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1.1 root 1: /*
2: * Copyright (c) 1995 Danny Gasparovski.
3: *
4: * Please read the file COPYRIGHT for the
5: * terms and conditions of the copyright.
6: */
7:
8: #include <slirp.h>
9:
10: int if_queued = 0; /* Number of packets queued so far */
11:
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 */
15:
16: #define ifs_init(ifm) ((ifm)->ifs_next = (ifm)->ifs_prev = (ifm))
17:
18: void
19: ifs_insque(ifm, ifmhead)
20: struct mbuf *ifm, *ifmhead;
21: {
22: ifm->ifs_next = ifmhead->ifs_next;
23: ifmhead->ifs_next = ifm;
24: ifm->ifs_prev = ifmhead;
25: ifm->ifs_next->ifs_prev = ifm;
26: }
27:
28: void
29: ifs_remque(ifm)
30: struct mbuf *ifm;
31: {
32: ifm->ifs_prev->ifs_next = ifm->ifs_next;
33: ifm->ifs_next->ifs_prev = ifm->ifs_prev;
34: }
35:
36: void
37: if_init()
38: {
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);
42: next_m = &if_batchq;
43: }
44:
45: #if 0
46: /*
47: * This shouldn't be needed since the modem is blocking and
48: * we don't expect any signals, but what the hell..
49: */
50: inline int
51: writen(fd, bptr, n)
52: int fd;
53: char *bptr;
54: int n;
55: {
56: int ret;
57: int total;
1.1.1.3 ! root 58:
1.1 root 59: /* This should succeed most of the time */
60: ret = send(fd, bptr, n,0);
61: if (ret == n || ret <= 0)
62: return ret;
1.1.1.3 ! root 63:
1.1 root 64: /* Didn't write everything, go into the loop */
65: total = ret;
66: while (n > total) {
67: ret = send(fd, bptr+total, n-total,0);
68: if (ret <= 0)
69: return ret;
70: total += ret;
71: }
72: return total;
73: }
74:
75: /*
76: * if_input - read() the tty, do "top level" processing (ie: check for any escapes),
77: * and pass onto (*ttyp->if_input)
1.1.1.3 ! root 78: *
1.1 root 79: * XXXXX Any zeros arriving by themselves are NOT placed into the arriving packet.
80: */
81: #define INBUFF_SIZE 2048 /* XXX */
82: void
83: if_input(ttyp)
84: struct ttys *ttyp;
85: {
86: u_char if_inbuff[INBUFF_SIZE];
87: int if_n;
1.1.1.3 ! root 88:
1.1 root 89: DEBUG_CALL("if_input");
90: DEBUG_ARG("ttyp = %lx", (long)ttyp);
1.1.1.3 ! root 91:
1.1 root 92: if_n = recv(ttyp->fd, (char *)if_inbuff, INBUFF_SIZE,0);
1.1.1.3 ! root 93:
1.1 root 94: DEBUG_MISC((dfd, " read %d bytes\n", if_n));
1.1.1.3 ! root 95:
1.1 root 96: if (if_n <= 0) {
97: if (if_n == 0 || (errno != EINTR && errno != EAGAIN)) {
98: if (ttyp->up)
99: link_up--;
100: tty_detached(ttyp, 0);
101: }
102: return;
103: }
104: if (if_n == 1) {
105: if (*if_inbuff == '0') {
106: ttyp->ones = 0;
107: if (++ttyp->zeros >= 5)
108: slirp_exit(0);
109: return;
110: }
111: if (*if_inbuff == '1') {
112: ttyp->zeros = 0;
113: if (++ttyp->ones >= 5)
114: tty_detached(ttyp, 0);
115: return;
116: }
117: }
118: ttyp->ones = ttyp->zeros = 0;
1.1.1.3 ! root 119:
1.1 root 120: (*ttyp->if_input)(ttyp, if_inbuff, if_n);
121: }
1.1.1.3 ! root 122: #endif
! 123:
1.1 root 124: /*
125: * if_output: Queue packet into an output queue.
1.1.1.3 ! root 126: * There are 2 output queue's, if_fastq and if_batchq.
1.1 root 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
1.1.1.3 ! root 131: * from the next session, etc. Packets on the if_fastq get absolute
1.1 root 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)
136: */
137: void
138: if_output(so, ifm)
139: struct socket *so;
140: struct mbuf *ifm;
141: {
142: struct mbuf *ifq;
143: int on_fastq = 1;
1.1.1.3 ! root 144:
1.1 root 145: DEBUG_CALL("if_output");
146: DEBUG_ARG("so = %lx", (long)so);
147: DEBUG_ARG("ifm = %lx", (long)ifm);
1.1.1.3 ! root 148:
1.1 root 149: /*
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.
153: */
154: if (ifm->m_flags & M_USEDLIST) {
155: remque(ifm);
156: ifm->m_flags &= ~M_USEDLIST;
157: }
1.1.1.3 ! root 158:
1.1 root 159: /*
1.1.1.3 ! root 160: * See if there's already a batchq list for this session.
1.1 root 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?
165: */
166: for (ifq = if_batchq.ifq_prev; ifq != &if_batchq; ifq = ifq->ifq_prev) {
167: if (so == ifq->ifq_so) {
168: /* A match! */
169: ifm->ifq_so = so;
170: ifs_insque(ifm, ifq->ifs_prev);
171: goto diddit;
172: }
173: }
1.1.1.3 ! root 174:
1.1 root 175: /* No match, check which queue to put it on */
176: if (so && (so->so_iptos & IPTOS_LOWDELAY)) {
177: ifq = if_fastq.ifq_prev;
178: on_fastq = 1;
179: /*
180: * Check if this packet is a part of the last
181: * packet's session
182: */
183: if (ifq->ifq_so == so) {
184: ifm->ifq_so = so;
185: ifs_insque(ifm, ifq->ifs_prev);
186: goto diddit;
187: }
188: } else
189: ifq = if_batchq.ifq_prev;
1.1.1.3 ! root 190:
1.1 root 191: /* Create a new doubly linked list for this session */
192: ifm->ifq_so = so;
193: ifs_init(ifm);
194: insque(ifm, ifq);
1.1.1.3 ! root 195:
1.1 root 196: diddit:
197: ++if_queued;
1.1.1.3 ! root 198:
1.1 root 199: if (so) {
200: /* Update *_queued */
201: so->so_queued++;
202: so->so_nqueued++;
203: /*
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..)
209: */
1.1.1.3 ! root 210: if (on_fastq && ((so->so_nqueued >= 6) &&
1.1 root 211: (so->so_nqueued - so->so_queued) >= 3)) {
1.1.1.3 ! root 212:
1.1 root 213: /* Remove from current queue... */
214: remque(ifm->ifs_next);
1.1.1.3 ! root 215:
1.1 root 216: /* ...And insert in the new. That'll teach ya! */
217: insque(ifm->ifs_next, &if_batchq);
218: }
219: }
220:
221: #ifndef FULL_BOLT
222: /*
223: * This prevents us from malloc()ing too many mbufs
224: */
225: if (link_up) {
226: /* if_start will check towrite */
227: if_start();
228: }
229: #endif
230: }
231:
232: /*
233: * Send a packet
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.
243: */
244: void
245: if_start(void)
246: {
247: struct mbuf *ifm, *ifqt;
1.1.1.3 ! root 248:
1.1 root 249: DEBUG_CALL("if_start");
1.1.1.3 ! root 250:
1.1 root 251: if (if_queued == 0)
252: return; /* Nothing to do */
1.1.1.3 ! root 253:
1.1 root 254: again:
255: /* check if we can really output */
256: if (!slirp_can_output())
257: return;
258:
259: /*
260: * See which queue to get next packet from
261: * If there's something in the fastq, select it immediately
262: */
263: if (if_fastq.ifq_next != &if_fastq) {
264: ifm = if_fastq.ifq_next;
265: } else {
266: /* Nothing on fastq, see if next_m is valid */
267: if (next_m != &if_batchq)
268: ifm = next_m;
269: else
270: ifm = if_batchq.ifq_next;
1.1.1.3 ! root 271:
1.1 root 272: /* Set which packet to send on next iteration */
273: next_m = ifm->ifq_next;
274: }
275: /* Remove it from the queue */
276: ifqt = ifm->ifq_prev;
277: remque(ifm);
278: --if_queued;
1.1.1.3 ! root 279:
1.1 root 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);
283: ifs_remque(ifm);
284: }
1.1.1.3 ! root 285:
1.1 root 286: /* Update so_queued */
287: if (ifm->ifq_so) {
288: if (--ifm->ifq_so->so_queued == 0)
289: /* If there's no more queued, reset nqueued */
290: ifm->ifq_so->so_nqueued = 0;
291: }
1.1.1.3 ! root 292:
1.1 root 293: /* Encapsulate the packet for sending */
294: if_encap(ifm->m_data, ifm->m_len);
295:
296: m_free(ifm);
297:
298: if (if_queued)
299: goto again;
300: }
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