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144c10fad1
bird/sysdep/unix/io.c
Ondrej Zajicek (work) e40542ef3a Minor autoconf cleanup and documentation update
2017-05-16 12:59:22 +02:00

2666 lines
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/*
* BIRD Internet Routing Daemon -- Unix I/O
*
* (c) 1998--2004 Martin Mares <mj@ucw.cz>
* (c) 2004 Ondrej Filip <feela@network.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
/* Unfortunately, some glibc versions hide parts of RFC 3542 API
if _GNU_SOURCE is not defined. */
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <poll.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <netinet/icmp6.h>
#include "nest/bird.h"
#include "lib/lists.h"
#include "lib/resource.h"
#include "sysdep/unix/timer.h"
#include "lib/socket.h"
#include "lib/event.h"
#include "lib/string.h"
#include "nest/iface.h"
#include "sysdep/unix/unix.h"
#include CONFIG_INCLUDE_SYSIO_H
/* Maximum number of calls of tx handler for one socket in one
* poll iteration. Should be small enough to not monopolize CPU by
* one protocol instance.
*/
#define MAX_STEPS 4
/* Maximum number of calls of rx handler for all sockets in one poll
iteration. RX callbacks are often much more costly so we limit
this to gen small latencies */
#define MAX_RX_STEPS 4
/*
* Tracked Files
*/
struct rfile {
resource r;
FILE *f;
};
static void
rf_free(resource *r)
{
struct rfile *a = (struct rfile *) r;
fclose(a->f);
}
static void
rf_dump(resource *r)
{
struct rfile *a = (struct rfile *) r;
debug("(FILE *%p)\n", a->f);
}
static struct resclass rf_class = {
"FILE",
sizeof(struct rfile),
rf_free,
rf_dump,
NULL,
NULL
};
void *
tracked_fopen(pool *p, char *name, char *mode)
{
FILE *f = fopen(name, mode);
if (f)
{
struct rfile *r = ralloc(p, &rf_class);
r->f = f;
}
return f;
}
/**
* DOC: Timers
*
* Timers are resources which represent a wish of a module to call
* a function at the specified time. The platform dependent code
* doesn't guarantee exact timing, only that a timer function
* won't be called before the requested time.
*
* In BIRD, time is represented by values of the &bird_clock_t type
* which are integral numbers interpreted as a relative number of seconds since
* some fixed time point in past. The current time can be read
* from variable @now with reasonable accuracy and is monotonic. There is also
* a current 'absolute' time in variable @now_real reported by OS.
*
* Each timer is described by a &timer structure containing a pointer
* to the handler function (@hook), data private to this function (@data),
* time the function should be called at (@expires, 0 for inactive timers),
* for the other fields see |timer.h|.
*/
#define NEAR_TIMER_LIMIT 4
static list near_timers, far_timers;
static bird_clock_t first_far_timer = TIME_INFINITY;
/* now must be different from 0, because 0 is a special value in timer->expires */
bird_clock_t now = 1, now_real, boot_time;
static void
update_times_plain(void)
{
bird_clock_t new_time = time(NULL);
int delta = new_time - now_real;
if ((delta >= 0) && (delta < 60))
now += delta;
else if (now_real != 0)
log(L_WARN "Time jump, delta %d s", delta);
now_real = new_time;
}
static void
update_times_gettime(void)
{
struct timespec ts;
int rv;
rv = clock_gettime(CLOCK_MONOTONIC, &ts);
if (rv != 0)
die("clock_gettime: %m");
if (ts.tv_sec != now) {
if (ts.tv_sec < now)
log(L_ERR "Monotonic timer is broken");
now = ts.tv_sec;
now_real = time(NULL);
}
}
static int clock_monotonic_available;
static inline void
update_times(void)
{
if (clock_monotonic_available)
update_times_gettime();
else
update_times_plain();
}
static inline void
init_times(void)
{
struct timespec ts;
clock_monotonic_available = (clock_gettime(CLOCK_MONOTONIC, &ts) == 0);
if (!clock_monotonic_available)
log(L_WARN "Monotonic timer is missing");
}
static void
tm_free(resource *r)
{
timer *t = (timer *) r;
tm_stop(t);
}
static void
tm_dump(resource *r)
{
timer *t = (timer *) r;
debug("(code %p, data %p, ", t->hook, t->data);
if (t->randomize)
debug("rand %d, ", t->randomize);
if (t->recurrent)
debug("recur %d, ", t->recurrent);
if (t->expires)
debug("expires in %d sec)\n", t->expires - now);
else
debug("inactive)\n");
}
static struct resclass tm_class = {
"Timer",
sizeof(timer),
tm_free,
tm_dump,
NULL,
NULL
};
/**
* tm_new - create a timer
* @p: pool
*
* This function creates a new timer resource and returns
* a pointer to it. To use the timer, you need to fill in
* the structure fields and call tm_start() to start timing.
*/
timer *
tm_new(pool *p)
{
timer *t = ralloc(p, &tm_class);
return t;
}
static inline void
tm_insert_near(timer *t)
{
node *n = HEAD(near_timers);
while (n->next && (SKIP_BACK(timer, n, n)->expires < t->expires))
n = n->next;
insert_node(&t->n, n->prev);
}
/**
* tm_start - start a timer
* @t: timer
* @after: number of seconds the timer should be run after
*
* This function schedules the hook function of the timer to
* be called after @after seconds. If the timer has been already
* started, it's @expire time is replaced by the new value.
*
* You can have set the @randomize field of @t, the timeout
* will be increased by a random number of seconds chosen
* uniformly from range 0 .. @randomize.
*
* You can call tm_start() from the handler function of the timer
* to request another run of the timer. Also, you can set the @recurrent
* field to have the timer re-added automatically with the same timeout.
*/
void
tm_start(timer *t, unsigned after)
{
bird_clock_t when;
if (t->randomize)
after += random() % (t->randomize + 1);
when = now + after;
if (t->expires == when)
return;
if (t->expires)
rem_node(&t->n);
t->expires = when;
if (after <= NEAR_TIMER_LIMIT)
tm_insert_near(t);
else
{
if (!first_far_timer || first_far_timer > when)
first_far_timer = when;
add_tail(&far_timers, &t->n);
}
}
/**
* tm_stop - stop a timer
* @t: timer
*
* This function stops a timer. If the timer is already stopped,
* nothing happens.
*/
void
tm_stop(timer *t)
{
if (t->expires)
{
rem_node(&t->n);
t->expires = 0;
}
}
static void
tm_dump_them(char *name, list *l)
{
node *n;
timer *t;
debug("%s timers:\n", name);
WALK_LIST(n, *l)
{
t = SKIP_BACK(timer, n, n);
debug("%p ", t);
tm_dump(&t->r);
}
debug("\n");
}
void
tm_dump_all(void)
{
tm_dump_them("Near", &near_timers);
tm_dump_them("Far", &far_timers);
}
static inline time_t
tm_first_shot(void)
{
time_t x = first_far_timer;
if (!EMPTY_LIST(near_timers))
{
timer *t = SKIP_BACK(timer, n, HEAD(near_timers));
if (t->expires < x)
x = t->expires;
}
return x;
}
void io_log_event(void *hook, void *data);
static void
tm_shot(void)
{
timer *t;
node *n, *m;
if (first_far_timer <= now)
{
bird_clock_t limit = now + NEAR_TIMER_LIMIT;
first_far_timer = TIME_INFINITY;
n = HEAD(far_timers);
while (m = n->next)
{
t = SKIP_BACK(timer, n, n);
if (t->expires <= limit)
{
rem_node(n);
tm_insert_near(t);
}
else if (t->expires < first_far_timer)
first_far_timer = t->expires;
n = m;
}
}
while ((n = HEAD(near_timers)) -> next)
{
int delay;
t = SKIP_BACK(timer, n, n);
if (t->expires > now)
break;
rem_node(n);
delay = t->expires - now;
t->expires = 0;
if (t->recurrent)
{
int i = t->recurrent - delay;
if (i < 0)
i = 0;
tm_start(t, i);
}
io_log_event(t->hook, t->data);
t->hook(t);
}
}
/**
* tm_parse_datetime - parse a date and time
* @x: datetime string
*
* tm_parse_datetime() takes a textual representation of
* a date and time (dd-mm-yyyy hh:mm:ss)
* and converts it to the corresponding value of type &bird_clock_t.
*/
bird_clock_t
tm_parse_datetime(char *x)
{
struct tm tm;
int n;
time_t t;
if (sscanf(x, "%d-%d-%d %d:%d:%d%n", &tm.tm_mday, &tm.tm_mon, &tm.tm_year, &tm.tm_hour, &tm.tm_min, &tm.tm_sec, &n) != 6 || x[n])
return tm_parse_date(x);
tm.tm_mon--;
tm.tm_year -= 1900;
t = mktime(&tm);
if (t == (time_t) -1)
return 0;
return t;
}
/**
* tm_parse_date - parse a date
* @x: date string
*
* tm_parse_date() takes a textual representation of a date (dd-mm-yyyy)
* and converts it to the corresponding value of type &bird_clock_t.
*/
bird_clock_t
tm_parse_date(char *x)
{
struct tm tm;
int n;
time_t t;
if (sscanf(x, "%d-%d-%d%n", &tm.tm_mday, &tm.tm_mon, &tm.tm_year, &n) != 3 || x[n])
return 0;
tm.tm_mon--;
tm.tm_year -= 1900;
tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
t = mktime(&tm);
if (t == (time_t) -1)
return 0;
return t;
}
static void
tm_format_reltime(char *x, struct tm *tm, bird_clock_t delta)
{
static char *month_names[12] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
if (delta < 20*3600)
bsprintf(x, "%02d:%02d", tm->tm_hour, tm->tm_min);
else if (delta < 360*86400)
bsprintf(x, "%s%02d", month_names[tm->tm_mon], tm->tm_mday);
else
bsprintf(x, "%d", tm->tm_year+1900);
}
#include "conf/conf.h"
/**
* tm_format_datetime - convert date and time to textual representation
* @x: destination buffer of size %TM_DATETIME_BUFFER_SIZE
* @fmt_spec: specification of resulting textual representation of the time
* @t: time
*
* This function formats the given relative time value @t to a textual
* date/time representation (dd-mm-yyyy hh:mm:ss) in real time.
*/
void
tm_format_datetime(char *x, struct timeformat *fmt_spec, bird_clock_t t)
{
const char *fmt_used;
struct tm *tm;
bird_clock_t delta = now - t;
t = now_real - delta;
tm = localtime(&t);
if (fmt_spec->fmt1 == NULL)
return tm_format_reltime(x, tm, delta);
if ((fmt_spec->limit == 0) || (delta < fmt_spec->limit))
fmt_used = fmt_spec->fmt1;
else
fmt_used = fmt_spec->fmt2;
int rv = strftime(x, TM_DATETIME_BUFFER_SIZE, fmt_used, tm);
if (((rv == 0) && fmt_used[0]) || (rv == TM_DATETIME_BUFFER_SIZE))
strcpy(x, "<too-long>");
}
/**
* DOC: Sockets
*
* Socket resources represent network connections. Their data structure (&socket)
* contains a lot of fields defining the exact type of the socket, the local and
* remote addresses and ports, pointers to socket buffers and finally pointers to
* hook functions to be called when new data have arrived to the receive buffer
* (@rx_hook), when the contents of the transmit buffer have been transmitted
* (@tx_hook) and when an error or connection close occurs (@err_hook).
*
* Freeing of sockets from inside socket hooks is perfectly safe.
*/
#ifndef SOL_IP
#define SOL_IP IPPROTO_IP
#endif
#ifndef SOL_IPV6
#define SOL_IPV6 IPPROTO_IPV6
#endif
#ifndef SOL_ICMPV6
#define SOL_ICMPV6 IPPROTO_ICMPV6
#endif
/*
* Sockaddr helper functions
*/
static inline int UNUSED sockaddr_length(int af)
{ return (af == AF_INET) ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6); }
static inline void
sockaddr_fill4(struct sockaddr_in *sa, ip_addr a, uint port)
{
memset(sa, 0, sizeof(struct sockaddr_in));
#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
sa->sin_len = sizeof(struct sockaddr_in);
#endif
sa->sin_family = AF_INET;
sa->sin_port = htons(port);
sa->sin_addr = ipa_to_in4(a);
}
static inline void
sockaddr_fill6(struct sockaddr_in6 *sa, ip_addr a, struct iface *ifa, uint port)
{
memset(sa, 0, sizeof(struct sockaddr_in6));
#ifdef SIN6_LEN
sa->sin6_len = sizeof(struct sockaddr_in6);
#endif
sa->sin6_family = AF_INET6;
sa->sin6_port = htons(port);
sa->sin6_flowinfo = 0;
sa->sin6_addr = ipa_to_in6(a);
if (ifa && ipa_is_link_local(a))
sa->sin6_scope_id = ifa->index;
}
void
sockaddr_fill(sockaddr *sa, int af, ip_addr a, struct iface *ifa, uint port)
{
if (af == AF_INET)
sockaddr_fill4((struct sockaddr_in *) sa, a, port);
else if (af == AF_INET6)
sockaddr_fill6((struct sockaddr_in6 *) sa, a, ifa, port);
else
bug("Unknown AF");
}
static inline void
sockaddr_read4(struct sockaddr_in *sa, ip_addr *a, uint *port)
{
*port = ntohs(sa->sin_port);
*a = ipa_from_in4(sa->sin_addr);
}
static inline void
sockaddr_read6(struct sockaddr_in6 *sa, ip_addr *a, struct iface **ifa, uint *port)
{
*port = ntohs(sa->sin6_port);
*a = ipa_from_in6(sa->sin6_addr);
if (ifa && ipa_is_link_local(*a))
*ifa = if_find_by_index(sa->sin6_scope_id);
}
int
sockaddr_read(sockaddr *sa, int af, ip_addr *a, struct iface **ifa, uint *port)
{
if (sa->sa.sa_family != af)
goto fail;
if (af == AF_INET)
sockaddr_read4((struct sockaddr_in *) sa, a, port);
else if (af == AF_INET6)
sockaddr_read6((struct sockaddr_in6 *) sa, a, ifa, port);
else
goto fail;
return 0;
fail:
*a = IPA_NONE;
*port = 0;
return -1;
}
/*
* IPv6 multicast syscalls
*/
/* Fortunately standardized in RFC 3493 */
#define INIT_MREQ6(maddr,ifa) \
{ .ipv6mr_multiaddr = ipa_to_in6(maddr), .ipv6mr_interface = ifa->index }
static inline int
sk_setup_multicast6(sock *s)
{
int index = s->iface->index;
int ttl = s->ttl;
int n = 0;
if (setsockopt(s->fd, SOL_IPV6, IPV6_MULTICAST_IF, &index, sizeof(index)) < 0)
ERR("IPV6_MULTICAST_IF");
if (setsockopt(s->fd, SOL_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
ERR("IPV6_MULTICAST_HOPS");
if (setsockopt(s->fd, SOL_IPV6, IPV6_MULTICAST_LOOP, &n, sizeof(n)) < 0)
ERR("IPV6_MULTICAST_LOOP");
return 0;
}
static inline int
sk_join_group6(sock *s, ip_addr maddr)
{
struct ipv6_mreq mr = INIT_MREQ6(maddr, s->iface);
if (setsockopt(s->fd, SOL_IPV6, IPV6_JOIN_GROUP, &mr, sizeof(mr)) < 0)
ERR("IPV6_JOIN_GROUP");
return 0;
}
static inline int
sk_leave_group6(sock *s, ip_addr maddr)
{
struct ipv6_mreq mr = INIT_MREQ6(maddr, s->iface);
if (setsockopt(s->fd, SOL_IPV6, IPV6_LEAVE_GROUP, &mr, sizeof(mr)) < 0)
ERR("IPV6_LEAVE_GROUP");
return 0;
}
/*
* IPv6 packet control messages
*/
/* Also standardized, in RFC 3542 */
/*
* RFC 2292 uses IPV6_PKTINFO for both the socket option and the cmsg
* type, RFC 3542 changed the socket option to IPV6_RECVPKTINFO. If we
* don't have IPV6_RECVPKTINFO we suppose the OS implements the older
* RFC and we use IPV6_PKTINFO.
*/
#ifndef IPV6_RECVPKTINFO
#define IPV6_RECVPKTINFO IPV6_PKTINFO
#endif
/*
* Same goes for IPV6_HOPLIMIT -> IPV6_RECVHOPLIMIT.
*/
#ifndef IPV6_RECVHOPLIMIT
#define IPV6_RECVHOPLIMIT IPV6_HOPLIMIT
#endif
#define CMSG6_SPACE_PKTINFO CMSG_SPACE(sizeof(struct in6_pktinfo))
#define CMSG6_SPACE_TTL CMSG_SPACE(sizeof(int))
static inline int
sk_request_cmsg6_pktinfo(sock *s)
{
int y = 1;
if (setsockopt(s->fd, SOL_IPV6, IPV6_RECVPKTINFO, &y, sizeof(y)) < 0)
ERR("IPV6_RECVPKTINFO");
return 0;
}
static inline int
sk_request_cmsg6_ttl(sock *s)
{
int y = 1;
if (setsockopt(s->fd, SOL_IPV6, IPV6_RECVHOPLIMIT, &y, sizeof(y)) < 0)
ERR("IPV6_RECVHOPLIMIT");
return 0;
}
static inline void
sk_process_cmsg6_pktinfo(sock *s, struct cmsghdr *cm)
{
if (cm->cmsg_type == IPV6_PKTINFO)
{
struct in6_pktinfo *pi = (struct in6_pktinfo *) CMSG_DATA(cm);
s->laddr = ipa_from_in6(pi->ipi6_addr);
s->lifindex = pi->ipi6_ifindex;
}
}
static inline void
sk_process_cmsg6_ttl(sock *s, struct cmsghdr *cm)
{
if (cm->cmsg_type == IPV6_HOPLIMIT)
s->rcv_ttl = * (int *) CMSG_DATA(cm);
}
static inline void
sk_prepare_cmsgs6(sock *s, struct msghdr *msg, void *cbuf, size_t cbuflen)
{
struct cmsghdr *cm;
struct in6_pktinfo *pi;
int controllen = 0;
msg->msg_control = cbuf;
msg->msg_controllen = cbuflen;
cm = CMSG_FIRSTHDR(msg);
cm->cmsg_level = SOL_IPV6;
cm->cmsg_type = IPV6_PKTINFO;
cm->cmsg_len = CMSG_LEN(sizeof(*pi));
controllen += CMSG_SPACE(sizeof(*pi));
pi = (struct in6_pktinfo *) CMSG_DATA(cm);
pi->ipi6_ifindex = s->iface ? s->iface->index : 0;
pi->ipi6_addr = ipa_to_in6(s->saddr);
msg->msg_controllen = controllen;
}
/*
* Miscellaneous socket syscalls
*/
static inline int
sk_set_ttl4(sock *s, int ttl)
{
if (setsockopt(s->fd, SOL_IP, IP_TTL, &ttl, sizeof(ttl)) < 0)
ERR("IP_TTL");
return 0;
}
static inline int
sk_set_ttl6(sock *s, int ttl)
{
if (setsockopt(s->fd, SOL_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0)
ERR("IPV6_UNICAST_HOPS");
return 0;
}
static inline int
sk_set_tos4(sock *s, int tos)
{
if (setsockopt(s->fd, SOL_IP, IP_TOS, &tos, sizeof(tos)) < 0)
ERR("IP_TOS");
return 0;
}
static inline int
sk_set_tos6(sock *s, int tos)
{
if (setsockopt(s->fd, SOL_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
ERR("IPV6_TCLASS");
return 0;
}
static inline int
sk_set_high_port(sock *s UNUSED)
{
/* Port range setting is optional, ignore it if not supported */
#ifdef IP_PORTRANGE
if (sk_is_ipv4(s))
{
int range = IP_PORTRANGE_HIGH;
if (setsockopt(s->fd, SOL_IP, IP_PORTRANGE, &range, sizeof(range)) < 0)
ERR("IP_PORTRANGE");
}
#endif
#ifdef IPV6_PORTRANGE
if (sk_is_ipv6(s))
{
int range = IPV6_PORTRANGE_HIGH;
if (setsockopt(s->fd, SOL_IPV6, IPV6_PORTRANGE, &range, sizeof(range)) < 0)
ERR("IPV6_PORTRANGE");
}
#endif
return 0;
}
static inline byte *
sk_skip_ip_header(byte *pkt, int *len)
{
if ((*len < 20) || ((*pkt & 0xf0) != 0x40))
return NULL;
int hlen = (*pkt & 0x0f) * 4;
if ((hlen < 20) || (hlen > *len))
return NULL;
*len -= hlen;
return pkt + hlen;
}
byte *
sk_rx_buffer(sock *s, int *len)
{
if (sk_is_ipv4(s) && (s->type == SK_IP))
return sk_skip_ip_header(s->rbuf, len);
else
return s->rbuf;
}
/*
* Public socket functions
*/
/**
* sk_setup_multicast - enable multicast for given socket
* @s: socket
*
* Prepare transmission of multicast packets for given datagram socket.
* The socket must have defined @iface.
*
* Result: 0 for success, -1 for an error.
*/
int
sk_setup_multicast(sock *s)
{
ASSERT(s->iface);
if (sk_is_ipv4(s))
return sk_setup_multicast4(s);
else
return sk_setup_multicast6(s);
}
/**
* sk_join_group - join multicast group for given socket
* @s: socket
* @maddr: multicast address
*
* Join multicast group for given datagram socket and associated interface.
* The socket must have defined @iface.
*
* Result: 0 for success, -1 for an error.
*/
int
sk_join_group(sock *s, ip_addr maddr)
{
if (sk_is_ipv4(s))
return sk_join_group4(s, maddr);
else
return sk_join_group6(s, maddr);
}
/**
* sk_leave_group - leave multicast group for given socket
* @s: socket
* @maddr: multicast address
*
* Leave multicast group for given datagram socket and associated interface.
* The socket must have defined @iface.
*
* Result: 0 for success, -1 for an error.
*/
int
sk_leave_group(sock *s, ip_addr maddr)
{
if (sk_is_ipv4(s))
return sk_leave_group4(s, maddr);
else
return sk_leave_group6(s, maddr);
}
/**
* sk_setup_broadcast - enable broadcast for given socket
* @s: socket
*
* Allow reception and transmission of broadcast packets for given datagram
* socket. The socket must have defined @iface. For transmission, packets should
* be send to @brd address of @iface.
*
* Result: 0 for success, -1 for an error.
*/
int
sk_setup_broadcast(sock *s)
{
int y = 1;
if (setsockopt(s->fd, SOL_SOCKET, SO_BROADCAST, &y, sizeof(y)) < 0)
ERR("SO_BROADCAST");
return 0;
}
/**
* sk_set_ttl - set transmit TTL for given socket
* @s: socket
* @ttl: TTL value
*
* Set TTL for already opened connections when TTL was not set before. Useful
* for accepted connections when different ones should have different TTL.
*
* Result: 0 for success, -1 for an error.
*/
int
sk_set_ttl(sock *s, int ttl)
{
s->ttl = ttl;
if (sk_is_ipv4(s))
return sk_set_ttl4(s, ttl);
else
return sk_set_ttl6(s, ttl);
}
/**
* sk_set_min_ttl - set minimal accepted TTL for given socket
* @s: socket
* @ttl: TTL value
*
* Set minimal accepted TTL for given socket. Can be used for TTL security.
* implementations.
*
* Result: 0 for success, -1 for an error.
*/
int
sk_set_min_ttl(sock *s, int ttl)
{
if (sk_is_ipv4(s))
return sk_set_min_ttl4(s, ttl);
else
return sk_set_min_ttl6(s, ttl);
}
#if 0
/**
* sk_set_md5_auth - add / remove MD5 security association for given socket
* @s: socket
* @local: IP address of local side
* @remote: IP address of remote side
* @ifa: Interface for link-local IP address
* @passwd: Password used for MD5 authentication
* @setkey: Update also system SA/SP database
*
* In TCP MD5 handling code in kernel, there is a set of security associations
* used for choosing password and other authentication parameters according to
* the local and remote address. This function is useful for listening socket,
* for active sockets it may be enough to set s->password field.
*
* When called with passwd != NULL, the new pair is added,
* When called with passwd == NULL, the existing pair is removed.
*
* Note that while in Linux, the MD5 SAs are specific to socket, in BSD they are
* stored in global SA/SP database (but the behavior also must be enabled on
* per-socket basis). In case of multiple sockets to the same neighbor, the
* socket-specific state must be configured for each socket while global state
* just once per src-dst pair. The @setkey argument controls whether the global
* state (SA/SP database) is also updated.
*
* Result: 0 for success, -1 for an error.
*/
int
sk_set_md5_auth(sock *s, ip_addr local, ip_addr remote, struct iface *ifa, char *passwd, int setkey)
{ DUMMY; }
#endif
/**
* sk_set_ipv6_checksum - specify IPv6 checksum offset for given socket
* @s: socket
* @offset: offset
*
* Specify IPv6 checksum field offset for given raw IPv6 socket. After that, the
* kernel will automatically fill it for outgoing packets and check it for
* incoming packets. Should not be used on ICMPv6 sockets, where the position is
* known to the kernel.
*
* Result: 0 for success, -1 for an error.
*/
int
sk_set_ipv6_checksum(sock *s, int offset)
{
if (setsockopt(s->fd, SOL_IPV6, IPV6_CHECKSUM, &offset, sizeof(offset)) < 0)
ERR("IPV6_CHECKSUM");
return 0;
}
int
sk_set_icmp6_filter(sock *s, int p1, int p2)
{
/* a bit of lame interface, but it is here only for Radv */
struct icmp6_filter f;
ICMP6_FILTER_SETBLOCKALL(&f);
ICMP6_FILTER_SETPASS(p1, &f);
ICMP6_FILTER_SETPASS(p2, &f);
if (setsockopt(s->fd, SOL_ICMPV6, ICMP6_FILTER, &f, sizeof(f)) < 0)
ERR("ICMP6_FILTER");
return 0;
}
void
sk_log_error(sock *s, const char *p)
{
log(L_ERR "%s: Socket error: %s%#m", p, s->err);
}
/*
* Actual struct birdsock code
*/
static list sock_list;
static struct birdsock *current_sock;
static struct birdsock *stored_sock;
static inline sock *
sk_next(sock *s)
{
if (!s->n.next->next)
return NULL;
else
return SKIP_BACK(sock, n, s->n.next);
}
static void
sk_alloc_bufs(sock *s)
{
if (!s->rbuf && s->rbsize)
s->rbuf = s->rbuf_alloc = xmalloc(s->rbsize);
s->rpos = s->rbuf;
if (!s->tbuf && s->tbsize)
s->tbuf = s->tbuf_alloc = xmalloc(s->tbsize);
s->tpos = s->ttx = s->tbuf;
}
static void
sk_free_bufs(sock *s)
{
if (s->rbuf_alloc)
{
xfree(s->rbuf_alloc);
s->rbuf = s->rbuf_alloc = NULL;
}
if (s->tbuf_alloc)
{
xfree(s->tbuf_alloc);
s->tbuf = s->tbuf_alloc = NULL;
}
}
#ifdef HAVE_LIBSSH
static void
sk_ssh_free(sock *s)
{
struct ssh_sock *ssh = s->ssh;
if (s->ssh == NULL)
return;
s->ssh = NULL;
if (ssh->channel)
{
if (ssh_channel_is_open(ssh->channel))
ssh_channel_close(ssh->channel);
ssh_channel_free(ssh->channel);
ssh->channel = NULL;
}
if (ssh->session)
{
ssh_disconnect(ssh->session);
ssh_free(ssh->session);
ssh->session = NULL;
}
}
#endif
static void
sk_free(resource *r)
{
sock *s = (sock *) r;
sk_free_bufs(s);
#ifdef HAVE_LIBSSH
if (s->type == SK_SSH || s->type == SK_SSH_ACTIVE)
sk_ssh_free(s);
#endif
if (s->fd < 0)
return;
/* FIXME: we should call sk_stop() for SKF_THREAD sockets */
if (!(s->flags & SKF_THREAD))
{
if (s == current_sock)
current_sock = sk_next(s);
if (s == stored_sock)
stored_sock = sk_next(s);
rem_node(&s->n);
}
if (s->type != SK_SSH && s->type != SK_SSH_ACTIVE)
close(s->fd);
s->fd = -1;
}
void
sk_set_rbsize(sock *s, uint val)
{
ASSERT(s->rbuf_alloc == s->rbuf);
if (s->rbsize == val)
return;
s->rbsize = val;
xfree(s->rbuf_alloc);
s->rbuf_alloc = xmalloc(val);
s->rpos = s->rbuf = s->rbuf_alloc;
}
void
sk_set_tbsize(sock *s, uint val)
{
ASSERT(s->tbuf_alloc == s->tbuf);
if (s->tbsize == val)
return;
byte *old_tbuf = s->tbuf;
s->tbsize = val;
s->tbuf = s->tbuf_alloc = xrealloc(s->tbuf_alloc, val);
s->tpos = s->tbuf + (s->tpos - old_tbuf);
s->ttx = s->tbuf + (s->ttx - old_tbuf);
}
void
sk_set_tbuf(sock *s, void *tbuf)
{
s->tbuf = tbuf ?: s->tbuf_alloc;
s->ttx = s->tpos = s->tbuf;
}
void
sk_reallocate(sock *s)
{
sk_free_bufs(s);
sk_alloc_bufs(s);
}
static void
sk_dump(resource *r)
{
sock *s = (sock *) r;
static char *sk_type_names[] = { "TCP<", "TCP>", "TCP", "UDP", NULL, "IP", NULL, "MAGIC", "UNIX<", "UNIX", "SSH>", "SSH", "DEL!" };
debug("(%s, ud=%p, sa=%I, sp=%d, da=%I, dp=%d, tos=%d, ttl=%d, if=%s)\n",
sk_type_names[s->type],
s->data,
s->saddr,
s->sport,
s->daddr,
s->dport,
s->tos,
s->ttl,
s->iface ? s->iface->name : "none");
}
static struct resclass sk_class = {
"Socket",
sizeof(sock),
sk_free,
sk_dump,
NULL,
NULL
};
/**
* sk_new - create a socket
* @p: pool
*
* This function creates a new socket resource. If you want to use it,
* you need to fill in all the required fields of the structure and
* call sk_open() to do the actual opening of the socket.
*
* The real function name is sock_new(), sk_new() is a macro wrapper
* to avoid collision with OpenSSL.
*/
sock *
sock_new(pool *p)
{
sock *s = ralloc(p, &sk_class);
s->pool = p;
// s->saddr = s->daddr = IPA_NONE;
s->tos = s->priority = s->ttl = -1;
s->fd = -1;
return s;
}
static int
sk_setup(sock *s)
{
int y = 1;
int fd = s->fd;
if (s->type == SK_SSH_ACTIVE)
return 0;
if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
ERR("O_NONBLOCK");
if (!s->af)
return 0;
if (ipa_nonzero(s->saddr) && !(s->flags & SKF_BIND))
s->flags |= SKF_PKTINFO;
#ifdef CONFIG_USE_HDRINCL
if (sk_is_ipv4(s) && (s->type == SK_IP) && (s->flags & SKF_PKTINFO))
{
s->flags &= ~SKF_PKTINFO;
s->flags |= SKF_HDRINCL;
if (setsockopt(fd, SOL_IP, IP_HDRINCL, &y, sizeof(y)) < 0)
ERR("IP_HDRINCL");
}
#endif
if (s->iface)
{
#ifdef SO_BINDTODEVICE
struct ifreq ifr = {};
strcpy(ifr.ifr_name, s->iface->name);
if (setsockopt(s->fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) < 0)
ERR("SO_BINDTODEVICE");
#endif
#ifdef CONFIG_UNIX_DONTROUTE
if (setsockopt(s->fd, SOL_SOCKET, SO_DONTROUTE, &y, sizeof(y)) < 0)
ERR("SO_DONTROUTE");
#endif
}
if (s->priority >= 0)
if (sk_set_priority(s, s->priority) < 0)
return -1;
if (sk_is_ipv4(s))
{
if (s->flags & SKF_LADDR_RX)
if (sk_request_cmsg4_pktinfo(s) < 0)
return -1;
if (s->flags & SKF_TTL_RX)
if (sk_request_cmsg4_ttl(s) < 0)
return -1;
if ((s->type == SK_UDP) || (s->type == SK_IP))
if (sk_disable_mtu_disc4(s) < 0)
return -1;
if (s->ttl >= 0)
if (sk_set_ttl4(s, s->ttl) < 0)
return -1;
if (s->tos >= 0)
if (sk_set_tos4(s, s->tos) < 0)
return -1;
}
if (sk_is_ipv6(s))
{
if ((s->type == SK_TCP_PASSIVE) || (s->type == SK_TCP_ACTIVE) || (s->type == SK_UDP))
if (setsockopt(fd, SOL_IPV6, IPV6_V6ONLY, &y, sizeof(y)) < 0)
ERR("IPV6_V6ONLY");
if (s->flags & SKF_LADDR_RX)
if (sk_request_cmsg6_pktinfo(s) < 0)
return -1;
if (s->flags & SKF_TTL_RX)
if (sk_request_cmsg6_ttl(s) < 0)
return -1;
if ((s->type == SK_UDP) || (s->type == SK_IP))
if (sk_disable_mtu_disc6(s) < 0)
return -1;
if (s->ttl >= 0)
if (sk_set_ttl6(s, s->ttl) < 0)
return -1;
if (s->tos >= 0)
if (sk_set_tos6(s, s->tos) < 0)
return -1;
}
return 0;
}
static void
sk_insert(sock *s)
{
add_tail(&sock_list, &s->n);
}
static void
sk_tcp_connected(sock *s)
{
sockaddr sa;
int sa_len = sizeof(sa);
if ((getsockname(s->fd, &sa.sa, &sa_len) < 0) ||
(sockaddr_read(&sa, s->af, &s->saddr, &s->iface, &s->sport) < 0))
log(L_WARN "SOCK: Cannot get local IP address for TCP>");
s->type = SK_TCP;
sk_alloc_bufs(s);
s->tx_hook(s);
}
static void
sk_ssh_connected(sock *s)
{
sk_alloc_bufs(s);
s->type = SK_SSH;
s->tx_hook(s);
}
static int
sk_passive_connected(sock *s, int type)
{
sockaddr loc_sa, rem_sa;
int loc_sa_len = sizeof(loc_sa);
int rem_sa_len = sizeof(rem_sa);
int fd = accept(s->fd, ((type == SK_TCP) ? &rem_sa.sa : NULL), &rem_sa_len);
if (fd < 0)
{
if ((errno != EINTR) && (errno != EAGAIN))
s->err_hook(s, errno);
return 0;
}
sock *t = sk_new(s->pool);
t->type = type;
t->af = s->af;
t->fd = fd;
t->ttl = s->ttl;
t->tos = s->tos;
t->rbsize = s->rbsize;
t->tbsize = s->tbsize;
if (type == SK_TCP)
{
if ((getsockname(fd, &loc_sa.sa, &loc_sa_len) < 0) ||
(sockaddr_read(&loc_sa, s->af, &t->saddr, &t->iface, &t->sport) < 0))
log(L_WARN "SOCK: Cannot get local IP address for TCP<");
if (sockaddr_read(&rem_sa, s->af, &t->daddr, &t->iface, &t->dport) < 0)
log(L_WARN "SOCK: Cannot get remote IP address for TCP<");
}
if (sk_setup(t) < 0)
{
/* FIXME: Call err_hook instead ? */
log(L_ERR "SOCK: Incoming connection: %s%#m", t->err);
/* FIXME: handle it better in rfree() */
close(t->fd);
t->fd = -1;
rfree(t);
return 1;
}
sk_insert(t);
sk_alloc_bufs(t);
s->rx_hook(t, 0);
return 1;
}
#ifdef HAVE_LIBSSH
/*
* Return SSH_OK or SSH_AGAIN or SSH_ERROR
*/
static int
sk_ssh_connect(sock *s)
{
s->fd = ssh_get_fd(s->ssh->session);
/* Big fall thru automata */
switch (s->ssh->state)
{
case SK_SSH_CONNECT:
{
switch (ssh_connect(s->ssh->session))
{
case SSH_AGAIN:
/* A quick look into libSSH shows that ssh_get_fd() should return non-(-1)
* after SSH_AGAIN is returned by ssh_connect(). This is however nowhere
* documented but our code relies on that.
*/
return SSH_AGAIN;
case SSH_OK:
break;
default:
return SSH_ERROR;
}
}
case SK_SSH_SERVER_KNOWN:
{
s->ssh->state = SK_SSH_SERVER_KNOWN;
if (s->ssh->server_hostkey_path)
{
int server_identity_is_ok = 1;
/* Check server identity */
switch (ssh_is_server_known(s->ssh->session))
{
#define LOG_WARN_ABOUT_SSH_SERVER_VALIDATION(s,msg,args...) log(L_WARN "SSH Identity %s@%s:%u: " msg, (s)->ssh->username, (s)->host, (s)->dport, ## args);
case SSH_SERVER_KNOWN_OK:
/* The server is known and has not changed. */
break;
case SSH_SERVER_NOT_KNOWN:
LOG_WARN_ABOUT_SSH_SERVER_VALIDATION(s, "The server is unknown, its public key was not found in the known host file %s", s->ssh->server_hostkey_path);
break;
case SSH_SERVER_KNOWN_CHANGED:
LOG_WARN_ABOUT_SSH_SERVER_VALIDATION(s, "The server key has changed. Either you are under attack or the administrator changed the key.");
server_identity_is_ok = 0;
break;
case SSH_SERVER_FILE_NOT_FOUND:
LOG_WARN_ABOUT_SSH_SERVER_VALIDATION(s, "The known host file %s does not exist", s->ssh->server_hostkey_path);
server_identity_is_ok = 0;
break;
case SSH_SERVER_ERROR:
LOG_WARN_ABOUT_SSH_SERVER_VALIDATION(s, "Some error happened");
server_identity_is_ok = 0;
break;
case SSH_SERVER_FOUND_OTHER:
LOG_WARN_ABOUT_SSH_SERVER_VALIDATION(s, "The server gave use a key of a type while we had an other type recorded. " \
"It is a possible attack.");
server_identity_is_ok = 0;
break;
}
if (!server_identity_is_ok)
return SSH_ERROR;
}
}
case SK_SSH_USERAUTH:
{
s->ssh->state = SK_SSH_USERAUTH;
switch (ssh_userauth_publickey_auto(s->ssh->session, NULL, NULL))
{
case SSH_AUTH_AGAIN:
return SSH_AGAIN;
case SSH_AUTH_SUCCESS:
break;
default:
return SSH_ERROR;
}
}
case SK_SSH_CHANNEL:
{
s->ssh->state = SK_SSH_CHANNEL;
s->ssh->channel = ssh_channel_new(s->ssh->session);
if (s->ssh->channel == NULL)
return SSH_ERROR;
}
case SK_SSH_SESSION:
{
s->ssh->state = SK_SSH_SESSION;
switch (ssh_channel_open_session(s->ssh->channel))
{
case SSH_AGAIN:
return SSH_AGAIN;
case SSH_OK:
break;
default:
return SSH_ERROR;
}
}
case SK_SSH_SUBSYSTEM:
{
s->ssh->state = SK_SSH_SUBSYSTEM;
if (s->ssh->subsystem)
{
switch (ssh_channel_request_subsystem(s->ssh->channel, s->ssh->subsystem))
{
case SSH_AGAIN:
return SSH_AGAIN;
case SSH_OK:
break;
default:
return SSH_ERROR;
}
}
}
case SK_SSH_ESTABLISHED:
s->ssh->state = SK_SSH_ESTABLISHED;
}
return SSH_OK;
}
/*
* Return file descriptor number if success
* Return -1 if failed
*/
static int
sk_open_ssh(sock *s)
{
if (!s->ssh)
bug("sk_open() sock->ssh is not allocated");
ssh_session sess = ssh_new();
if (sess == NULL)
ERR2("Cannot create a ssh session");
s->ssh->session = sess;
const int verbosity = SSH_LOG_NOLOG;
ssh_options_set(sess, SSH_OPTIONS_LOG_VERBOSITY, &verbosity);
ssh_options_set(sess, SSH_OPTIONS_HOST, s->host);
ssh_options_set(sess, SSH_OPTIONS_PORT, &(s->dport));
/* TODO: Add SSH_OPTIONS_BINDADDR */
ssh_options_set(sess, SSH_OPTIONS_USER, s->ssh->username);
if (s->ssh->server_hostkey_path)
ssh_options_set(sess, SSH_OPTIONS_KNOWNHOSTS, s->ssh->server_hostkey_path);
if (s->ssh->client_privkey_path)
ssh_options_set(sess, SSH_OPTIONS_IDENTITY, s->ssh->client_privkey_path);
ssh_set_blocking(sess, 0);
switch (sk_ssh_connect(s))
{
case SSH_AGAIN:
break;
case SSH_OK:
sk_ssh_connected(s);
break;
case SSH_ERROR:
ERR2(ssh_get_error(sess));
break;
}
return ssh_get_fd(sess);
err:
return -1;
}
#endif
/**
* sk_open - open a socket
* @s: socket
*
* This function takes a socket resource created by sk_new() and
* initialized by the user and binds a corresponding network connection
* to it.
*
* Result: 0 for success, -1 for an error.
*/
int
sk_open(sock *s)
{
int af = AF_UNSPEC;
int fd = -1;
int do_bind = 0;
int bind_port = 0;
ip_addr bind_addr = IPA_NONE;
sockaddr sa;
if (s->type <= SK_IP)
{
/*
* For TCP/IP sockets, Address family (IPv4 or IPv6) can be specified either
* explicitly (SK_IPV4 or SK_IPV6) or implicitly (based on saddr, daddr).
* But the specifications have to be consistent.
*/
switch (s->subtype)
{
case 0:
ASSERT(ipa_zero(s->saddr) || ipa_zero(s->daddr) ||
(ipa_is_ip4(s->saddr) == ipa_is_ip4(s->daddr)));
af = (ipa_is_ip4(s->saddr) || ipa_is_ip4(s->daddr)) ? AF_INET : AF_INET6;
break;
case SK_IPV4:
ASSERT(ipa_zero(s->saddr) || ipa_is_ip4(s->saddr));
ASSERT(ipa_zero(s->daddr) || ipa_is_ip4(s->daddr));
af = AF_INET;
break;
case SK_IPV6:
ASSERT(ipa_zero(s->saddr) || !ipa_is_ip4(s->saddr));
ASSERT(ipa_zero(s->daddr) || !ipa_is_ip4(s->daddr));
af = AF_INET6;
break;
default:
bug("Invalid subtype %d", s->subtype);
}
}
switch (s->type)
{
case SK_TCP_ACTIVE:
s->ttx = ""; /* Force s->ttx != s->tpos */
/* Fall thru */
case SK_TCP_PASSIVE:
fd = socket(af, SOCK_STREAM, IPPROTO_TCP);
bind_port = s->sport;
bind_addr = s->saddr;
do_bind = bind_port || ipa_nonzero(bind_addr);
break;
#ifdef HAVE_LIBSSH
case SK_SSH_ACTIVE:
s->ttx = ""; /* Force s->ttx != s->tpos */
fd = sk_open_ssh(s);
break;
#endif
case SK_UDP:
fd = socket(af, SOCK_DGRAM, IPPROTO_UDP);
bind_port = s->sport;
bind_addr = (s->flags & SKF_BIND) ? s->saddr : IPA_NONE;
do_bind = 1;
break;
case SK_IP:
fd = socket(af, SOCK_RAW, s->dport);
bind_port = 0;
bind_addr = (s->flags & SKF_BIND) ? s->saddr : IPA_NONE;
do_bind = ipa_nonzero(bind_addr);
break;
case SK_MAGIC:
af = 0;
fd = s->fd;
break;
default:
bug("sk_open() called for invalid sock type %d", s->type);
}
if (fd < 0)
ERR("socket");
s->af = af;
s->fd = fd;
if (sk_setup(s) < 0)
goto err;
if (do_bind)
{
if (bind_port)
{
int y = 1;
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &y, sizeof(y)) < 0)
ERR2("SO_REUSEADDR");
#ifdef CONFIG_NO_IFACE_BIND
/* Workaround missing ability to bind to an iface */
if ((s->type == SK_UDP) && s->iface && ipa_zero(bind_addr))
{
if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &y, sizeof(y)) < 0)
ERR2("SO_REUSEPORT");
}
#endif
}
else
if (s->flags & SKF_HIGH_PORT)
if (sk_set_high_port(s) < 0)
log(L_WARN "Socket error: %s%#m", s->err);
sockaddr_fill(&sa, s->af, bind_addr, s->iface, bind_port);
if (bind(fd, &sa.sa, SA_LEN(sa)) < 0)
ERR2("bind");
}
if (s->password)
if (sk_set_md5_auth(s, s->saddr, s->daddr, s->iface, s->password, 0) < 0)
goto err;
switch (s->type)
{
case SK_TCP_ACTIVE:
sockaddr_fill(&sa, s->af, s->daddr, s->iface, s->dport);
if (connect(fd, &sa.sa, SA_LEN(sa)) >= 0)
sk_tcp_connected(s);
else if (errno != EINTR && errno != EAGAIN && errno != EINPROGRESS &&
errno != ECONNREFUSED && errno != EHOSTUNREACH && errno != ENETUNREACH)
ERR2("connect");
break;
case SK_TCP_PASSIVE:
if (listen(fd, 8) < 0)
ERR2("listen");
break;
case SK_SSH_ACTIVE:
case SK_MAGIC:
break;
default:
sk_alloc_bufs(s);
}
if (!(s->flags & SKF_THREAD))
sk_insert(s);
return 0;
err:
close(fd);
s->fd = -1;
return -1;
}
int
sk_open_unix(sock *s, char *name)
{
struct sockaddr_un sa;
int fd;
/* We are sloppy during error (leak fd and not set s->err), but we die anyway */
fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (fd < 0)
return -1;
if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
return -1;
/* Path length checked in test_old_bird() */
sa.sun_family = AF_UNIX;
strcpy(sa.sun_path, name);
if (bind(fd, (struct sockaddr *) &sa, SUN_LEN(&sa)) < 0)
return -1;
if (listen(fd, 8) < 0)
return -1;
s->fd = fd;
sk_insert(s);
return 0;
}
#define CMSG_RX_SPACE MAX(CMSG4_SPACE_PKTINFO+CMSG4_SPACE_TTL, \
CMSG6_SPACE_PKTINFO+CMSG6_SPACE_TTL)
#define CMSG_TX_SPACE MAX(CMSG4_SPACE_PKTINFO,CMSG6_SPACE_PKTINFO)
static void
sk_prepare_cmsgs(sock *s, struct msghdr *msg, void *cbuf, size_t cbuflen)
{
if (sk_is_ipv4(s))
sk_prepare_cmsgs4(s, msg, cbuf, cbuflen);
else
sk_prepare_cmsgs6(s, msg, cbuf, cbuflen);
}
static void
sk_process_cmsgs(sock *s, struct msghdr *msg)
{
struct cmsghdr *cm;
s->laddr = IPA_NONE;
s->lifindex = 0;
s->rcv_ttl = -1;
for (cm = CMSG_FIRSTHDR(msg); cm != NULL; cm = CMSG_NXTHDR(msg, cm))
{
if ((cm->cmsg_level == SOL_IP) && sk_is_ipv4(s))
{
sk_process_cmsg4_pktinfo(s, cm);
sk_process_cmsg4_ttl(s, cm);
}
if ((cm->cmsg_level == SOL_IPV6) && sk_is_ipv6(s))
{
sk_process_cmsg6_pktinfo(s, cm);
sk_process_cmsg6_ttl(s, cm);
}
}
}
static inline int
sk_sendmsg(sock *s)
{
struct iovec iov = {s->tbuf, s->tpos - s->tbuf};
byte cmsg_buf[CMSG_TX_SPACE];
sockaddr dst;
sockaddr_fill(&dst, s->af, s->daddr, s->iface, s->dport);
struct msghdr msg = {
.msg_name = &dst.sa,
.msg_namelen = SA_LEN(dst),
.msg_iov = &iov,
.msg_iovlen = 1
};
#ifdef CONFIG_USE_HDRINCL
byte hdr[20];
struct iovec iov2[2] = { {hdr, 20}, iov };
if (s->flags & SKF_HDRINCL)
{
sk_prepare_ip_header(s, hdr, iov.iov_len);
msg.msg_iov = iov2;
msg.msg_iovlen = 2;
}
#endif
if (s->flags & SKF_PKTINFO)
sk_prepare_cmsgs(s, &msg, cmsg_buf, sizeof(cmsg_buf));
return sendmsg(s->fd, &msg, 0);
}
static inline int
sk_recvmsg(sock *s)
{
struct iovec iov = {s->rbuf, s->rbsize};
byte cmsg_buf[CMSG_RX_SPACE];
sockaddr src;
struct msghdr msg = {
.msg_name = &src.sa,
.msg_namelen = sizeof(src), // XXXX ??
.msg_iov = &iov,
.msg_iovlen = 1,
.msg_control = cmsg_buf,
.msg_controllen = sizeof(cmsg_buf),
.msg_flags = 0
};
int rv = recvmsg(s->fd, &msg, 0);
if (rv < 0)
return rv;
//ifdef IPV4
// if (cf_type == SK_IP)
// rv = ipv4_skip_header(pbuf, rv);
//endif
sockaddr_read(&src, s->af, &s->faddr, NULL, &s->fport);
sk_process_cmsgs(s, &msg);
if (msg.msg_flags & MSG_TRUNC)
s->flags |= SKF_TRUNCATED;
else
s->flags &= ~SKF_TRUNCATED;
return rv;
}
static inline void reset_tx_buffer(sock *s) { s->ttx = s->tpos = s->tbuf; }
static int
sk_maybe_write(sock *s)
{
int e;
switch (s->type)
{
case SK_TCP:
case SK_MAGIC:
case SK_UNIX:
while (s->ttx != s->tpos)
{
e = write(s->fd, s->ttx, s->tpos - s->ttx);
if (e < 0)
{
if (errno != EINTR && errno != EAGAIN)
{
reset_tx_buffer(s);
/* EPIPE is just a connection close notification during TX */
s->err_hook(s, (errno != EPIPE) ? errno : 0);
return -1;
}
return 0;
}
s->ttx += e;
}
reset_tx_buffer(s);
return 1;
#ifdef HAVE_LIBSSH
case SK_SSH:
while (s->ttx != s->tpos)
{
e = ssh_channel_write(s->ssh->channel, s->ttx, s->tpos - s->ttx);
if (e < 0)
{
s->err = ssh_get_error(s->ssh->session);
s->err_hook(s, ssh_get_error_code(s->ssh->session));
reset_tx_buffer(s);
/* EPIPE is just a connection close notification during TX */
s->err_hook(s, (errno != EPIPE) ? errno : 0);
return -1;
}
s->ttx += e;
}
reset_tx_buffer(s);
return 1;
#endif
case SK_UDP:
case SK_IP:
{
if (s->tbuf == s->tpos)
return 1;
e = sk_sendmsg(s);
if (e < 0)
{
if (errno != EINTR && errno != EAGAIN)
{
reset_tx_buffer(s);
s->err_hook(s, errno);
return -1;
}
if (!s->tx_hook)
reset_tx_buffer(s);
return 0;
}
reset_tx_buffer(s);
return 1;
}
default:
bug("sk_maybe_write: unknown socket type %d", s->type);
}
}
int
sk_rx_ready(sock *s)
{
int rv;
struct pollfd pfd = { .fd = s->fd };
pfd.events |= POLLIN;
redo:
rv = poll(&pfd, 1, 0);
if ((rv < 0) && (errno == EINTR || errno == EAGAIN))
goto redo;
return rv;
}
/**
* sk_send - send data to a socket
* @s: socket
* @len: number of bytes to send
*
* This function sends @len bytes of data prepared in the
* transmit buffer of the socket @s to the network connection.
* If the packet can be sent immediately, it does so and returns
* 1, else it queues the packet for later processing, returns 0
* and calls the @tx_hook of the socket when the tranmission
* takes place.
*/
int
sk_send(sock *s, unsigned len)
{
s->ttx = s->tbuf;
s->tpos = s->tbuf + len;
return sk_maybe_write(s);
}
/**
* sk_send_to - send data to a specific destination
* @s: socket
* @len: number of bytes to send
* @addr: IP address to send the packet to
* @port: port to send the packet to
*
* This is a sk_send() replacement for connection-less packet sockets
* which allows destination of the packet to be chosen dynamically.
* Raw IP sockets should use 0 for @port.
*/
int
sk_send_to(sock *s, unsigned len, ip_addr addr, unsigned port)
{
s->daddr = addr;
if (port)
s->dport = port;
s->ttx = s->tbuf;
s->tpos = s->tbuf + len;
return sk_maybe_write(s);
}
/*
int
sk_send_full(sock *s, unsigned len, struct iface *ifa,
ip_addr saddr, ip_addr daddr, unsigned dport)
{
s->iface = ifa;
s->saddr = saddr;
s->daddr = daddr;
s->dport = dport;
s->ttx = s->tbuf;
s->tpos = s->tbuf + len;
return sk_maybe_write(s);
}
*/
static void
call_rx_hook(sock *s, int size)
{
if (s->rx_hook(s, size))
{
/* We need to be careful since the socket could have been deleted by the hook */
if (current_sock == s)
s->rpos = s->rbuf;
}
}
#ifdef HAVE_LIBSSH
static int
sk_read_ssh(sock *s)
{
ssh_channel rchans[2] = { s->ssh->channel, NULL };
struct timeval timev = { 1, 0 };
if (ssh_channel_select(rchans, NULL, NULL, &timev) == SSH_EINTR)
return 1; /* Try again */
if (ssh_channel_is_eof(s->ssh->channel) != 0)
{
/* The remote side is closing the connection */
s->err_hook(s, 0);
return 0;
}
if (rchans[0] == NULL)
return 0; /* No data is available on the socket */
const uint used_bytes = s->rpos - s->rbuf;
const int read_bytes = ssh_channel_read_nonblocking(s->ssh->channel, s->rpos, s->rbsize - used_bytes, 0);
if (read_bytes > 0)
{
/* Received data */
s->rpos += read_bytes;
call_rx_hook(s, used_bytes + read_bytes);
return 1;
}
else if (read_bytes == 0)
{
if (ssh_channel_is_eof(s->ssh->channel) != 0)
{
/* The remote side is closing the connection */
s->err_hook(s, 0);
}
}
else
{
s->err = ssh_get_error(s->ssh->session);
s->err_hook(s, ssh_get_error_code(s->ssh->session));
}
return 0; /* No data is available on the socket */
}
#endif
/* sk_read() and sk_write() are called from BFD's event loop */
int
sk_read(sock *s, int revents)
{
switch (s->type)
{
case SK_TCP_PASSIVE:
return sk_passive_connected(s, SK_TCP);
case SK_UNIX_PASSIVE:
return sk_passive_connected(s, SK_UNIX);
case SK_TCP:
case SK_UNIX:
{
int c = read(s->fd, s->rpos, s->rbuf + s->rbsize - s->rpos);
if (c < 0)
{
if (errno != EINTR && errno != EAGAIN)
s->err_hook(s, errno);
else if (errno == EAGAIN && !(revents & POLLIN))
{
log(L_ERR "Got EAGAIN from read when revents=%x (without POLLIN)", revents);
s->err_hook(s, 0);
}
}
else if (!c)
s->err_hook(s, 0);
else
{
s->rpos += c;
call_rx_hook(s, s->rpos - s->rbuf);
return 1;
}
return 0;
}
#ifdef HAVE_LIBSSH
case SK_SSH:
return sk_read_ssh(s);
#endif
case SK_MAGIC:
return s->rx_hook(s, 0);
default:
{
int e = sk_recvmsg(s);
if (e < 0)
{
if (errno != EINTR && errno != EAGAIN)
s->err_hook(s, errno);
return 0;
}
s->rpos = s->rbuf + e;
s->rx_hook(s, e);
return 1;
}
}
}
int
sk_write(sock *s)
{
switch (s->type)
{
case SK_TCP_ACTIVE:
{
sockaddr sa;
sockaddr_fill(&sa, s->af, s->daddr, s->iface, s->dport);
if (connect(s->fd, &sa.sa, SA_LEN(sa)) >= 0 || errno == EISCONN)
sk_tcp_connected(s);
else if (errno != EINTR && errno != EAGAIN && errno != EINPROGRESS)
s->err_hook(s, errno);
return 0;
}
#ifdef HAVE_LIBSSH
case SK_SSH_ACTIVE:
{
switch (sk_ssh_connect(s))
{
case SSH_OK:
sk_ssh_connected(s);
break;
case SSH_AGAIN:
return 1;
case SSH_ERROR:
s->err = ssh_get_error(s->ssh->session);
s->err_hook(s, ssh_get_error_code(s->ssh->session));
break;
}
return 0;
}
#endif
default:
if (s->ttx != s->tpos && sk_maybe_write(s) > 0)
{
if (s->tx_hook)
s->tx_hook(s);
return 1;
}
return 0;
}
}
int sk_is_ipv4(sock *s)
{ return s->af == AF_INET; }
int sk_is_ipv6(sock *s)
{ return s->af == AF_INET6; }
void
sk_err(sock *s, int revents)
{
int se = 0, sse = sizeof(se);
if ((s->type != SK_MAGIC) && (revents & POLLERR))
if (getsockopt(s->fd, SOL_SOCKET, SO_ERROR, &se, &sse) < 0)
{
log(L_ERR "IO: Socket error: SO_ERROR: %m");
se = 0;
}
s->err_hook(s, se);
}
void
sk_dump_all(void)
{
node *n;
sock *s;
debug("Open sockets:\n");
WALK_LIST(n, sock_list)
{
s = SKIP_BACK(sock, n, n);
debug("%p ", s);
sk_dump(&s->r);
}
debug("\n");
}
/*
* Internal event log and watchdog
*/
#define EVENT_LOG_LENGTH 32
struct event_log_entry
{
void *hook;
void *data;
btime timestamp;
btime duration;
};
static struct event_log_entry event_log[EVENT_LOG_LENGTH];
static struct event_log_entry *event_open;
static int event_log_pos, event_log_num, watchdog_active;
static btime last_time;
static btime loop_time;
static void
io_update_time(void)
{
struct timespec ts;
int rv;
if (!clock_monotonic_available)
return;
/*
* This is third time-tracking procedure (after update_times() above and
* times_update() in BFD), dedicated to internal event log and latency
* tracking. Hopefully, we consolidate these sometimes.
*/
rv = clock_gettime(CLOCK_MONOTONIC, &ts);
if (rv < 0)
die("clock_gettime: %m");
last_time = ((s64) ts.tv_sec S) + (ts.tv_nsec / 1000);
if (event_open)
{
event_open->duration = last_time - event_open->timestamp;
if (event_open->duration > config->latency_limit)
log(L_WARN "Event 0x%p 0x%p took %d ms",
event_open->hook, event_open->data, (int) (event_open->duration TO_MS));
event_open = NULL;
}
}
/**
* io_log_event - mark approaching event into event log
* @hook: event hook address
* @data: event data address
*
* Store info (hook, data, timestamp) about the following internal event into
* a circular event log (@event_log). When latency tracking is enabled, the log
* entry is kept open (in @event_open) so the duration can be filled later.
*/
void
io_log_event(void *hook, void *data)
{
if (config->latency_debug)
io_update_time();
struct event_log_entry *en = event_log + event_log_pos;
en->hook = hook;
en->data = data;
en->timestamp = last_time;
en->duration = 0;
event_log_num++;
event_log_pos++;
event_log_pos %= EVENT_LOG_LENGTH;
event_open = config->latency_debug ? en : NULL;
}
static inline void
io_close_event(void)
{
if (event_open)
io_update_time();
}
void
io_log_dump(void)
{
int i;
log(L_DEBUG "Event log:");
for (i = 0; i < EVENT_LOG_LENGTH; i++)
{
struct event_log_entry *en = event_log + (event_log_pos + i) % EVENT_LOG_LENGTH;
if (en->hook)
log(L_DEBUG " Event 0x%p 0x%p at %8d for %d ms", en->hook, en->data,
(int) ((last_time - en->timestamp) TO_MS), (int) (en->duration TO_MS));
}
}
void
watchdog_sigalrm(int sig UNUSED)
{
/* Update last_time and duration, but skip latency check */
config->latency_limit = 0xffffffff;
io_update_time();
/* We want core dump */
abort();
}
static inline void
watchdog_start1(void)
{
io_update_time();
loop_time = last_time;
}
static inline void
watchdog_start(void)
{
io_update_time();
loop_time = last_time;
event_log_num = 0;
if (config->watchdog_timeout)
{
alarm(config->watchdog_timeout);
watchdog_active = 1;
}
}
static inline void
watchdog_stop(void)
{
io_update_time();
if (watchdog_active)
{
alarm(0);
watchdog_active = 0;
}
btime duration = last_time - loop_time;
if (duration > config->watchdog_warning)
log(L_WARN "I/O loop cycle took %d ms for %d events",
(int) (duration TO_MS), event_log_num);
}
/*
* Main I/O Loop
*/
volatile int async_config_flag; /* Asynchronous reconfiguration/dump scheduled */
volatile int async_dump_flag;
volatile int async_shutdown_flag;
void
io_init(void)
{
init_list(&near_timers);
init_list(&far_timers);
init_list(&sock_list);
init_list(&global_event_list);
krt_io_init();
init_times();
update_times();
boot_time = now;
srandom((int) now_real);
}
static int short_loops = 0;
#define SHORT_LOOP_MAX 10
void
io_loop(void)
{
int poll_tout;
time_t tout;
int nfds, events, pout;
sock *s;
node *n;
int fdmax = 256;
struct pollfd *pfd = xmalloc(fdmax * sizeof(struct pollfd));
watchdog_start1();
for(;;)
{
events = ev_run_list(&global_event_list);
timers:
update_times();
tout = tm_first_shot();
if (tout <= now)
{
tm_shot();
goto timers;
}
poll_tout = (events ? 0 : MIN(tout - now, 3)) * 1000; /* Time in milliseconds */
io_close_event();
nfds = 0;
WALK_LIST(n, sock_list)
{
pfd[nfds] = (struct pollfd) { .fd = -1 }; /* everything other set to 0 by this */
s = SKIP_BACK(sock, n, n);
if (s->rx_hook)
{
pfd[nfds].fd = s->fd;
pfd[nfds].events |= POLLIN;
}
if (s->tx_hook && s->ttx != s->tpos)
{
pfd[nfds].fd = s->fd;
pfd[nfds].events |= POLLOUT;
}
if (pfd[nfds].fd != -1)
{
s->index = nfds;
nfds++;
}
else
s->index = -1;
if (nfds >= fdmax)
{
fdmax *= 2;
pfd = xrealloc(pfd, fdmax * sizeof(struct pollfd));
}
}
/*
* Yes, this is racy. But even if the signal comes before this test
* and entering poll(), it gets caught on the next timer tick.
*/
if (async_config_flag)
{
io_log_event(async_config, NULL);
async_config();
async_config_flag = 0;
continue;
}
if (async_dump_flag)
{
io_log_event(async_dump, NULL);
async_dump();
async_dump_flag = 0;
continue;
}
if (async_shutdown_flag)
{
io_log_event(async_shutdown, NULL);
async_shutdown();
async_shutdown_flag = 0;
continue;
}
/* And finally enter poll() to find active sockets */
watchdog_stop();
pout = poll(pfd, nfds, poll_tout);
watchdog_start();
if (pout < 0)
{
if (errno == EINTR || errno == EAGAIN)
continue;
die("poll: %m");
}
if (pout)
{
/* guaranteed to be non-empty */
current_sock = SKIP_BACK(sock, n, HEAD(sock_list));
while (current_sock)
{
sock *s = current_sock;
if (s->index == -1)
{
current_sock = sk_next(s);
goto next;
}
int e;
int steps;
steps = MAX_STEPS;
if (s->fast_rx && (pfd[s->index].revents & POLLIN) && s->rx_hook)
do
{
steps--;
io_log_event(s->rx_hook, s->data);
e = sk_read(s, pfd[s->index].revents);
if (s != current_sock)
goto next;
}
while (e && s->rx_hook && steps);
steps = MAX_STEPS;
if (pfd[s->index].revents & POLLOUT)
do
{
steps--;
io_log_event(s->tx_hook, s->data);
e = sk_write(s);
if (s != current_sock)
goto next;
}
while (e && steps);
current_sock = sk_next(s);
next: ;
}
short_loops++;
if (events && (short_loops < SHORT_LOOP_MAX))
continue;
short_loops = 0;
int count = 0;
current_sock = stored_sock;
if (current_sock == NULL)
current_sock = SKIP_BACK(sock, n, HEAD(sock_list));
while (current_sock && count < MAX_RX_STEPS)
{
sock *s = current_sock;
if (s->index == -1)
{
current_sock = sk_next(s);
goto next2;
}
if (!s->fast_rx && (pfd[s->index].revents & POLLIN) && s->rx_hook)
{
count++;
io_log_event(s->rx_hook, s->data);
sk_read(s, pfd[s->index].revents);
if (s != current_sock)
goto next2;
}
if (pfd[s->index].revents & (POLLHUP | POLLERR))
{
sk_err(s, pfd[s->index].revents);
if (s != current_sock)
goto next2;
}
current_sock = sk_next(s);
next2: ;
}
stored_sock = current_sock;
}
}
}
void
test_old_bird(char *path)
{
int fd;
struct sockaddr_un sa;
fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (fd < 0)
die("Cannot create socket: %m");
if (strlen(path) >= sizeof(sa.sun_path))
die("Socket path too long");
bzero(&sa, sizeof(sa));
sa.sun_family = AF_UNIX;
strcpy(sa.sun_path, path);
if (connect(fd, (struct sockaddr *) &sa, SUN_LEN(&sa)) == 0)
die("I found another BIRD running.");
close(fd);
}
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