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Avoid memmove() for legacy UDP packets.

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This commit is contained in:
Guus Sliepen 2014-12-08 00:44:38 +01:00
parent c2319e90b1
commit 263d990382
2 changed files with 25 additions and 22 deletions
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12
src/net.h
View file

@ -87,12 +87,18 @@ typedef union sockaddr_t {
typedef struct vpn_packet_t { typedef struct vpn_packet_t {
length_t len; /* the actual number of bytes in the `data' field */ length_t len; /* the actual number of bytes in the `data' field */
int priority; /* priority or TOS */ int priority; /* priority or TOS */
node_id_t dstid; /* node ID of the final recipient */ uint32_t seqno; /* 32 bits sequence number (network byte order of course) */
node_id_t srcid; /* node ID of the original sender */
uint8_t seqno[4]; /* 32 bits sequence number (network byte order of course) */
uint8_t data[MAXSIZE]; uint8_t data[MAXSIZE];
} vpn_packet_t; } vpn_packet_t;
typedef struct sptps_packet_t {
length_t len; /* the actual number of bytes in the `data' field */
int priority; /* priority or TOS */
node_id_t dstid; /* node ID of the final recipient */
node_id_t srcid; /* node ID of the original sender */
char data[MAXSIZE];
} sptps_packet_t;
/* Packet types when using SPTPS */ /* Packet types when using SPTPS */
#define PKT_COMPRESSED 1 #define PKT_COMPRESSED 1

35
src/net_packet.c
View file

@ -348,12 +348,12 @@ static void receive_packet(node_t *n, vpn_packet_t *packet) {
static bool try_mac(node_t *n, const vpn_packet_t *inpkt) { static bool try_mac(node_t *n, const vpn_packet_t *inpkt) {
if(n->status.sptps) if(n->status.sptps)
return sptps_verify_datagram(&n->sptps, (char *)&inpkt->seqno, inpkt->len); return sptps_verify_datagram(&n->sptps, ((sptps_packet_t *)inpkt)->data, inpkt->len);
if(!digest_active(n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(n->indigest)) if(!digest_active(n->indigest) || inpkt->len < sizeof inpkt->seqno + digest_length(n->indigest))
return false; return false;
return digest_verify(n->indigest, &inpkt->seqno, inpkt->len - digest_length(n->indigest), (const char *)&inpkt->seqno + inpkt->len - digest_length(n->indigest)); return digest_verify(n->indigest, (const char *)&inpkt->seqno, inpkt->len - digest_length(n->indigest), (const char *)&inpkt->seqno + inpkt->len - digest_length(n->indigest));
} }
static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) { static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
@ -372,7 +372,7 @@ static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
} }
return false; return false;
} }
if(!sptps_receive_data(&n->sptps, (char *)&inpkt->seqno, inpkt->len)) { if(!sptps_receive_data(&n->sptps, ((sptps_packet_t *)&inpkt)->data, inpkt->len)) {
logger(DEBUG_TRAFFIC, LOG_ERR, "Got bad packet from %s (%s)", n->name, n->hostname); logger(DEBUG_TRAFFIC, LOG_ERR, "Got bad packet from %s (%s)", n->name, n->hostname);
return false; return false;
} }
@ -419,9 +419,7 @@ static bool receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
/* Check the sequence number */ /* Check the sequence number */
inpkt->len -= sizeof inpkt->seqno; inpkt->len -= sizeof inpkt->seqno;
uint32_t seqno; uint32_t seqno = ntohl(inpkt->seqno);
memcpy(&seqno, inpkt->seqno, sizeof seqno);
seqno = ntohl(seqno);
if(replaywin) { if(replaywin) {
if(seqno != n->received_seqno + 1) { if(seqno != n->received_seqno + 1) {
@ -699,8 +697,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
/* Add sequence number */ /* Add sequence number */
uint32_t seqno = htonl(++(n->sent_seqno)); inpkt->seqno = htonl(++(n->sent_seqno));
memcpy(inpkt->seqno, &seqno, sizeof inpkt->seqno);
inpkt->len += sizeof inpkt->seqno; inpkt->len += sizeof inpkt->seqno;
/* Encrypt the packet */ /* Encrypt the packet */
@ -709,7 +706,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
outpkt = pkt[nextpkt++]; outpkt = pkt[nextpkt++];
outlen = MAXSIZE; outlen = MAXSIZE;
if(!cipher_encrypt(n->outcipher, inpkt->seqno, inpkt->len, outpkt->seqno, &outlen, true)) { if(!cipher_encrypt(n->outcipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname); logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
goto end; goto end;
} }
@ -721,7 +718,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
/* Add the message authentication code */ /* Add the message authentication code */
if(digest_active(n->outdigest)) { if(digest_active(n->outdigest)) {
if(!digest_create(n->outdigest, inpkt->seqno, inpkt->len, inpkt->seqno + inpkt->len)) { if(!digest_create(n->outdigest, &inpkt->seqno, inpkt->len, &inpkt->seqno + inpkt->len)) {
logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname); logger(DEBUG_TRAFFIC, LOG_ERR, "Error while encrypting packet to %s (%s)", n->name, n->hostname);
goto end; goto end;
} }
@ -749,7 +746,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
} }
#endif #endif
if(sendto(listen_socket[sock].udp.fd, inpkt->seqno, inpkt->len, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) { if(sendto(listen_socket[sock].udp.fd, &inpkt->seqno, inpkt->len, 0, &sa->sa, SALEN(sa->sa)) < 0 && !sockwouldblock(sockerrno)) {
if(sockmsgsize(sockerrno)) { if(sockmsgsize(sockerrno)) {
if(n->maxmtu >= origlen) if(n->maxmtu >= origlen)
n->maxmtu = origlen - 1; n->maxmtu = origlen - 1;
@ -1031,6 +1028,7 @@ static node_t *try_harder(const sockaddr_t *from, const vpn_packet_t *pkt) {
void handle_incoming_vpn_data(void *data, int flags) { void handle_incoming_vpn_data(void *data, int flags) {
listen_socket_t *ls = data; listen_socket_t *ls = data;
vpn_packet_t pkt; vpn_packet_t pkt;
sptps_packet_t *spkt = (sptps_packet_t *)&pkt;
char *hostname; char *hostname;
sockaddr_t from = {{0}}; sockaddr_t from = {{0}};
socklen_t fromlen = sizeof from; socklen_t fromlen = sizeof from;
@ -1038,7 +1036,7 @@ void handle_incoming_vpn_data(void *data, int flags) {
node_t *to = myself; node_t *to = myself;
int len; int len;
len = recvfrom(ls->udp.fd, &pkt.dstid, MAXSIZE, 0, &from.sa, &fromlen); len = recvfrom(ls->udp.fd, &pkt.seqno, MAXSIZE, 0, &from.sa, &fromlen);
if(len <= 0 || len > MAXSIZE) { if(len <= 0 || len > MAXSIZE) {
if(!sockwouldblock(sockerrno)) if(!sockwouldblock(sockerrno))
@ -1051,21 +1049,21 @@ void handle_incoming_vpn_data(void *data, int flags) {
sockaddrunmap(&from); /* Some braindead IPv6 implementations do stupid things. */ sockaddrunmap(&from); /* Some braindead IPv6 implementations do stupid things. */
bool direct = false; bool direct = false;
if(len >= sizeof pkt.dstid + sizeof pkt.srcid) { if(len >= sizeof spkt->dstid + sizeof spkt->srcid) {
n = lookup_node_id(&pkt.srcid); n = lookup_node_id(&spkt->srcid);
if(n) { if(n) {
node_id_t nullid = {}; node_id_t nullid = {};
if(memcmp(&pkt.dstid, &nullid, sizeof nullid) == 0) { if(memcmp(&spkt->dstid, &nullid, sizeof nullid) == 0) {
/* A zero dstid is used to indicate a direct, non-relayed packet. */ /* A zero dstid is used to indicate a direct, non-relayed packet. */
direct = true; direct = true;
} else { } else {
to = lookup_node_id(&pkt.dstid); to = lookup_node_id(&spkt->dstid);
if(!to) { if(!to) {
logger(DEBUG_PROTOCOL, LOG_WARNING, "Received UDP packet presumably sent by %s (%s) but with unknown destination ID", n->name, n->hostname); logger(DEBUG_PROTOCOL, LOG_WARNING, "Received UDP packet presumably sent by %s (%s) but with unknown destination ID", n->name, n->hostname);
return; return;
} }
} }
pkt.len -= sizeof pkt.dstid + sizeof pkt.srcid; pkt.len -= sizeof spkt->dstid + sizeof spkt->srcid;
} }
} }
@ -1078,14 +1076,13 @@ void handle_incoming_vpn_data(void *data, int flags) {
return; return;
} }
send_sptps_data_priv(to, n, 0, pkt.seqno, pkt.len); send_sptps_data_priv(to, n, 0, spkt->data, pkt.len);
return; return;
} }
if(!n) { if(!n) {
/* Most likely an old-style packet without node IDs. */ /* Most likely an old-style packet without node IDs. */
direct = true; direct = true;
memmove(pkt.seqno, &pkt.dstid, sizeof pkt - offsetof(vpn_packet_t, seqno));
n = lookup_node_udp(&from); n = lookup_node_udp(&from);
} }