1 // vim: noet sw=4 ts=4:
3 ==================================================================================
4 Copyright (c) 2020 Nokia
5 Copyright (c) 2020 AT&T Intellectual Property.
7 Licensed under the Apache License, Version 2.0 (the "License");
8 you may not use this file except in compliance with the License.
9 You may obtain a copy of the License at
11 http://www.apache.org/licenses/LICENSE-2.0
13 Unless required by applicable law or agreed to in writing, software
14 distributed under the License is distributed on an "AS IS" BASIS,
15 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 See the License for the specific language governing permissions and
17 limitations under the License.
18 ==================================================================================
23 *-----------------------------------------------------------------------------------
25 * Mnemonic: SIestablish
26 * Abstract:i Prep functions that set up a socket for listening or making a
29 * Author: E. Scott Daniels
31 * Modified: 19 Apr 1995 - To keep returned address of the port.
32 * 08 Mar 2007 - conversion for ipv6.
33 * 12 Oct 2020 - split into connect prep and listen prep
35 *-----------------------------------------------------------------------------------
39 #include "sisetup.h" // include the necessary setup stuff
40 #include "sitransport.h"
42 #include <netinet/tcp.h>
45 #define SO_REUSEPORT 0
49 Prep a socket for "listening."
50 This routine will open a socket and bind an address to it in
51 preparation for listening for connections or inbound UDP
52 datagrams. A file descriptor for the socket is captured and all
53 related information is placed into a transport provider (tp) block.
55 Type is the SI constant UDP_DEVICE or TCP_DEVICE
56 abuf points to the address that is to be bound to the socket.
57 Family is one of the AF_* constants (AF_ANY, AF_INET or AF_INET6)
59 The address should be one of these forms:
60 [::1]:port // v6 localhost device (loop back)
61 localhost:port // v4 or 6 loopback depending on /etc/hosts
62 0.0.0.0:port // any interface
63 addr:port // an address assigned to one of the devices
65 Returns a transport struct which is the main context for the listener.
67 extern struct tp_blk *SIlisten_prep( struct ginfo_blk *gptr, int type, char* abuf, int family ) {
68 struct tp_blk *tptr; // pointer at new tp block
69 int status = SI_OK; // processing status
70 struct sockaddr *addr; // IP address we are requesting
71 int protocol; // protocol for socket call
72 char buf[256]; // buffer to build request address in
76 tptr = (struct tp_blk *) SInew( TP_BLK ); // new transport info block
82 switch( type ) // things specifc to tcp or udp
85 tptr->type = SOCK_DGRAM;
86 protocol = IPPROTO_UDP;
91 tptr->type = SOCK_STREAM;
92 protocol = IPPROTO_TCP;
95 alen = SIgenaddr( abuf, protocol, family, tptr->type, &addr ); // family == 0 for type that suits the address passed in
100 tptr->family = addr->sa_family;
102 if( (tptr->fd = SOCKET( tptr->family, tptr->type, protocol )) >= SI_OK ) {
105 SETSOCKOPT(tptr->fd, SOL_SOCKET, SO_REUSEPORT, (char *)&optval, sizeof( optval) ) ;
108 status = BIND( tptr->fd, (struct sockaddr *) addr, alen );
109 if( status == SI_OK ) {
110 tptr->addr = addr; // save address
112 fprintf( stderr, ">>>>> siestablish: bind failed: fam=%d type=%d pro=%d %s\n", tptr->family, tptr->type, protocol, strerror( errno ) );
116 status = ! SI_OK; // force bad return later
117 fprintf( stderr, ">>>>> siestablish: socket not esablished: fam=%d type=%d pro=%d %s\n", tptr->family, tptr->type, protocol, strerror( errno ) );
120 if( status != SI_OK ) { // socket or bind call failed - clean up stuff
121 fprintf( stderr, ">>>>> siestablish: bad state -- returning nil pointer\n" );
123 SItrash( TP_BLK, tptr ); // free the trasnsport block
124 tptr = NULL; // set to return nothing
132 Look at the address and determine if the connect attempt to this address must
133 use safe_connect() rather than the system connect() call. On linux, a smart
134 connect is needed if the target port is >32K and is even. This makes the assumption
135 that the local port rage floor is 32K; we could read something in /proc, but
136 at this point won't bother. Returns true if we determine that it is best to
139 static int need_smartc( char* abuf ) {
144 if( (tok = strchr( abuf, ':')) != NULL ) {
146 if( v < 32767 || v % 2 != 0 ) {
155 Prep a socket to use to connect to a listener.
156 Establish a transport block and target address in prep to connect.
157 Type is the SI constant UDP_DEVICE or TCP_DEVICE. The abuf pointer
158 should point to either a name:port or IP:port string. Family should
159 be 0 to select the family best suited to the address provided, or
160 any (v4 or v6) if the address is a name. If a perticular type is
161 desired family should be either AF_INET or AF_INET6. Using a
162 family of 0 (AF_ANY) is usually the best choice.
164 extern struct tp_blk *SIconn_prep( struct ginfo_blk *gptr, int type, char *abuf, int family ) {
165 struct tp_blk *tptr; // pointer at new tp block
166 struct sockaddr *addr; // IP address we are requesting
167 int protocol; // protocol for socket call
168 char buf[256]; // buffer to build request address in
172 tptr = (struct tp_blk *) SInew( TP_BLK ); // new transport info block
178 switch( type ) // things specifc to tcp or udp
181 tptr->type = SOCK_DGRAM;
182 protocol = IPPROTO_UDP;
187 tptr->type = SOCK_STREAM;
188 protocol = IPPROTO_TCP;
191 alen = SIgenaddr( abuf, protocol, family, tptr->type, &addr ); // family == 0 for type that suits the address passed in
194 //fprintf( stderr, ">>>>> siconn_prep: error generating an address struct for %s(abuf) %d(proto) %d(type): %s\n",
195 // abuf, protocol, tptr->type, strerror( errno ) );
199 tptr->family = addr->sa_family;
202 if( (tptr->fd = SOCKET( tptr->family, tptr->type, protocol )) >= SI_OK ) {
205 if( gptr->tcp_flags & SI_TF_NODELAY ) {
210 SETSOCKOPT( tptr->fd, SOL_TCP, TCP_NODELAY, (void *)&optval, sizeof( optval) ) ;
212 if( gptr->tcp_flags & SI_TF_FASTACK ) {
217 SETSOCKOPT( tptr->fd, SOL_TCP, TCP_QUICKACK, (void *)&optval, sizeof( optval) ) ;
219 tptr->paddr = addr; // tuck the remote peer address away
220 if( need_smartc( abuf ) ) {
221 tptr->flags |= TPF_SAFEC;
225 SItrash( TP_BLK, tptr ); // free the trasnsport block
226 tptr = NULL; // we'll return nil