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Merge the recv_packet_v[46] functions into one.
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This reduces some code duplication and makes it easier to see the
difference between the IPv4 and IPv6 raw sockets API.

tweak + ok claudio@, ok benno@
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@rwestphal
rwestphal committed Sep 2, 2016
1 parent 54fe48e commit 6a41179
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Showing 5 changed files with 109 additions and 152 deletions.
2 changes: 2 additions & 0 deletions eigrpd.h
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Original file line number Diff line number Diff line change
Expand Up @@ -436,6 +436,7 @@ struct ctl_stats {
};

#define min(x,y) ((x) <= (y) ? (x) : (y))
#define max(x,y) ((x) > (y) ? (x) : (y))

/* parse.y */
struct eigrpd_conf *parse_config(char *);
Expand Down Expand Up @@ -480,6 +481,7 @@ void embedscope(struct sockaddr_in6 *);
void recoverscope(struct sockaddr_in6 *);
void addscope(struct sockaddr_in6 *, uint32_t);
void clearscope(struct in6_addr *);
void sa2addr(struct sockaddr *, int *, union eigrpd_addr *);

/* eigrpd.c */
int main_imsg_compose_eigrpe(int, pid_t, void *, uint16_t);
Expand Down
4 changes: 2 additions & 2 deletions eigrpe.c
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Original file line number Diff line number Diff line change
Expand Up @@ -159,11 +159,11 @@ eigrpe(int debug, int verbose, char *sockname)
event_add(&iev_main->ev, NULL);

event_set(&ev4, global.eigrp_socket_v4, EV_READ|EV_PERSIST,
recv_packet_v4, econf);
recv_packet, econf);
event_add(&ev4, NULL);

event_set(&ev6, global.eigrp_socket_v6, EV_READ|EV_PERSIST,
recv_packet_v6, econf);
recv_packet, econf);
event_add(&ev6, NULL);

/* listen on eigrpd control socket */
Expand Down
3 changes: 1 addition & 2 deletions eigrpe.h
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Original file line number Diff line number Diff line change
Expand Up @@ -157,8 +157,7 @@ int gen_eigrp_hdr(struct ibuf *, uint16_t, uint8_t, uint32_t,
uint16_t);
int send_packet(struct eigrp_iface *, struct nbr *, uint32_t,
struct ibuf *);
void recv_packet_v4(int, short, void *);
void recv_packet_v6(int, short, void *);
void recv_packet(int, short, void *);

/* tlv.c */
int gen_parameter_tlv(struct ibuf *, struct eigrp_iface *,
Expand Down
231 changes: 83 additions & 148 deletions packet.c
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Original file line number Diff line number Diff line change
Expand Up @@ -34,7 +34,6 @@

extern struct eigrpd_conf *econf;

int ip_hdr_sanity_check(const struct ip *, uint16_t);
int eigrp_hdr_sanity_check(int, union eigrpd_addr *,
struct eigrp_hdr *, uint16_t, const struct iface *);
struct iface *find_iface(unsigned int, int, union eigrpd_addr *);
Expand Down Expand Up @@ -305,7 +304,7 @@ recv_packet_nbr(struct nbr *nbr, struct eigrp_hdr *eigrp_hdr,
}

static void
recv_packet(int af, union eigrpd_addr *src, union eigrpd_addr *dest,
recv_packet_eigrp(int af, union eigrpd_addr *src, union eigrpd_addr *dest,
struct iface *iface, struct eigrp_hdr *eigrp_hdr, char *buf, uint16_t len)
{
struct eigrp_iface *ei;
Expand Down Expand Up @@ -377,7 +376,7 @@ recv_packet(int af, union eigrpd_addr *src, union eigrpd_addr *dest,
if (tlv_decode_route(af, &tlv, buf, &ri) < 0)
goto error;
if ((re = calloc(1, sizeof(*re))) == NULL)
fatal("recv_packet");
fatal("recv_packet_eigrp");
re->rinfo = ri;
TAILQ_INSERT_TAIL(&rinfo_list, re, entry);
break;
Expand Down Expand Up @@ -459,25 +458,27 @@ recv_packet(int af, union eigrpd_addr *src, union eigrpd_addr *dest,
seq_addr_list_clr(&seq_addr_list);
}

#define CMSG_MAXLEN max(sizeof(struct sockaddr_dl), sizeof(struct in6_pktinfo))
void
recv_packet_v4(int fd, short event, void *bula)
recv_packet(int fd, short event, void *bula)
{
union {
struct cmsghdr hdr;
char buf[CMSG_SPACE(sizeof(struct sockaddr_dl))];
char buf[CMSG_SPACE(CMSG_MAXLEN)];
} cmsgbuf;
struct msghdr msg;
struct sockaddr_storage from;
struct iovec iov;
struct ip ip_hdr;
struct eigrp_hdr *eigrp_hdr;
struct iface *iface;
char *buf;
struct cmsghdr *cmsg;
ssize_t r;
uint16_t len;
int l;
unsigned int ifindex = 0;
int af;
union eigrpd_addr src, dest;
unsigned int ifindex = 0;
struct iface *iface;
struct eigrp_hdr *eigrp_hdr;

if (event != EV_READ)
return;
Expand All @@ -486,6 +487,8 @@ recv_packet_v4(int fd, short event, void *bula)
memset(&msg, 0, sizeof(msg));
iov.iov_base = buf = pkt_ptr;
iov.iov_len = READ_BUF_SIZE;
msg.msg_name = &from;
msg.msg_namelen = sizeof(from);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = &cmsgbuf.buf;
Expand All @@ -497,109 +500,24 @@ recv_packet_v4(int fd, short event, void *bula)
strerror(errno));
return;
}
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == IPPROTO_IP &&
cmsg->cmsg_type == IP_RECVIF) {
ifindex = ((struct sockaddr_dl *)
CMSG_DATA(cmsg))->sdl_index;
break;
}
}

len = (uint16_t)r;

/* IP header sanity checks */
if (len < sizeof(ip_hdr)) {
log_debug("%s: bad packet size", __func__);
return;
}
memcpy(&ip_hdr, buf, sizeof(ip_hdr));
if ((l = ip_hdr_sanity_check(&ip_hdr, len)) == -1)
return;
buf += l;
len -= l;

src.v4 = ip_hdr.ip_src;
dest.v4 = ip_hdr.ip_dst;

/* find a matching interface */
if ((iface = find_iface(ifindex, AF_INET, &src)) == NULL)
return;

/*
* Packet needs to be sent to AllEIGRPRouters_v4 or to one
* of the interface addresses.
*/
if (ip_hdr.ip_dst.s_addr != global.mcast_addr_v4.s_addr) {
struct if_addr *if_addr;
int found = 0;

TAILQ_FOREACH(if_addr, &iface->addr_list, entry)
if (if_addr->af == AF_INET &&
ip_hdr.ip_dst.s_addr == if_addr->addr.v4.s_addr) {
found = 1;
break;
}
if (found == 0) {
log_debug("%s: packet sent to wrong address %s, "
"interface %s", __func__, inet_ntoa(ip_hdr.ip_dst),
iface->name);
return;
}
}

if (len < sizeof(*eigrp_hdr)) {
log_debug("%s: bad packet size", __func__);
sa2addr((struct sockaddr *)&from, &af, &src);
if (bad_addr(af, &src)) {
log_debug("%s: invalid source address: %s", __func__,
log_addr(af, &src));
return;
}
eigrp_hdr = (struct eigrp_hdr *)buf;

recv_packet(AF_INET, &src, &dest, iface, eigrp_hdr, buf, len);
}

void
recv_packet_v6(int fd, short event, void *bula)
{
union {
struct cmsghdr hdr;
char buf[CMSG_SPACE(sizeof(struct in6_pktinfo))];
} cmsgbuf;
struct msghdr msg;
struct iovec iov;
struct sockaddr_in6 sin6;
struct eigrp_hdr *eigrp_hdr;
struct iface *iface;
char *buf;
struct cmsghdr *cmsg;
ssize_t r;
uint16_t len;
unsigned int ifindex = 0;
union eigrpd_addr src, dest;

if (event != EV_READ)
return;

/* setup buffer */
memset(&msg, 0, sizeof(msg));
iov.iov_base = buf = pkt_ptr;
iov.iov_len = READ_BUF_SIZE;
msg.msg_name = &sin6;
msg.msg_namelen = sizeof(sin6);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = &cmsgbuf.buf;
msg.msg_controllen = sizeof(cmsgbuf.buf);

if ((r = recvmsg(fd, &msg, 0)) == -1) {
if (errno != EAGAIN && errno != EINTR)
log_debug("%s: read error: %s", __func__,
strerror(errno));
return;
}
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == IPPROTO_IPV6 &&
if (af == AF_INET && cmsg->cmsg_level == IPPROTO_IP &&
cmsg->cmsg_type == IP_RECVIF) {
ifindex = ((struct sockaddr_dl *)
CMSG_DATA(cmsg))->sdl_index;
break;
}
if (af == AF_INET6 && cmsg->cmsg_level == IPPROTO_IPV6 &&
cmsg->cmsg_type == IPV6_PKTINFO) {
ifindex = ((struct in6_pktinfo *)
CMSG_DATA(cmsg))->ipi6_ifindex;
Expand All @@ -608,61 +526,78 @@ recv_packet_v6(int fd, short event, void *bula)
break;
}
}
src.v6 = sin6.sin6_addr;

/* validate source address */
if (bad_addr_v6(&src.v6)) {
log_debug("%s: invalid source address: %s", __func__,
log_addr(AF_INET, &src));
return;
}

/* find a matching interface */
if ((iface = find_iface(ifindex, AF_INET6, &src)) == NULL)
if ((iface = find_iface(ifindex, af, &src)) == NULL)
return;

/*
* Packet needs to be sent to AllEIGRPRouters_v6 or to the
* link local address of the interface.
*/
if (!IN6_ARE_ADDR_EQUAL(&dest.v6, &global.mcast_addr_v6) &&
!IN6_ARE_ADDR_EQUAL(&dest.v6, &iface->linklocal)) {
log_debug("%s: packet sent to wrong address %s, interface %s",
__func__, log_in6addr(&dest.v6), iface->name);
return;
/* the IPv4 raw sockets API gives us direct access to the IP header */
if (af == AF_INET) {
if (len < sizeof(ip_hdr)) {
log_debug("%s: bad packet size", __func__);
return;
}
memcpy(&ip_hdr, buf, sizeof(ip_hdr));
if (ntohs(ip_hdr.ip_len) != len) {
log_debug("%s: invalid IP packet length %u", __func__,
ntohs(ip_hdr.ip_len));
return;
}
buf += ip_hdr.ip_hl << 2;
len -= ip_hdr.ip_hl << 2;
dest.v4 = ip_hdr.ip_dst;
}

/* validate destination address */
switch (af) {
case AF_INET:
/*
* Packet needs to be sent to 224.0.0.10 or to one of the
* interface addresses.
*/
if (dest.v4.s_addr != global.mcast_addr_v4.s_addr) {
struct if_addr *if_addr;
int found = 0;

TAILQ_FOREACH(if_addr, &iface->addr_list, entry)
if (if_addr->af == AF_INET &&
dest.v4.s_addr == if_addr->addr.v4.s_addr) {
found = 1;
break;
}
if (found == 0) {
log_debug("%s: packet sent to wrong address "
"%s, interface %s", __func__,
inet_ntoa(dest.v4), iface->name);
return;
}
}
break;
case AF_INET6:
/*
* Packet needs to be sent to ff02::a or to the link local
* address of the interface.
*/
if (!IN6_ARE_ADDR_EQUAL(&dest.v6, &global.mcast_addr_v6) &&
!IN6_ARE_ADDR_EQUAL(&dest.v6, &iface->linklocal)) {
log_debug("%s: packet sent to wrong address %s, "
"interface %s", __func__, log_in6addr(&dest.v6),
iface->name);
return;
}
break;
default:
fatalx("recv_packet: unknown af");
break;
}

len = (uint16_t)r;
if (len < sizeof(*eigrp_hdr)) {
log_debug("%s: bad packet size", __func__);
return;
}
eigrp_hdr = (struct eigrp_hdr *)buf;

recv_packet(AF_INET6, &src, &dest, iface, eigrp_hdr, buf, len);
}

int
ip_hdr_sanity_check(const struct ip *ip_hdr, uint16_t len)
{
if (ntohs(ip_hdr->ip_len) != len) {
log_debug("%s: invalid IP packet length %u", __func__,
ntohs(ip_hdr->ip_len));
return (-1);
}

/* validate source address */
if (bad_addr_v4(ip_hdr->ip_src)) {
log_debug("%s: invalid source address: %s", __func__,
inet_ntoa(ip_hdr->ip_src));
return (-1);
}

if (ip_hdr->ip_p != IPPROTO_EIGRP)
/* this is enforced by the socket itself */
fatalx("ip_hdr_sanity_check: invalid IP proto");

return (ip_hdr->ip_hl << 2);
recv_packet_eigrp(af, &src, &dest, iface, eigrp_hdr, buf, len);
}

int
Expand Down
21 changes: 21 additions & 0 deletions util.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -306,3 +306,24 @@ clearscope(struct in6_addr *in6)
in6->s6_addr[3] = 0;
}
}

void
sa2addr(struct sockaddr *sa, int *af, union eigrpd_addr *addr)
{
struct sockaddr_in *sa_in = (struct sockaddr_in *)sa;
struct sockaddr_in6 *sa_in6 = (struct sockaddr_in6 *)sa;

memset(addr, 0, sizeof(*addr));
switch (sa->sa_family) {
case AF_INET:
*af = AF_INET;
addr->v4 = sa_in->sin_addr;
break;
case AF_INET6:
*af = AF_INET6;
addr->v6 = sa_in6->sin6_addr;
break;
default:
fatalx("sa2addr: unknown af");
}
}

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