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router: create ICMPv6 socket per interface
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Get rid of the global raw ICMPv6 socket by creating a raw ICMPv6 socket per
interface. This fixes an open raw ICMPv6 socket in case all ra interfaces
are configured as disabled.

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
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@dedeckeh
dedeckeh committed Apr 5, 2019
1 parent e7b1d4b commit c6dae8e
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Showing 3 changed files with 132 additions and 111 deletions.
1 change: 1 addition & 0 deletions src/config.c
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Original file line number Diff line number Diff line change
Expand Up @@ -430,6 +430,7 @@ int config_parse_interface(void *data, size_t len, const char *name, bool overwr

iface->name = strcpy(new_name, name);
iface->avl.key = iface->name;
iface->router_event.uloop.fd = -1;
iface->dhcpv6_event.uloop.fd = -1;
iface->ndp_event.uloop.fd = -1;
iface->dhcpv4_event.uloop.fd = -1;
Expand Down
1 change: 1 addition & 0 deletions src/odhcpd.h
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Original file line number Diff line number Diff line change
Expand Up @@ -209,6 +209,7 @@ struct interface {
size_t addr6_len;

// RA runtime data
struct odhcpd_event router_event;
struct uloop_timeout timer_rs;

// DHCPv6 runtime data
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241 changes: 130 additions & 111 deletions src/router.c
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Original file line number Diff line number Diff line change
Expand Up @@ -38,7 +38,6 @@ static void handle_icmpv6(void *addr, void *data, size_t len,
static void trigger_router_advert(struct uloop_timeout *event);
static void router_netevent_cb(unsigned long event, struct netevent_handler_info *info);

static struct odhcpd_event router_event = {.uloop = {.fd = -1}, .handle_dgram = handle_icmpv6, };
static struct netevent_handler router_netevent_handler = { .cb = router_netevent_cb, };

static FILE *fp_route = NULL;
Expand All @@ -48,78 +47,8 @@ static FILE *fp_route = NULL;

int router_init(void)
{
struct icmp6_filter filt;
int ret = 0;

/* Open ICMPv6 socket */
router_event.uloop.fd = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC, IPPROTO_ICMPV6);
if (router_event.uloop.fd < 0) {
syslog(LOG_ERR, "socket(AF_INET6): %m");
ret = -1;
goto out;
}

/* Let the kernel compute our checksums */
int val = 2;
if (setsockopt(router_event.uloop.fd, IPPROTO_RAW, IPV6_CHECKSUM,
&val, sizeof(val)) < 0) {
syslog(LOG_ERR, "setsockopt(IPV6_CHECKSUM): %m");
ret = -1;
goto out;
}

/* This is required by RFC 4861 */
val = 255;
if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
&val, sizeof(val)) < 0) {
syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_HOPS): %m");
ret = -1;
goto out;
}

if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
&val, sizeof(val)) < 0) {
syslog(LOG_ERR, "setsockopt(IPV6_UNICAST_HOPS): %m");
ret = -1;
goto out;
}

/* We need to know the source interface */
val = 1;
if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_RECVPKTINFO,
&val, sizeof(val)) < 0) {
syslog(LOG_ERR, "setsockopt(IPV6_RECVPKTINFO): %m");
ret = -1;
goto out;
}

if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT,
&val, sizeof(val)) < 0) {
syslog(LOG_ERR, "setsockopt(IPV6_RECVHOPLIMIT): %m");
ret = -1;
goto out;
}

/* Don't loop back */
val = 0;
if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
&val, sizeof(val)) < 0) {
syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_LOOP): %m");
ret = -1;
goto out;
}

/* Filter ICMPv6 package types */
ICMP6_FILTER_SETBLOCKALL(&filt);
ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
if (setsockopt(router_event.uloop.fd, IPPROTO_ICMPV6, ICMP6_FILTER,
&filt, sizeof(filt)) < 0) {
syslog(LOG_ERR, "setsockopt(ICMP6_FILTER): %m");
ret = -1;
goto out;
}

if (!(fp_route = fopen("/proc/net/ipv6_route", "r"))) {
syslog(LOG_ERR, "fopen(/proc/net/ipv6_route): %m");
ret = -1;
Expand All @@ -129,22 +58,12 @@ int router_init(void)
if (netlink_add_netevent_handler(&router_netevent_handler) < 0) {
syslog(LOG_ERR, "Failed to add netevent handler");
ret = -1;
goto out;
}

/* Register socket */
odhcpd_register(&router_event);
out:
if (ret < 0) {
if (router_event.uloop.fd > 0) {
close(router_event.uloop.fd);
router_event.uloop.fd = -1;
}

if (fp_route) {
fclose(fp_route);
fp_route = NULL;
}
if (ret < 0 && fp_route) {
fclose(fp_route);
fp_route = NULL;
}

return ret;
Expand All @@ -153,48 +72,149 @@ int router_init(void)

int router_setup_interface(struct interface *iface, bool enable)
{
struct ipv6_mreq mreq;
int ret = 0;

if (!fp_route || router_event.uloop.fd < 0) {
if (!fp_route) {
ret = -1;
goto out;
}

uloop_timeout_cancel(&iface->timer_rs);
iface->timer_rs.cb = NULL;

memset(&mreq, 0, sizeof(mreq));
mreq.ipv6mr_interface = iface->ifindex;
inet_pton(AF_INET6, ALL_IPV6_NODES, &mreq.ipv6mr_multiaddr);
setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
&mreq, sizeof(mreq));
if ((!enable || iface->ra == MODE_DISABLED) && iface->router_event.uloop.fd >= 0) {
if (!iface->master) {
uloop_timeout_cancel(&iface->timer_rs);
iface->timer_rs.cb = NULL;

inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &mreq.ipv6mr_multiaddr);
setsockopt(router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
&mreq, sizeof(mreq));

if (!enable) {
if (iface->ra == MODE_SERVER || (iface->ra == MODE_RELAY && !iface->master))
trigger_router_advert(&iface->timer_rs);
} else {
}

uloop_fd_delete(&iface->router_event.uloop);
close(iface->router_event.uloop.fd);
iface->router_event.uloop.fd = -1;
} else if (enable && iface->ra != MODE_DISABLED) {
struct icmp6_filter filt;
struct ipv6_mreq mreq;
int val = 2;

if (iface->router_event.uloop.fd < 0) {
/* Open ICMPv6 socket */
iface->router_event.uloop.fd = socket(AF_INET6, SOCK_RAW | SOCK_CLOEXEC,
IPPROTO_ICMPV6);
if (iface->router_event.uloop.fd < 0) {
syslog(LOG_ERR, "socket(AF_INET6): %m");
ret = -1;
goto out;
}

if (setsockopt(iface->router_event.uloop.fd, SOL_SOCKET, SO_BINDTODEVICE,
iface->ifname, strlen(iface->ifname)) < 0) {
syslog(LOG_ERR, "setsockopt(SO_BINDTODEVICE): %m");
ret = -1;
goto out;
}

/* Let the kernel compute our checksums */
if (setsockopt(iface->router_event.uloop.fd, IPPROTO_RAW, IPV6_CHECKSUM,
&val, sizeof(val)) < 0) {
syslog(LOG_ERR, "setsockopt(IPV6_CHECKSUM): %m");
ret = -1;
goto out;
}

/* This is required by RFC 4861 */
val = 255;
if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
&val, sizeof(val)) < 0) {
syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_HOPS): %m");
ret = -1;
goto out;
}

if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS,
&val, sizeof(val)) < 0) {
syslog(LOG_ERR, "setsockopt(IPV6_UNICAST_HOPS): %m");
ret = -1;
goto out;
}

/* We need to know the source interface */
val = 1;
if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_RECVPKTINFO,
&val, sizeof(val)) < 0) {
syslog(LOG_ERR, "setsockopt(IPV6_RECVPKTINFO): %m");
ret = -1;
goto out;
}

if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT,
&val, sizeof(val)) < 0) {
syslog(LOG_ERR, "setsockopt(IPV6_RECVHOPLIMIT): %m");
ret = -1;
goto out;
}

/* Don't loop back */
val = 0;
if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
&val, sizeof(val)) < 0) {
syslog(LOG_ERR, "setsockopt(IPV6_MULTICAST_LOOP): %m");
ret = -1;
goto out;
}

/* Filter ICMPv6 package types */
ICMP6_FILTER_SETBLOCKALL(&filt);
ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
ICMP6_FILTER_SETPASS(ND_ROUTER_SOLICIT, &filt);
if (setsockopt(iface->router_event.uloop.fd, IPPROTO_ICMPV6, ICMP6_FILTER,
&filt, sizeof(filt)) < 0) {
syslog(LOG_ERR, "setsockopt(ICMP6_FILTER): %m");
ret = -1;
goto out;
}

iface->router_event.handle_dgram = handle_icmpv6;
odhcpd_register(&iface->router_event);
} else {
uloop_timeout_cancel(&iface->timer_rs);
iface->timer_rs.cb = NULL;

memset(&mreq, 0, sizeof(mreq));
mreq.ipv6mr_interface = iface->ifindex;
inet_pton(AF_INET6, ALL_IPV6_NODES, &mreq.ipv6mr_multiaddr);
setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
&mreq, sizeof(mreq));

inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &mreq.ipv6mr_multiaddr);
setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP,
&mreq, sizeof(mreq));
}

memset(&mreq, 0, sizeof(mreq));
mreq.ipv6mr_interface = iface->ifindex;
inet_pton(AF_INET6, ALL_IPV6_ROUTERS, &mreq.ipv6mr_multiaddr);

if (iface->ra == MODE_RELAY && iface->master) {
inet_pton(AF_INET6, ALL_IPV6_NODES, &mreq.ipv6mr_multiaddr);
forward_router_solicitation(iface);
} else if (iface->ra == MODE_SERVER && !iface->master) {
} else if (iface->ra == MODE_SERVER) {
iface->timer_rs.cb = trigger_router_advert;
uloop_timeout_set(&iface->timer_rs, 1000);
}

if (iface->ra == MODE_RELAY || (iface->ra == MODE_SERVER && !iface->master)) {
if (setsockopt(router_event.uloop.fd, IPPROTO_IPV6,
IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
ret = -1;
syslog(LOG_ERR, "setsockopt(IPV6_ADD_MEMBERSHIP): %m");
}
if (setsockopt(iface->router_event.uloop.fd, IPPROTO_IPV6,
IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
ret = -1;
syslog(LOG_ERR, "setsockopt(IPV6_ADD_MEMBERSHIP): %m");
goto out;
}
}
out:
if (ret < 0 && iface->router_event.uloop.fd >= 0) {
close(iface->router_event.uloop.fd);
iface->router_event.uloop.fd = -1;
}

return ret;
}

Expand Down Expand Up @@ -677,8 +697,7 @@ static uint64_t send_router_advert(struct interface *iface, const struct in6_add

syslog(LOG_INFO, "Sending a RA on %s", iface->name);

odhcpd_send(router_event.uloop.fd,
&dest, iov, ARRAY_SIZE(iov), iface);
odhcpd_send(iface->router_event.uloop.fd, &dest, iov, ARRAY_SIZE(iov), iface);

free(pfxs);
free(routes);
Expand Down Expand Up @@ -743,7 +762,7 @@ static void forward_router_solicitation(const struct interface *iface)
all_routers.sin6_scope_id = iface->ifindex;

syslog(LOG_NOTICE, "Sending RS to %s", iface->name);
odhcpd_send(router_event.uloop.fd, &all_routers, &iov, 1, iface);
odhcpd_send(iface->router_event.uloop.fd, &all_routers, &iov, 1, iface);
}


Expand Down Expand Up @@ -813,6 +832,6 @@ static void forward_router_advertisement(const struct interface *iface, uint8_t

syslog(LOG_NOTICE, "Forward a RA on %s", c->name);

odhcpd_send(router_event.uloop.fd, &all_nodes, &iov, 1, c);
odhcpd_send(c->router_event.uloop.fd, &all_nodes, &iov, 1, c);
}
}

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