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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:
1.1.1.4 ! root 18: static void
! 19: ifs_insque(struct mbuf *ifm, struct mbuf *ifmhead)
1.1 root 20: {
21: ifm->ifs_next = ifmhead->ifs_next;
22: ifmhead->ifs_next = ifm;
23: ifm->ifs_prev = ifmhead;
24: ifm->ifs_next->ifs_prev = ifm;
25: }
26:
1.1.1.4 ! root 27: static void
! 28: ifs_remque(struct mbuf *ifm)
1.1 root 29: {
30: ifm->ifs_prev->ifs_next = ifm->ifs_next;
31: ifm->ifs_next->ifs_prev = ifm->ifs_prev;
32: }
33:
34: void
35: if_init()
36: {
37: if_fastq.ifq_next = if_fastq.ifq_prev = &if_fastq;
38: if_batchq.ifq_next = if_batchq.ifq_prev = &if_batchq;
39: // sl_compress_init(&comp_s);
40: next_m = &if_batchq;
41: }
42:
43: #if 0
44: /*
45: * This shouldn't be needed since the modem is blocking and
46: * we don't expect any signals, but what the hell..
47: */
48: inline int
49: writen(fd, bptr, n)
50: int fd;
51: char *bptr;
52: int n;
53: {
54: int ret;
55: int total;
1.1.1.3 root 56:
1.1 root 57: /* This should succeed most of the time */
58: ret = send(fd, bptr, n,0);
59: if (ret == n || ret <= 0)
60: return ret;
1.1.1.3 root 61:
1.1 root 62: /* Didn't write everything, go into the loop */
63: total = ret;
64: while (n > total) {
65: ret = send(fd, bptr+total, n-total,0);
66: if (ret <= 0)
67: return ret;
68: total += ret;
69: }
70: return total;
71: }
72:
73: /*
74: * if_input - read() the tty, do "top level" processing (ie: check for any escapes),
75: * and pass onto (*ttyp->if_input)
1.1.1.3 root 76: *
1.1 root 77: * XXXXX Any zeros arriving by themselves are NOT placed into the arriving packet.
78: */
79: #define INBUFF_SIZE 2048 /* XXX */
80: void
81: if_input(ttyp)
82: struct ttys *ttyp;
83: {
84: u_char if_inbuff[INBUFF_SIZE];
85: int if_n;
1.1.1.3 root 86:
1.1 root 87: DEBUG_CALL("if_input");
88: DEBUG_ARG("ttyp = %lx", (long)ttyp);
1.1.1.3 root 89:
1.1 root 90: if_n = recv(ttyp->fd, (char *)if_inbuff, INBUFF_SIZE,0);
1.1.1.3 root 91:
1.1 root 92: DEBUG_MISC((dfd, " read %d bytes\n", if_n));
1.1.1.3 root 93:
1.1 root 94: if (if_n <= 0) {
95: if (if_n == 0 || (errno != EINTR && errno != EAGAIN)) {
96: if (ttyp->up)
97: link_up--;
98: tty_detached(ttyp, 0);
99: }
100: return;
101: }
102: if (if_n == 1) {
103: if (*if_inbuff == '0') {
104: ttyp->ones = 0;
105: if (++ttyp->zeros >= 5)
106: slirp_exit(0);
107: return;
108: }
109: if (*if_inbuff == '1') {
110: ttyp->zeros = 0;
111: if (++ttyp->ones >= 5)
112: tty_detached(ttyp, 0);
113: return;
114: }
115: }
116: ttyp->ones = ttyp->zeros = 0;
1.1.1.3 root 117:
1.1 root 118: (*ttyp->if_input)(ttyp, if_inbuff, if_n);
119: }
1.1.1.3 root 120: #endif
121:
1.1 root 122: /*
123: * if_output: Queue packet into an output queue.
1.1.1.3 root 124: * There are 2 output queue's, if_fastq and if_batchq.
1.1 root 125: * Each output queue is a doubly linked list of double linked lists
126: * of mbufs, each list belonging to one "session" (socket). This
127: * way, we can output packets fairly by sending one packet from each
128: * session, instead of all the packets from one session, then all packets
1.1.1.3 root 129: * from the next session, etc. Packets on the if_fastq get absolute
1.1 root 130: * priority, but if one session hogs the link, it gets "downgraded"
131: * to the batchq until it runs out of packets, then it'll return
132: * to the fastq (eg. if the user does an ls -alR in a telnet session,
133: * it'll temporarily get downgraded to the batchq)
134: */
135: void
136: if_output(so, ifm)
137: struct socket *so;
138: struct mbuf *ifm;
139: {
140: struct mbuf *ifq;
141: int on_fastq = 1;
1.1.1.3 root 142:
1.1 root 143: DEBUG_CALL("if_output");
144: DEBUG_ARG("so = %lx", (long)so);
145: DEBUG_ARG("ifm = %lx", (long)ifm);
1.1.1.3 root 146:
1.1 root 147: /*
148: * First remove the mbuf from m_usedlist,
149: * since we're gonna use m_next and m_prev ourselves
150: * XXX Shouldn't need this, gotta change dtom() etc.
151: */
152: if (ifm->m_flags & M_USEDLIST) {
153: remque(ifm);
154: ifm->m_flags &= ~M_USEDLIST;
155: }
1.1.1.3 root 156:
1.1 root 157: /*
1.1.1.3 root 158: * See if there's already a batchq list for this session.
1.1 root 159: * This can include an interactive session, which should go on fastq,
160: * but gets too greedy... hence it'll be downgraded from fastq to batchq.
161: * We mustn't put this packet back on the fastq (or we'll send it out of order)
162: * XXX add cache here?
163: */
164: for (ifq = if_batchq.ifq_prev; ifq != &if_batchq; ifq = ifq->ifq_prev) {
165: if (so == ifq->ifq_so) {
166: /* A match! */
167: ifm->ifq_so = so;
168: ifs_insque(ifm, ifq->ifs_prev);
169: goto diddit;
170: }
171: }
1.1.1.3 root 172:
1.1 root 173: /* No match, check which queue to put it on */
174: if (so && (so->so_iptos & IPTOS_LOWDELAY)) {
175: ifq = if_fastq.ifq_prev;
176: on_fastq = 1;
177: /*
178: * Check if this packet is a part of the last
179: * packet's session
180: */
181: if (ifq->ifq_so == so) {
182: ifm->ifq_so = so;
183: ifs_insque(ifm, ifq->ifs_prev);
184: goto diddit;
185: }
186: } else
187: ifq = if_batchq.ifq_prev;
1.1.1.3 root 188:
1.1 root 189: /* Create a new doubly linked list for this session */
190: ifm->ifq_so = so;
191: ifs_init(ifm);
192: insque(ifm, ifq);
1.1.1.3 root 193:
1.1 root 194: diddit:
195: ++if_queued;
1.1.1.3 root 196:
1.1 root 197: if (so) {
198: /* Update *_queued */
199: so->so_queued++;
200: so->so_nqueued++;
201: /*
202: * Check if the interactive session should be downgraded to
203: * the batchq. A session is downgraded if it has queued 6
204: * packets without pausing, and at least 3 of those packets
205: * have been sent over the link
206: * (XXX These are arbitrary numbers, probably not optimal..)
207: */
1.1.1.3 root 208: if (on_fastq && ((so->so_nqueued >= 6) &&
1.1 root 209: (so->so_nqueued - so->so_queued) >= 3)) {
1.1.1.3 root 210:
1.1 root 211: /* Remove from current queue... */
212: remque(ifm->ifs_next);
1.1.1.3 root 213:
1.1 root 214: /* ...And insert in the new. That'll teach ya! */
215: insque(ifm->ifs_next, &if_batchq);
216: }
217: }
218:
219: #ifndef FULL_BOLT
220: /*
221: * This prevents us from malloc()ing too many mbufs
222: */
223: if (link_up) {
224: /* if_start will check towrite */
225: if_start();
226: }
227: #endif
228: }
229:
230: /*
231: * Send a packet
232: * We choose a packet based on it's position in the output queues;
233: * If there are packets on the fastq, they are sent FIFO, before
234: * everything else. Otherwise we choose the first packet from the
235: * batchq and send it. the next packet chosen will be from the session
236: * after this one, then the session after that one, and so on.. So,
237: * for example, if there are 3 ftp session's fighting for bandwidth,
238: * one packet will be sent from the first session, then one packet
239: * from the second session, then one packet from the third, then back
240: * to the first, etc. etc.
241: */
242: void
243: if_start(void)
244: {
245: struct mbuf *ifm, *ifqt;
1.1.1.3 root 246:
1.1 root 247: DEBUG_CALL("if_start");
1.1.1.3 root 248:
1.1 root 249: if (if_queued == 0)
250: return; /* Nothing to do */
1.1.1.3 root 251:
1.1 root 252: again:
253: /* check if we can really output */
254: if (!slirp_can_output())
255: return;
256:
257: /*
258: * See which queue to get next packet from
259: * If there's something in the fastq, select it immediately
260: */
261: if (if_fastq.ifq_next != &if_fastq) {
262: ifm = if_fastq.ifq_next;
263: } else {
264: /* Nothing on fastq, see if next_m is valid */
265: if (next_m != &if_batchq)
266: ifm = next_m;
267: else
268: ifm = if_batchq.ifq_next;
1.1.1.3 root 269:
1.1 root 270: /* Set which packet to send on next iteration */
271: next_m = ifm->ifq_next;
272: }
273: /* Remove it from the queue */
274: ifqt = ifm->ifq_prev;
275: remque(ifm);
276: --if_queued;
1.1.1.3 root 277:
1.1 root 278: /* If there are more packets for this session, re-queue them */
279: if (ifm->ifs_next != /* ifm->ifs_prev != */ ifm) {
280: insque(ifm->ifs_next, ifqt);
281: ifs_remque(ifm);
282: }
1.1.1.3 root 283:
1.1 root 284: /* Update so_queued */
285: if (ifm->ifq_so) {
286: if (--ifm->ifq_so->so_queued == 0)
287: /* If there's no more queued, reset nqueued */
288: ifm->ifq_so->so_nqueued = 0;
289: }
1.1.1.3 root 290:
1.1 root 291: /* Encapsulate the packet for sending */
1.1.1.4 ! root 292: if_encap((uint8_t *)ifm->m_data, ifm->m_len);
1.1 root 293:
294: m_free(ifm);
295:
296: if (if_queued)
297: goto again;
298: }
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