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Factor out Ethernet and socket sending function to avoid a big if-else

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in send_ip_packet.
This commit is contained in:
david
2009-07-03 18:52:54 +00:00
parent 7eb63c1c2d
commit 9cbde2f3a0
1 changed files with 50 additions and 30 deletions
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80
tcpip.cc
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@@ -1373,41 +1373,62 @@ do {
return res;
}
static int send_ip_packet_eth(struct eth_nfo *eth, u8 *packet, unsigned int packetlen);
static int send_ip_packet_sd(int sd, u8 *packet, unsigned int packetlen);
/* Send a pre-built IPv4 packet */
/* Send a pre-built IPv4 packet. Handles fragmentation and whether to send with
an ethernet handle or a socket. */
int send_ip_packet(int sd, struct eth_nfo *eth, u8 *packet, unsigned int packetlen) {
struct sockaddr_in sock;
int res;
struct ip *ip = (struct ip *) packet;
struct tcp_hdr *tcp = NULL;
struct udp_hdr *udp;
u8 *eth_frame = NULL;
eth_t *ethsd;
bool ethsd_opened = false;
int res;
assert(packet);
assert( (int) packetlen > 0);
assert((int) packetlen > 0);
// fragmentation requested && packet is bigger than MTU
if (o.fragscan && ( packetlen - ip->ip_hl * 4 > (unsigned int) o.fragscan ))
return send_frag_ip_packet(sd, eth, packet, packetlen, o.fragscan);
if (o.fragscan && (packetlen - ip->ip_hl * 4 > (unsigned int) o.fragscan))
return send_frag_ip_packet(sd, eth, packet, packetlen, o.fragscan);
if (eth) {
eth_frame = (u8 *) safe_malloc(14 + packetlen);
memcpy(eth_frame + 14, packet, packetlen);
eth_pack_hdr(eth_frame, eth->dstmac, eth->srcmac, ETH_TYPE_IP);
if (!eth->ethsd) {
ethsd = eth_open_cached(eth->devname);
if (!ethsd)
fatal("%s: Failed to open ethernet device (%s)", __func__, eth->devname);
ethsd_opened = true;
} else ethsd = eth->ethsd;
res = eth_send(ethsd, eth_frame, 14 + packetlen);
PacketTrace::trace(PacketTrace::SENT, packet, packetlen);
/* No need to close ethsd due to caching */
free(eth_frame);
eth_frame = NULL;
return res;
if (eth)
res = send_ip_packet_eth(eth, packet, packetlen);
else
res = send_ip_packet_sd(sd, packet, packetlen);
PacketTrace::trace(PacketTrace::SENT, packet, packetlen);
return res;
}
/* Send an IP packet over an ethernet handle. */
static int send_ip_packet_eth(struct eth_nfo *eth, u8 *packet, unsigned int packetlen) {
eth_t *ethsd;
u8 *eth_frame;
int res;
eth_frame = (u8 *) safe_malloc(14 + packetlen);
memcpy(eth_frame + 14, packet, packetlen);
eth_pack_hdr(eth_frame, eth->dstmac, eth->srcmac, ETH_TYPE_IP);
if (!eth->ethsd) {
ethsd = eth_open_cached(eth->devname);
if (!ethsd)
fatal("%s: Failed to open ethernet device (%s)", __func__, eth->devname);
} else {
ethsd = eth->ethsd;
}
res = eth_send(ethsd, eth_frame, 14 + packetlen);
/* No need to close ethsd due to caching */
free(eth_frame);
return res;
}
/* Send an IP packet over a raw socket. */
static int send_ip_packet_sd(int sd, u8 *packet, unsigned int packetlen) {
struct sockaddr_in sock;
struct ip *ip = (struct ip *) packet;
struct tcp_hdr *tcp;
struct udp_hdr *udp;
int res;
assert(sd >= 0);
memset(&sock, 0, sizeof(sock));
@@ -1415,6 +1436,7 @@ int send_ip_packet(int sd, struct eth_nfo *eth, u8 *packet, unsigned int packetl
#if HAVE_SOCKADDR_SA_LEN
sock.sin_len = sizeof(sock);
#endif
/* It is bogus that I need the address and port info when sending a RAW IP
packet, but it doesn't seem to work w/o them */
if (packetlen >= 20) {
@@ -1439,7 +1461,7 @@ int send_ip_packet(int sd, struct eth_nfo *eth, u8 *packet, unsigned int packetl
#endif
res = Sendto("send_ip_packet", sd, packet, packetlen, 0,
(struct sockaddr *)&sock, (int)sizeof(struct sockaddr_in));
(struct sockaddr *) &sock, (int) sizeof(struct sockaddr_in));
/* Undo the byte order switching. */
#if FREEBSD || BSDI || NETBSD || DEC || MACOSX
@@ -1447,8 +1469,6 @@ int send_ip_packet(int sd, struct eth_nfo *eth, u8 *packet, unsigned int packetl
ip->ip_off = htons(ip->ip_off);
#endif
PacketTrace::trace(PacketTrace::SENT, packet, packetlen);
return res;
}