2 * Copyright (c) 1995 Danny Gasparovski.
4 * Please read the file COPYRIGHT for the
5 * terms and conditions of the copyright.
10 int if_queued = 0; /* Number of packets queued so far */
12 struct mbuf if_fastq; /* fast queue (for interactive data) */
13 struct mbuf if_batchq; /* queue for non-interactive data */
14 struct mbuf *next_m; /* Pointer to next mbuf to output */
16 #define ifs_init(ifm) ((ifm)->ifs_next = (ifm)->ifs_prev = (ifm))
19 ifs_insque(ifm, ifmhead)
20 struct mbuf *ifm, *ifmhead;
22 ifm->ifs_next = ifmhead->ifs_next;
23 ifmhead->ifs_next = ifm;
24 ifm->ifs_prev = ifmhead;
25 ifm->ifs_next->ifs_prev = ifm;
32 ifm->ifs_prev->ifs_next = ifm->ifs_next;
33 ifm->ifs_next->ifs_prev = ifm->ifs_prev;
39 if_fastq.ifq_next = if_fastq.ifq_prev = &if_fastq;
40 if_batchq.ifq_next = if_batchq.ifq_prev = &if_batchq;
41 // sl_compress_init(&comp_s);
47 * This shouldn't be needed since the modem is blocking and
48 * we don't expect any signals, but what the hell..
59 /* This should succeed most of the time */
60 ret = send(fd, bptr, n,0);
61 if (ret == n || ret <= 0)
64 /* Didn't write everything, go into the loop */
67 ret = send(fd, bptr+total, n-total,0);
76 * if_input - read() the tty, do "top level" processing (ie: check for any escapes),
77 * and pass onto (*ttyp->if_input)
79 * XXXXX Any zeros arriving by themselves are NOT placed into the arriving packet.
81 #define INBUFF_SIZE 2048 /* XXX */
86 u_char if_inbuff[INBUFF_SIZE];
89 DEBUG_CALL("if_input");
90 DEBUG_ARG("ttyp = %lx", (long)ttyp);
92 if_n = recv(ttyp->fd, (char *)if_inbuff, INBUFF_SIZE,0);
94 DEBUG_MISC((dfd, " read %d bytes\n", if_n));
97 if (if_n == 0 || (errno != EINTR && errno != EAGAIN)) {
100 tty_detached(ttyp, 0);
105 if (*if_inbuff == '0') {
107 if (++ttyp->zeros >= 5)
111 if (*if_inbuff == '1') {
113 if (++ttyp->ones >= 5)
114 tty_detached(ttyp, 0);
118 ttyp->ones = ttyp->zeros = 0;
120 (*ttyp->if_input)(ttyp, if_inbuff, if_n);
125 * if_output: Queue packet into an output queue.
126 * There are 2 output queue's, if_fastq and if_batchq.
127 * Each output queue is a doubly linked list of double linked lists
128 * of mbufs, each list belonging to one "session" (socket). This
129 * way, we can output packets fairly by sending one packet from each
130 * session, instead of all the packets from one session, then all packets
131 * from the next session, etc. Packets on the if_fastq get absolute
132 * priority, but if one session hogs the link, it gets "downgraded"
133 * to the batchq until it runs out of packets, then it'll return
134 * to the fastq (eg. if the user does an ls -alR in a telnet session,
135 * it'll temporarily get downgraded to the batchq)
145 DEBUG_CALL("if_output");
146 DEBUG_ARG("so = %lx", (long)so);
147 DEBUG_ARG("ifm = %lx", (long)ifm);
150 * First remove the mbuf from m_usedlist,
151 * since we're gonna use m_next and m_prev ourselves
152 * XXX Shouldn't need this, gotta change dtom() etc.
154 if (ifm->m_flags & M_USEDLIST) {
156 ifm->m_flags &= ~M_USEDLIST;
160 * See if there's already a batchq list for this session.
161 * This can include an interactive session, which should go on fastq,
162 * but gets too greedy... hence it'll be downgraded from fastq to batchq.
163 * We mustn't put this packet back on the fastq (or we'll send it out of order)
164 * XXX add cache here?
166 for (ifq = if_batchq.ifq_prev; ifq != &if_batchq; ifq = ifq->ifq_prev) {
167 if (so == ifq->ifq_so) {
170 ifs_insque(ifm, ifq->ifs_prev);
175 /* No match, check which queue to put it on */
176 if (so && (so->so_iptos & IPTOS_LOWDELAY)) {
177 ifq = if_fastq.ifq_prev;
180 * Check if this packet is a part of the last
183 if (ifq->ifq_so == so) {
185 ifs_insque(ifm, ifq->ifs_prev);
189 ifq = if_batchq.ifq_prev;
191 /* Create a new doubly linked list for this session */
200 /* Update *_queued */
204 * Check if the interactive session should be downgraded to
205 * the batchq. A session is downgraded if it has queued 6
206 * packets without pausing, and at least 3 of those packets
207 * have been sent over the link
208 * (XXX These are arbitrary numbers, probably not optimal..)
210 if (on_fastq && ((so->so_nqueued >= 6) &&
211 (so->so_nqueued - so->so_queued) >= 3)) {
213 /* Remove from current queue... */
214 remque(ifm->ifs_next);
216 /* ...And insert in the new. That'll teach ya! */
217 insque(ifm->ifs_next, &if_batchq);
223 * This prevents us from malloc()ing too many mbufs
226 /* if_start will check towrite */
234 * We choose a packet based on it's position in the output queues;
235 * If there are packets on the fastq, they are sent FIFO, before
236 * everything else. Otherwise we choose the first packet from the
237 * batchq and send it. the next packet chosen will be from the session
238 * after this one, then the session after that one, and so on.. So,
239 * for example, if there are 3 ftp session's fighting for bandwidth,
240 * one packet will be sent from the first session, then one packet
241 * from the second session, then one packet from the third, then back
242 * to the first, etc. etc.
247 struct mbuf *ifm, *ifqt;
249 DEBUG_CALL("if_start");
252 return; /* Nothing to do */
255 /* check if we can really output */
256 if (!slirp_can_output())
260 * See which queue to get next packet from
261 * If there's something in the fastq, select it immediately
263 if (if_fastq.ifq_next != &if_fastq) {
264 ifm = if_fastq.ifq_next;
266 /* Nothing on fastq, see if next_m is valid */
267 if (next_m != &if_batchq)
270 ifm = if_batchq.ifq_next;
272 /* Set which packet to send on next iteration */
273 next_m = ifm->ifq_next;
275 /* Remove it from the queue */
276 ifqt = ifm->ifq_prev;
280 /* If there are more packets for this session, re-queue them */
281 if (ifm->ifs_next != /* ifm->ifs_prev != */ ifm) {
282 insque(ifm->ifs_next, ifqt);
286 /* Update so_queued */
288 if (--ifm->ifq_so->so_queued == 0)
289 /* If there's no more queued, reset nqueued */
290 ifm->ifq_so->so_nqueued = 0;
293 /* Encapsulate the packet for sending */
294 if_encap(ifm->m_data, ifm->m_len);