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Files
nmap/nsock/src/engine_poll.c
henri b55ff2d68f Don't associate nsock logging info to a nspool.
Make current loglevel and current log callback global
to the library. Attaching them to the nsock pool doesn't
bring any benefit and prevents from logging activity in
code sections that don't have access to a pool (such as
proxy chain specification parsing).

Updated external calls and nsock tests accordingly.
2015-06-27 08:21:53 +00:00

428 lines
13 KiB
C

/***************************************************************************
* engine_poll.c -- poll(2) based IO engine. *
* *
***********************IMPORTANT NSOCK LICENSE TERMS***********************
* *
* The nsock parallel socket event library is (C) 1999-2015 Insecure.Com *
* 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, Insecure.Com LLC *
* may be willing to sell alternative licenses (contact *
* sales@insecure.com ). *
* *
* As a special exception to the GPL terms, Insecure.Com 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 *
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* *
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* *
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* *
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* to the dev@nmap.org mailing list for possible incorporation into the *
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* occasionally relicense the code to third parties as discussed above. *
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* This program is distributed in the hope that it will be useful, but *
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* *
***************************************************************************/
/* $Id$ */
#ifndef WIN32
/* Allow the use of POLLRDHUP, if available. */
#define _GNU_SOURCE
#endif
#ifdef HAVE_CONFIG_H
#include "nsock_config.h"
#elif WIN32
#include "nsock_winconfig.h"
#endif
#if HAVE_POLL
#include <errno.h>
#ifndef WIN32
#include <poll.h>
#else
#include <Winsock2.h>
#endif /* ^WIN32 */
#include "nsock_internal.h"
#include "nsock_log.h"
#if HAVE_PCAP
#include "nsock_pcap.h"
#endif
#define EV_LIST_INIT_SIZE 1024
#ifdef WIN32
#define Poll WSAPoll
#define POLLFD WSAPOLLFD
#else
#define Poll poll
#define POLLFD struct pollfd
#endif
#ifdef WIN32
#define POLL_R_FLAGS (POLLIN)
#else
#define POLL_R_FLAGS (POLLIN | POLLPRI)
#endif /* WIN32 */
#define POLL_W_FLAGS POLLOUT
#ifdef POLLRDHUP
#define POLL_X_FLAGS (POLLERR | POLLHUP | POLLRDHUP)
#else
/* POLLRDHUP was introduced later and might be unavailable on older systems. */
#define POLL_X_FLAGS (POLLERR | POLLHUP)
#endif /* POLLRDHUP */
/* --- ENGINE INTERFACE PROTOTYPES --- */
static int poll_init(struct npool *nsp);
static void poll_destroy(struct npool *nsp);
static int poll_iod_register(struct npool *nsp, struct niod *iod, int ev);
static int poll_iod_unregister(struct npool *nsp, struct niod *iod);
static int poll_iod_modify(struct npool *nsp, struct niod *iod, int ev_set, int ev_clr);
static int poll_loop(struct npool *nsp, int msec_timeout);
/* ---- ENGINE DEFINITION ---- */
struct io_engine engine_poll = {
"poll",
poll_init,
poll_destroy,
poll_iod_register,
poll_iod_unregister,
poll_iod_modify,
poll_loop
};
/* --- INTERNAL PROTOTYPES --- */
static void iterate_through_event_lists(struct npool *nsp);
/* defined in nsock_core.c */
void process_iod_events(struct npool *nsp, struct niod *nsi, int ev);
void process_event(struct npool *nsp, gh_list_t *evlist, struct nevent *nse, int ev);
void process_expired_events(struct npool *nsp);
#if HAVE_PCAP
#ifndef PCAP_CAN_DO_SELECT
int pcap_read_on_nonselect(struct npool *nsp);
#endif
#endif
/* defined in nsock_event.c */
void update_first_events(struct nevent *nse);
extern struct timeval nsock_tod;
/*
* Engine specific data structure
*/
struct poll_engine_info {
int capacity;
int max_fd;
/* index of the highest poll event */
POLLFD *events;
};
static inline int lower_max_fd(struct poll_engine_info *pinfo) {
do {
pinfo->max_fd--;
} while (pinfo->max_fd >= 0 && pinfo->events[pinfo->max_fd].fd == -1);
return pinfo->max_fd;
}
static inline int evlist_grow(struct poll_engine_info *pinfo) {
int i;
i = pinfo->capacity;
if (pinfo->capacity == 0) {
pinfo->capacity = EV_LIST_INIT_SIZE;
pinfo->events = (POLLFD *)safe_malloc(sizeof(POLLFD) * pinfo->capacity);
} else {
pinfo->capacity *= 2;
pinfo->events = (POLLFD *)safe_realloc(pinfo->events, sizeof(POLLFD) * pinfo->capacity);
}
while (i < pinfo->capacity) {
pinfo->events[i].fd = -1;
pinfo->events[i].events = 0;
pinfo->events[i].revents = 0;
i++;
}
return pinfo->capacity;
}
int poll_init(struct npool *nsp) {
struct poll_engine_info *pinfo;
pinfo = (struct poll_engine_info *)safe_malloc(sizeof(struct poll_engine_info));
pinfo->capacity = 0;
pinfo->max_fd = -1;
evlist_grow(pinfo);
nsp->engine_data = (void *)pinfo;
return 1;
}
void poll_destroy(struct npool *nsp) {
struct poll_engine_info *pinfo = (struct poll_engine_info *)nsp->engine_data;
assert(pinfo != NULL);
free(pinfo->events);
free(pinfo);
}
int poll_iod_register(struct npool *nsp, struct niod *iod, int ev) {
struct poll_engine_info *pinfo = (struct poll_engine_info *)nsp->engine_data;
int sd;
assert(!IOD_PROPGET(iod, IOD_REGISTERED));
iod->watched_events = ev;
sd = nsock_iod_get_sd(iod);
while (pinfo->capacity < sd + 1)
evlist_grow(pinfo);
pinfo->events[sd].fd = sd;
pinfo->events[sd].events = 0;
pinfo->events[sd].revents = 0;
pinfo->max_fd = MAX(pinfo->max_fd, sd);
if (ev & EV_READ)
pinfo->events[sd].events |= POLL_R_FLAGS;
if (ev & EV_WRITE)
pinfo->events[sd].events |= POLL_W_FLAGS;
#ifndef WIN32
if (ev & EV_EXCEPT)
pinfo->events[sd].events |= POLL_X_FLAGS;
#endif
IOD_PROPSET(iod, IOD_REGISTERED);
return 1;
}
int poll_iod_unregister(struct npool *nsp, struct niod *iod) {
iod->watched_events = EV_NONE;
/* some IODs can be unregistered here if they're associated to an event that was
* immediately completed */
if (IOD_PROPGET(iod, IOD_REGISTERED)) {
struct poll_engine_info *pinfo = (struct poll_engine_info *)nsp->engine_data;
int sd;
sd = nsock_iod_get_sd(iod);
pinfo->events[sd].fd = -1;
pinfo->events[sd].events = 0;
pinfo->events[sd].revents = 0;
if (pinfo->max_fd == sd)
lower_max_fd(pinfo);
IOD_PROPCLR(iod, IOD_REGISTERED);
}
return 1;
}
int poll_iod_modify(struct npool *nsp, struct niod *iod, int ev_set, int ev_clr) {
int sd;
int new_events;
struct poll_engine_info *pinfo = (struct poll_engine_info *)nsp->engine_data;
assert((ev_set & ev_clr) == 0);
assert(IOD_PROPGET(iod, IOD_REGISTERED));
new_events = iod->watched_events;
new_events |= ev_set;
new_events &= ~ev_clr;
if (new_events == iod->watched_events)
return 1; /* nothing to do */
iod->watched_events = new_events;
sd = nsock_iod_get_sd(iod);
pinfo->events[sd].fd = sd;
pinfo->events[sd].events = 0;
/* regenerate the current set of events for this IOD */
if (iod->watched_events & EV_READ)
pinfo->events[sd].events |= POLL_R_FLAGS;
if (iod->watched_events & EV_WRITE)
pinfo->events[sd].events |= POLL_W_FLAGS;
#ifndef WIN32
if (iod->watched_events & EV_EXCEPT)
pinfo->events[sd].events |= POLL_X_FLAGS;
#endif
return 1;
}
int poll_loop(struct npool *nsp, int msec_timeout) {
int results_left = 0;
int event_msecs; /* msecs before an event goes off */
int combined_msecs;
int sock_err = 0;
struct poll_engine_info *pinfo = (struct poll_engine_info *)nsp->engine_data;
assert(msec_timeout >= -1);
if (nsp->events_pending == 0)
return 0; /* No need to wait on 0 events ... */
do {
struct nevent *nse;
nsock_log_debug_all("wait for events");
nse = next_expirable_event(nsp);
if (!nse)
event_msecs = -1; /* None of the events specified a timeout */
else
event_msecs = MAX(0, TIMEVAL_MSEC_SUBTRACT(nse->timeout, nsock_tod));
#if HAVE_PCAP
#ifndef PCAP_CAN_DO_SELECT
/* Force a low timeout when capturing packets on systems where
* the pcap descriptor is not select()able. */
if (gh_list_count(&nsp->pcap_read_events) > 0)
if (event_msecs > PCAP_POLL_INTERVAL)
event_msecs = PCAP_POLL_INTERVAL;
#endif
#endif
/* We cast to unsigned because we want -1 to be very high (since it means no
* timeout) */
combined_msecs = MIN((unsigned)event_msecs, (unsigned)msec_timeout);
#if HAVE_PCAP
#ifndef PCAP_CAN_DO_SELECT
/* do non-blocking read on pcap devices that doesn't support select()
* If there is anything read, just leave this loop. */
if (pcap_read_on_nonselect(nsp)) {
/* okay, something was read. */
} else
#endif
#endif
{
results_left = Poll(pinfo->events, pinfo->max_fd + 1, combined_msecs);
if (results_left == -1)
sock_err = socket_errno();
}
gettimeofday(&nsock_tod, NULL); /* Due to poll delay */
} while (results_left == -1 && sock_err == EINTR); /* repeat only if signal occurred */
if (results_left == -1 && sock_err != EINTR) {
nsock_log_error("nsock_loop error %d: %s", sock_err, socket_strerror(sock_err));
nsp->errnum = sock_err;
return -1;
}
iterate_through_event_lists(nsp);
return 1;
}
/* ---- INTERNAL FUNCTIONS ---- */
static inline int get_evmask(struct npool *nsp, struct niod *nsi) {
struct poll_engine_info *pinfo = (struct poll_engine_info *)nsp->engine_data;
int sd, evmask = EV_NONE;
POLLFD *pev;
if (nsi->state != NSIOD_STATE_DELETED
&& nsi->events_pending
&& IOD_PROPGET(nsi, IOD_REGISTERED)) {
#if HAVE_PCAP
if (nsi->pcap)
sd = ((mspcap *)nsi->pcap)->pcap_desc;
else
#endif
sd = nsi->sd;
assert(sd < pinfo->capacity);
pev = &pinfo->events[sd];
if (pev->revents & POLL_R_FLAGS)
evmask |= EV_READ;
if (pev->revents & POLL_W_FLAGS)
evmask |= EV_WRITE;
if (pev->events && (pev->revents & POLL_X_FLAGS))
evmask |= (EV_READ | EV_WRITE | EV_EXCEPT);
}
return evmask;
}
/* Iterate through all the event lists (such as connect_events, read_events,
* timer_events, etc) and take action for those that have completed (due to
* timeout, i/o, etc) */
void iterate_through_event_lists(struct npool *nsp) {
gh_lnode_t *current, *next, *last;
last = gh_list_last_elem(&nsp->active_iods);
for (current = gh_list_first_elem(&nsp->active_iods);
current != NULL && gh_lnode_prev(current) != last;
current = next) {
struct niod *nsi = container_of(current, struct niod, nodeq);
process_iod_events(nsp, nsi, get_evmask(nsp, nsi));
next = gh_lnode_next(current);
if (nsi->state == NSIOD_STATE_DELETED) {
gh_list_remove(&nsp->active_iods, current);
gh_list_prepend(&nsp->free_iods, current);
}
}
/* iterate through timers and expired events */
process_expired_events(nsp);
}
#endif /* HAVE_POLL */