerlen = 0;
buflen = read(iod->sd, buf, sizeof(buf));
}
}
}
if (buflen == -1) {
err = socket_errno();
}
else {
/* Windows will ignore src_addr and addrlen arguments to recvfrom on TCP
* sockets, so peerlen is still sizeof(peer) and peer is junk. Instead,
* only set this if it's not already set.
*/
if (peerlen > 0 && iod->peerlen == 0) {
assert(peerlen <= sizeof(iod->peer));
memcpy(&iod->peer, &peer, peerlen);
iod->peerlen = peerlen;
}
if (buflen > 0) {
if (fs_cat(&nse->iobuf, buf, buflen) == -1) {
nse->event_done = 1;
nse->status = NSE_STATUS_ERROR;
nse->errnum = ENOMEM;
return -1;
}
/* Sometimes a service just spews and spews data. So we return after a
* somewhat large amount to avoid monopolizing resources and avoid DOS
* attacks. */
if (fs_length(&nse->iobuf) > max_chunk)
return fs_length(&nse->iobuf) - startlen;
/* No good reason to read again if we we were successful in the read but
* didn't fill up the buffer. Especially for UDP, where we want to
* return only one datagram at a time. The consistency of the above
* assignment of iod->peer depends on not consolidating more than one
* UDP read buffer. */
if (buflen < sizeof(buf))
return fs_length(&nse->iobuf) - startlen;
}
}
} while (buflen > 0 || (buflen == -1 && err == EINTR));
if (buflen == -1) {
if (err != EINTR && err != EAGAIN) {
nse->event_done = 1;
nse->status = NSE_STATUS_ERROR;
nse->errnum = err;
return -1;
}
}
} else {
#if HAVE_OPENSSL
/* OpenSSL read */
while ((buflen = SSL_read(iod->ssl, buf, sizeof(buf))) > 0) {
if (fs_cat(&nse->iobuf, buf, buflen) == -1) {
nse->event_done = 1;
nse->status = NSE_STATUS_ERROR;
nse->errnum = ENOMEM;
return -1;
}
/* Sometimes a service just spews and spews data. So we return
* after a somewhat large amount to avoid monopolizing resources
* and avoid DOS attacks. */
if (fs_length(&nse->iobuf) > max_chunk)
return fs_length(&nse->iobuf) - startlen;
}
if (buflen == -1) {
err = SSL_get_error(iod->ssl, buflen);
if (err == SSL_ERROR_WANT_READ) {
int evclr;
evclr = socket_count_dec_ssl_desire(nse);
socket_count_read_inc(iod);
update_events(iod, ms, nse, EV_READ, evclr);
nse->sslinfo.ssl_desire = err;
} else if (err == SSL_ERROR_WANT_WRITE) {
int evclr;
evclr = socket_count_dec_ssl_desire(nse);
socket_count_write_inc(iod);
update_events(iod, ms, nse, EV_WRITE, evclr);
nse->sslinfo.ssl_desire = err;
} else {
/* Unexpected error */
nse->event_done = 1;
nse->status = NSE_STATUS_ERROR;
nse->errnum = EIO;
nsock_log_info("SSL_read() failed for reason %s on NSI %li",
ERR_error_string(err, NULL), iod->id);
return -1;
}
}
#endif /* HAVE_OPENSSL */
}
if (buflen == 0) {
nse->event_done = 1;
nse->eof = 1;
if (fs_length(&nse->iobuf) > 0) {
nse->status = NSE_STATUS_SUCCESS;
return fs_length(&nse->iobuf) - startlen;
} else {
nse->status = NSE_STATUS_EOF;
return 0;
}
}
return fs_length(&nse->iobuf) - startlen;
}
void handle_read_result(struct npool *ms, struct nevent *nse, enum nse_status status) {
unsigned int count;
char *str;
int rc, len;
struct niod *iod = nse->iod;
if (status == NSE_STATUS_TIMEOUT) {
nse->event_done = 1;
if (fs_length(&nse->iobuf) > 0)
nse->status = NSE_STATUS_SUCCESS;
else
nse->status = NSE_STATUS_TIMEOUT;
} else if (status == NSE_STATUS_CANCELLED) {
nse->status = status;
nse->event_done = 1;
} else if (status == NSE_STATUS_SUCCESS) {
rc = do_actual_read(ms, nse);
/* printf("DBG: Just read %d new bytes%s.\n", rc, iod->ssl? "( SSL!)" : ""); */
if (rc > 0) {
nse->iod->read_count += rc;
/* We decide whether we have read enough to return */
switch (nse->readinfo.read_type) {
case NSOCK_READ:
nse->status = NSE_STATUS_SUCCESS;
nse->event_done = 1;
break;
case NSOCK_READBYTES:
if (fs_length(&nse->iobuf) >= nse->readinfo.num) {
nse->status = NSE_STATUS_SUCCESS;
nse->event_done = 1;
}
/* else we are not done */
break;
case NSOCK_READLINES:
/* Lets count the number of lines we have ... */
count = 0;
len = fs_length(&nse->iobuf) -1;
str = fs_str(&nse->iobuf);
for (count=0; len >= 0; len--) {
if (str[len] == '\n') {
count++;
if ((int)count >= nse->readinfo.num)
break;
}
}
if ((int) count >= nse->readinfo.num) {
nse->event_done = 1;
nse->status = NSE_STATUS_SUCCESS;
}
/* Else we are not done */
break;
default:
fatal("Unknown operation type (%d)", (int)nse->readinfo.read_type);
}
}
} else {
fatal("Unknown status (%d)", status);
}
/* If there are no more reads for this IOD, we are done reading on the socket
* so we can take it off the descriptor list ... */
if (nse->event_done && iod->sd >= 0) {
int ev = EV_NONE;
#if HAVE_OPENSSL
if (nse->iod->ssl != NULL)
ev |= socket_count_dec_ssl_desire(nse);
else
#endif
ev |= socket_count_read_dec(nse->iod);
update_events(nse->iod, ms, nse, EV_NONE, ev);
}
}
#if HAVE_PCAP
void handle_pcap_read_result(struct npool *ms, struct nevent *nse, enum nse_status status) {
struct niod *iod = nse->iod;
mspcap *mp = (mspcap *)iod->pcap;
switch (status) {
case NSE_STATUS_TIMEOUT:
nse->status = NSE_STATUS_TIMEOUT;
nse->event_done = 1;
break;
case NSE_STATUS_CANCELLED:
nse->status = NSE_STATUS_CANCELLED;
nse->event_done = 1;
break;
case NSE_STATUS_SUCCESS:
/* check if we already have something read */
if (fs_length(&(nse->iobuf)) == 0) {
nse->status = NSE_STATUS_TIMEOUT;
nse->event_done = 0;
} else {
nse->status = NSE_STATUS_SUCCESS; /* we have full buffer */
nse->event_done = 1;
}
break;
default:
fatal("Unknown status (%d) for nsock event #%lu", status, nse->id);
}
/* If there are no more read events, we are done reading on the socket so we
* can take it off the descriptor list... */
if (nse->event_done && mp->pcap_desc >= 0) {
int ev;
ev = socket_count_readpcap_dec(iod);
update_events(iod, ms, nse, EV_NONE, ev);
}
}
/* Returns whether something was read */
int pcap_read_on_nonselect(struct npool *nsp) {
gh_lnode_t *current, *next;
struct nevent *nse;
int ret = 0;
for (current = gh_list_first_elem(&nsp->pcap_read_events);
current != NULL;
current = next) {
nse = lnode_nevent2(current);
if (do_actual_pcap_read(nse) == 1) {
/* something received */
ret++;
break;
}
next = gh_lnode_next(current);
}
return ret;
}
#endif /* HAVE_PCAP */
/* Here is the all important looping function that tells the event engine to
* start up and begin processing events. It will continue until all events have
* been delivered (including new ones started from event handlers), or the
* msec_timeout is reached, or a major error has occurred. Use -1 if you don't
* want to set a maximum time for it to run. A timeout of 0 will return after 1
* non-blocking loop. The nsock loop can be restarted again after it returns.
* For example you could do a series of 15 second runs, allowing you to do other
* stuff between them */
enum nsock_loopstatus nsock_loop(nsock_pool nsp, int msec_timeout) {
struct npool *ms = (struct npool *)nsp;
struct timeval loop_timeout;
int msecs_left;
unsigned long loopnum = 0;
enum nsock_loopstatus quitstatus = NSOCK_LOOP_ERROR;
gettimeofday(&nsock_tod, NULL);
if (msec_timeout < -1) {
ms->errnum = EINVAL;
return NSOCK_LOOP_ERROR;
}
TIMEVAL_MSEC_ADD(loop_timeout, nsock_tod, msec_timeout);
msecs_left = msec_timeout;
if (msec_timeout >= 0)
nsock_log_debug("nsock_loop() started (timeout=%dms). %d events pending",
msec_timeout, ms->events_pending);
else
nsock_log_debug("nsock_loop() started (no timeout). %d events pending",
ms->events_pending);
while (1) {
if (ms->quit) {
/* We've been asked to quit the loop through nsock_loop_quit. */
ms->quit = 0;
quitstatus = NSOCK_LOOP_QUIT;
break;
}
if (ms->events_pending == 0) {
/* if no events at all are pending, then none can be created until
* we quit nsock_loop() -- so we do that now. */
quitstatus = NSOCK_LOOP_NOEVENTS;
break;
}
if (msec_timeout >= 0) {
msecs_left = MAX(0, TIMEVAL_MSEC_SUBTRACT(loop_timeout, nsock_tod));
if (msecs_left == 0 && loopnum > 0) {
quitstatus = NSOCK_LOOP_TIMEOUT;
break;
}
}
if (nsock_engine_loop(ms, msecs_left) == -1) {
quitstatus = NSOCK_LOOP_ERROR;
break;
}
gettimeofday(&nsock_tod, NULL); /* we do this at end because there is one
* at beginning of function */
loopnum++;
}
return quitstatus;
}
void process_event(struct npool *nsp, gh_list_t *evlist, struct nevent *nse, int ev) {
int match_r = ev & EV_READ;
int match_w = ev & EV_WRITE;
int match_x = ev & EV_EXCEPT;
#if HAVE_OPENSSL
int desire_r = 0, desire_w = 0;
#endif
nsock_log_debug_all("Processing event %lu (timeout in %ldms, done=%d)",
nse->id,
(long)TIMEVAL_MSEC_SUBTRACT(nse->timeout, nsock_tod),
nse->event_done);
if (!nse->event_done) {
switch (nse->type) {
case NSE_TYPE_CONNECT:
case NSE_TYPE_CONNECT_SSL:
if (ev != EV_NONE)
handle_connect_result(nsp, nse, NSE_STATUS_SUCCESS);
if (event_timedout(nse))
handle_connect_result(nsp, nse, NSE_STATUS_TIMEOUT);
break;
case NSE_TYPE_READ:
#if HAVE_OPENSSL
desire_r = nse->sslinfo.ssl_desire == SSL_ERROR_WANT_READ;
desire_w = nse->sslinfo.ssl_desire == SSL_ERROR_WANT_WRITE;
if (nse->iod->ssl && ((desire_r && match_r) || (desire_w && match_w)))
handle_read_result(nsp, nse, NSE_STATUS_SUCCESS);
else
#endif
if ((!nse->iod->ssl && match_r) || match_x)
handle_read_result(nsp, nse, NSE_STATUS_SUCCESS);
if (event_timedout(nse))
handle_read_result(nsp, nse, NSE_STATUS_TIMEOUT);
break;
case NSE_TYPE_WRITE:
#if HAVE_OPENSSL
desire_r = nse->sslinfo.ssl_desire == SSL_ERROR_WANT_READ;
desire_w = nse->sslinfo.ssl_desire == SSL_ERROR_WANT_WRITE;
if (nse->iod->ssl && ((desire_r && match_r) || (desire_w && match_w)))
handle_write_result(nsp, nse, NSE_STATUS_SUCCESS);
else
#endif
if ((!nse->iod->ssl && match_w) || match_x)
handle_write_result(nsp, nse, NSE_STATUS_SUCCESS);
if (event_timedout(nse))
handle_write_result(nsp, nse, NSE_STATUS_TIMEOUT);
break;
case NSE_TYPE_TIMER:
if (event_timedout(nse))
handle_timer_result(nsp, nse, NSE_STATUS_SUCCESS);
break;
#if HAVE_PCAP
case NSE_TYPE_PCAP_READ:{
nsock_log_debug_all("PCAP iterating %lu", nse->id);
if (ev & EV_READ) {
/* buffer empty? check it! */
if (fs_length(&(nse->iobuf)) == 0)
do_actual_pcap_read(nse);
}
/* if already received something */
if (fs_length(&(nse->iobuf)) > 0)
handle_pcap_read_result(nsp, nse, NSE_STATUS_SUCCESS);
if (event_timedout(nse))
handle_pcap_read_result(nsp, nse, NSE_STATUS_TIMEOUT);
#if PCAP_BSD_SELECT_HACK
/* If event occurred, and we're in BSD_HACK mode, then this event was added
* to two queues. read_event and pcap_read_event
* Of course we should destroy it only once.
* I assume we're now in read_event, so just unlink this event from
* pcap_read_event */
if (((mspcap *)nse->iod->pcap)->pcap_desc >= 0
&& nse->event_done
&& evlist == &nsp->read_events) {
/* event is done, list is read_events and we're in BSD_HACK mode.
* So unlink event from pcap_read_events */
update_first_events(nse);
gh_list_remove(&nsp->pcap_read_events, &nse->nodeq_pcap);
nsock_log_debug_all("PCAP NSE #%lu: Removing event from PCAP_READ_EVENTS",
nse->id);
}
if (((mspcap *)nse->iod->pcap)->pcap_desc >= 0
&& nse->event_done
&& evlist == &nsp->pcap_read_events) {
update_first_events(nse);
gh_list_remove(&nsp->read_events, &nse->nodeq_io);
nsock_log_debug_all("PCAP NSE #%lu: Removing event from READ_EVENTS",
nse->id);
}
#endif
break;
}
#endif
default:
fatal("Event has unknown type (%d)", nse->type);
}
}
if (nse->event_done) {
/* Security sanity check: don't return a functional SSL iod without
* setting an SSL data structure. */
if (nse->type == NSE_TYPE_CONNECT_SSL && nse->status == NSE_STATUS_SUCCESS)
assert(nse->iod->ssl != NULL);
nsock_log_debug_all("NSE #%lu: Sending event", nse->id);
/* WooHoo! The event is ready to be sent */
event_dispatch_and_delete(nsp, nse, 1);
}
}
void process_iod_events(struct npool *nsp, struct niod *nsi, int ev) {
int i = 0;
/* store addresses of the pointers to the first elements of each kind instead
* of storing the values, as a connect can add a read for instance */
gh_lnode_t **start_elems[] = {
&nsi->first_connect,
&nsi->first_read,
&nsi->first_write,
#if HAVE_PCAP
&nsi->first_pcap_read,
#endif
NULL
};
gh_list_t *evlists[] = {
&nsp->connect_events,
&nsp->read_events,
&nsp->write_events,
#if HAVE_PCAP
&nsp->pcap_read_events,
#endif
NULL
};
assert(nsp == nsi->nsp);
nsock_log_debug_all("Processing events on IOD %lu (ev=%d)", nsi->id, ev);
/* We keep the events separate because we want to handle them in the
* order: connect => read => write => timer for several reasons:
*
* 1) Makes sure we have gone through all the net i/o events before
* a timer expires (would be a shame to timeout after the data was
* available but before we delivered the events
*
* 2) The connect() results often lead to a read or write that can be
* processed in the same cycle. In the same way, read() often
* leads to write().
*/
for (i = 0; evlists[i] != NULL; i++) {
gh_lnode_t *current, *next, *last;
/* for each list, get the last event and don't look past it as an event
* could add another event in the same list and so on... */
last = gh_list_last_elem(evlists[i]);
for (current = *start_elems[i];
current != NULL && gh_lnode_prev(current) != last;
current = next) {
struct nevent *nse;
#if HAVE_PCAP
if (evlists[i] == &nsi->nsp->pcap_read_events)
nse = lnode_nevent2(current);
else
#endif
nse = lnode_nevent(current);
/* events are grouped by IOD. Break if we're done with the events for the
* current IOD */
if (nse->iod != nsi)
break;
process_event(nsp, evlists[i], nse, ev);
next = gh_lnode_next(current);
if (nse->event_done) {
/* event is done, remove it from the event list and update IOD pointers
* to the first events of each kind */
update_first_events(nse);
gh_list_remove(evlists[i], current);
gh_list_append(&nsp->free_events, &nse->nodeq_io);
if (nse->timeout.tv_sec)
gh_heap_remove(&nsp->expirables, &nse->expire);
}
}
}
}
static int nevent_unref(struct npool *nsp, struct nevent *nse) {
switch (nse->type) {
case NSE_TYPE_CONNECT:
case NSE_TYPE_CONNECT_SSL:
gh_list_remove(&nsp->connect_events, &nse->nodeq_io);
break;
case NSE_TYPE_READ:
gh_list_remove(&nsp->read_events, &nse->nodeq_io);
break;
case NSE_TYPE_WRITE:
gh_list_remove(&nsp->write_events, &nse->nodeq_io);
break;
#if HAVE_PCAP
case NSE_TYPE_PCAP_READ: {
char read = 0;
char pcap = 0;
#if PCAP_BSD_SELECT_HACK
read = pcap = 1;
#else
if (((mspcap *)nse->iod->pcap)->pcap_desc >= 0)
read = 1;
else
pcap = 1;
#endif /* PCAP_BSD_SELECT_HACK */
if (read)
gh_list_remove(&nsp->read_events, &nse->nodeq_io);
if (pcap)
gh_list_remove(&nsp->pcap_read_events, &nse->nodeq_pcap);
break;
}
#endif /* HAVE_PCAP */
case NSE_TYPE_TIMER:
/* Nothing to do */
break;
default:
fatal("Unknown event type %d", nse->type);
}
gh_list_append(&nsp->free_events, &nse->nodeq_io);
return 0;
}
void process_expired_events(struct npool *nsp) {
for (;;) {
gh_hnode_t *hnode;
struct nevent *nse;
hnode = gh_heap_min(&nsp->expirables);
if (!hnode)
break;
nse = container_of(hnode, struct nevent, expire);
if (!event_timedout(nse))
break;
gh_heap_remove(&nsp->expirables, hnode);
process_event(nsp, NULL, nse, EV_NONE);
assert(nse->event_done);
update_first_events(nse);
nevent_unref(nsp, nse);
}
}
/* Calling this function will cause nsock_loop to quit on its next iteration
* with a return value of NSOCK_LOOP_QUIT. */
void nsock_loop_quit(nsock_pool nsp) {
struct npool *ms = (struct npool *)nsp;
ms->quit = 1;
}
/* Grab the latest time as recorded by the nsock library, which does so at least
* once per event loop (in main_loop). Not only does this function (generally)
* avoid a system call, but in many circumstances it is better to use nsock's
* time rather than the system time. If nsock has never obtained the time when
* you call it, it will do so before returning */
const struct timeval *nsock_gettimeofday() {
if (nsock_tod.tv_sec == 0)
gettimeofday(&nsock_tod, NULL);
return &nsock_tod;
}
/* Adds an event to the appropriate nsp event list, handles housekeeping such as
* adjusting the descriptor select/poll lists, registering the timeout value,
* etc. */
void nsock_pool_add_event(struct npool *nsp, struct nevent *nse) {
nsock_log_debug("NSE #%lu: Adding event (timeout in %ldms)",
nse->id,
(long)TIMEVAL_MSEC_SUBTRACT(nse->timeout, nsock_tod));
nsp->events_pending++;
if (!nse->event_done && nse->timeout.tv_sec) {
/* This event is expirable, add it to the queue */
gh_heap_push(&nsp->expirables, &nse->expire);
}
/* Now we do the event type specific actions */
switch (nse->type) {
case NSE_TYPE_CONNECT:
case NSE_TYPE_CONNECT_SSL:
if (!nse->event_done) {
assert(nse->iod->sd >= 0);
socket_count_read_inc(nse->iod);
socket_count_write_inc(nse->iod);
update_events(nse->iod, nsp, nse, EV_READ|EV_WRITE, EV_NONE);
}
iod_add_event(nse->iod, nse);
break;
case NSE_TYPE_READ:
if (!nse->event_done) {
assert(nse->iod->sd >= 0);
socket_count_read_inc(nse->iod);
update_events(nse->iod, nsp, nse, EV_READ, EV_NONE);
#if HAVE_OPENSSL
if (nse->iod->ssl)
nse->sslinfo.ssl_desire = SSL_ERROR_WANT_READ;
#endif
}
iod_add_event(nse->iod, nse);
break;
case NSE_TYPE_WRITE:
if (!nse->event_done) {
assert(nse->iod->sd >= 0);
socket_count_write_inc(nse->iod);
update_events(nse->iod, nsp, nse, EV_WRITE, EV_NONE);
#if HAVE_OPENSSL
if (nse->iod->ssl)
nse->sslinfo.ssl_desire = SSL_ERROR_WANT_WRITE;
#endif
}
iod_add_event(nse->iod, nse);
break;
case NSE_TYPE_TIMER:
/* nothing to do */
break;
#if HAVE_PCAP
case NSE_TYPE_PCAP_READ: {
mspcap *mp = (mspcap *)nse->iod->pcap;
assert(mp);
if (mp->pcap_desc >= 0) { /* pcap descriptor present */
if (!nse->event_done) {
socket_count_readpcap_inc(nse->iod);
update_events(nse->iod, nsp, nse, EV_READ, EV_NONE);
}
nsock_log_debug_all("PCAP NSE #%lu: Adding event to READ_EVENTS", nse->id);
#if PCAP_BSD_SELECT_HACK
/* when using BSD hack we must do pcap_next() after select().
* Let's insert this pcap to bot queues, to selectable and nonselectable.
* This will result in doing pcap_next_ex() just before select() */
nsock_log_debug_all("PCAP NSE #%lu: Adding event to PCAP_READ_EVENTS", nse->id);
#endif
} else {
/* pcap isn't selectable. Add it to pcap-specific queue. */
nsock_log_debug_all("PCAP NSE #%lu: Adding event to PCAP_READ_EVENTS", nse->id);
}
iod_add_event(nse->iod, nse);
break;
}
#endif
default:
fatal("Unknown nsock event type (%d)", nse->type);
}
/* It can happen that the event already completed. In which case we can
* already deliver it, even though we're probably not inside nsock_loop(). */
if (nse->event_done) {
event_dispatch_and_delete(nsp, nse, 1);
update_first_events(nse);
nevent_unref(nsp, nse);
}
}
/* An event has been completed and the handler is about to be called. This
* function writes out tracing data about the event if necessary */
void nsock_trace_handler_callback(struct npool *ms, struct nevent *nse) {
struct niod *nsi;
char *str;
int strlength = 0;
char displaystr[256];
char errstr[256];
if (NsockLogLevel > NSOCK_LOG_INFO)
return;
nsi = nse->iod;
if (nse->status == NSE_STATUS_ERROR)
Snprintf(errstr, sizeof(errstr), "[%s (%d)] ", socket_strerror(nse->errnum),
nse->errnum);
else
errstr[0] = '\0';
/* Some types have special tracing treatment */
switch (nse->type) {
case NSE_TYPE_CONNECT:
case NSE_TYPE_CONNECT_SSL:
nsock_log_info("Callback: %s %s %sfor EID %li [%s]",
nse_type2str(nse->type), nse_status2str(nse->status),
errstr, nse->id, get_peeraddr_string(nsi));
break;
case NSE_TYPE_READ:
if (nse->status != NSE_STATUS_SUCCESS) {
nsock_log_info("Callback: %s %s %sfor EID %li [%s]",
nse_type2str(nse->type), nse_status2str(nse->status),
errstr, nse->id, get_peeraddr_string(nsi));
} else {
str = nse_readbuf(nse, &strlength);
if (strlength < 80) {
memcpy(displaystr, ": ", 2);
memcpy(displaystr + 2, str, strlength);
displaystr[2 + strlength] = '\0';
replacenonprintable(displaystr + 2, strlength, '.');
} else {
displaystr[0] = '\0';
}
nsock_log_info("Callback: %s %s for EID %li [%s] %s(%d bytes)%s",
nse_type2str(nse->type), nse_status2str(nse->status),
nse->id,
get_peeraddr_string(nsi),
nse_eof(nse) ? "[EOF]" : "", strlength, displaystr);
}
break;
case NSE_TYPE_WRITE:
nsock_log_info("Callback: %s %s %sfor EID %li [%s]",
nse_type2str(nse->type), nse_status2str(nse->status),
errstr, nse->id, get_peeraddr_string(nsi));
break;
case NSE_TYPE_TIMER:
nsock_log_info("Callback: %s %s %sfor EID %li",
nse_type2str(nse->type), nse_status2str(nse->status),
errstr, nse->id);
break;
#if HAVE_PCAP
case NSE_TYPE_PCAP_READ:
nsock_log_info("Callback: %s %s %sfor EID %li ",
nse_type2str(nse->type), nse_status2str(nse->status),
errstr, nse->id);
break;
#endif
default:
fatal("Invalid nsock event type (%d)", nse->type);
}
}