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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: #define ifs_init(ifm) ((ifm)->ifs_next = (ifm)->ifs_prev = (ifm))
11:
1.1.1.4 root 12: static void
13: ifs_insque(struct mbuf *ifm, struct mbuf *ifmhead)
1.1 root 14: {
15: ifm->ifs_next = ifmhead->ifs_next;
16: ifmhead->ifs_next = ifm;
17: ifm->ifs_prev = ifmhead;
18: ifm->ifs_next->ifs_prev = ifm;
19: }
20:
1.1.1.4 root 21: static void
22: ifs_remque(struct mbuf *ifm)
1.1 root 23: {
24: ifm->ifs_prev->ifs_next = ifm->ifs_next;
25: ifm->ifs_next->ifs_prev = ifm->ifs_prev;
26: }
27:
28: void
1.1.1.5 ! root 29: if_init(Slirp *slirp)
1.1 root 30: {
1.1.1.5 ! root 31: slirp->if_fastq.ifq_next = slirp->if_fastq.ifq_prev = &slirp->if_fastq;
! 32: slirp->if_batchq.ifq_next = slirp->if_batchq.ifq_prev = &slirp->if_batchq;
! 33: slirp->next_m = &slirp->if_batchq;
1.1 root 34: }
35:
36: /*
37: * if_output: Queue packet into an output queue.
1.1.1.3 root 38: * There are 2 output queue's, if_fastq and if_batchq.
1.1 root 39: * Each output queue is a doubly linked list of double linked lists
40: * of mbufs, each list belonging to one "session" (socket). This
41: * way, we can output packets fairly by sending one packet from each
42: * session, instead of all the packets from one session, then all packets
1.1.1.3 root 43: * from the next session, etc. Packets on the if_fastq get absolute
1.1 root 44: * priority, but if one session hogs the link, it gets "downgraded"
45: * to the batchq until it runs out of packets, then it'll return
46: * to the fastq (eg. if the user does an ls -alR in a telnet session,
47: * it'll temporarily get downgraded to the batchq)
48: */
49: void
1.1.1.5 ! root 50: if_output(struct socket *so, struct mbuf *ifm)
1.1 root 51: {
1.1.1.5 ! root 52: Slirp *slirp = ifm->slirp;
1.1 root 53: struct mbuf *ifq;
54: int on_fastq = 1;
1.1.1.3 root 55:
1.1 root 56: DEBUG_CALL("if_output");
57: DEBUG_ARG("so = %lx", (long)so);
58: DEBUG_ARG("ifm = %lx", (long)ifm);
1.1.1.3 root 59:
1.1 root 60: /*
61: * First remove the mbuf from m_usedlist,
62: * since we're gonna use m_next and m_prev ourselves
63: * XXX Shouldn't need this, gotta change dtom() etc.
64: */
65: if (ifm->m_flags & M_USEDLIST) {
66: remque(ifm);
67: ifm->m_flags &= ~M_USEDLIST;
68: }
1.1.1.3 root 69:
1.1 root 70: /*
1.1.1.3 root 71: * See if there's already a batchq list for this session.
1.1 root 72: * This can include an interactive session, which should go on fastq,
73: * but gets too greedy... hence it'll be downgraded from fastq to batchq.
74: * We mustn't put this packet back on the fastq (or we'll send it out of order)
75: * XXX add cache here?
76: */
1.1.1.5 ! root 77: for (ifq = slirp->if_batchq.ifq_prev; ifq != &slirp->if_batchq;
! 78: ifq = ifq->ifq_prev) {
1.1 root 79: if (so == ifq->ifq_so) {
80: /* A match! */
81: ifm->ifq_so = so;
82: ifs_insque(ifm, ifq->ifs_prev);
83: goto diddit;
84: }
85: }
1.1.1.3 root 86:
1.1 root 87: /* No match, check which queue to put it on */
88: if (so && (so->so_iptos & IPTOS_LOWDELAY)) {
1.1.1.5 ! root 89: ifq = slirp->if_fastq.ifq_prev;
1.1 root 90: on_fastq = 1;
91: /*
92: * Check if this packet is a part of the last
93: * packet's session
94: */
95: if (ifq->ifq_so == so) {
96: ifm->ifq_so = so;
97: ifs_insque(ifm, ifq->ifs_prev);
98: goto diddit;
99: }
100: } else
1.1.1.5 ! root 101: ifq = slirp->if_batchq.ifq_prev;
1.1.1.3 root 102:
1.1 root 103: /* Create a new doubly linked list for this session */
104: ifm->ifq_so = so;
105: ifs_init(ifm);
106: insque(ifm, ifq);
1.1.1.3 root 107:
1.1 root 108: diddit:
1.1.1.5 ! root 109: slirp->if_queued++;
1.1.1.3 root 110:
1.1 root 111: if (so) {
112: /* Update *_queued */
113: so->so_queued++;
114: so->so_nqueued++;
115: /*
116: * Check if the interactive session should be downgraded to
117: * the batchq. A session is downgraded if it has queued 6
118: * packets without pausing, and at least 3 of those packets
119: * have been sent over the link
120: * (XXX These are arbitrary numbers, probably not optimal..)
121: */
1.1.1.3 root 122: if (on_fastq && ((so->so_nqueued >= 6) &&
1.1 root 123: (so->so_nqueued - so->so_queued) >= 3)) {
1.1.1.3 root 124:
1.1 root 125: /* Remove from current queue... */
126: remque(ifm->ifs_next);
1.1.1.3 root 127:
1.1 root 128: /* ...And insert in the new. That'll teach ya! */
1.1.1.5 ! root 129: insque(ifm->ifs_next, &slirp->if_batchq);
1.1 root 130: }
131: }
132:
133: #ifndef FULL_BOLT
134: /*
135: * This prevents us from malloc()ing too many mbufs
136: */
1.1.1.5 ! root 137: if_start(ifm->slirp);
1.1 root 138: #endif
139: }
140:
141: /*
142: * Send a packet
143: * We choose a packet based on it's position in the output queues;
144: * If there are packets on the fastq, they are sent FIFO, before
145: * everything else. Otherwise we choose the first packet from the
146: * batchq and send it. the next packet chosen will be from the session
147: * after this one, then the session after that one, and so on.. So,
148: * for example, if there are 3 ftp session's fighting for bandwidth,
149: * one packet will be sent from the first session, then one packet
150: * from the second session, then one packet from the third, then back
151: * to the first, etc. etc.
152: */
153: void
1.1.1.5 ! root 154: if_start(Slirp *slirp)
1.1 root 155: {
156: struct mbuf *ifm, *ifqt;
1.1.1.3 root 157:
1.1 root 158: DEBUG_CALL("if_start");
1.1.1.3 root 159:
1.1.1.5 ! root 160: if (slirp->if_queued == 0)
1.1 root 161: return; /* Nothing to do */
1.1.1.3 root 162:
1.1 root 163: again:
164: /* check if we can really output */
1.1.1.5 ! root 165: if (!slirp_can_output(slirp->opaque))
1.1 root 166: return;
167:
168: /*
169: * See which queue to get next packet from
170: * If there's something in the fastq, select it immediately
171: */
1.1.1.5 ! root 172: if (slirp->if_fastq.ifq_next != &slirp->if_fastq) {
! 173: ifm = slirp->if_fastq.ifq_next;
1.1 root 174: } else {
175: /* Nothing on fastq, see if next_m is valid */
1.1.1.5 ! root 176: if (slirp->next_m != &slirp->if_batchq)
! 177: ifm = slirp->next_m;
1.1 root 178: else
1.1.1.5 ! root 179: ifm = slirp->if_batchq.ifq_next;
1.1.1.3 root 180:
1.1 root 181: /* Set which packet to send on next iteration */
1.1.1.5 ! root 182: slirp->next_m = ifm->ifq_next;
1.1 root 183: }
184: /* Remove it from the queue */
185: ifqt = ifm->ifq_prev;
186: remque(ifm);
1.1.1.5 ! root 187: slirp->if_queued--;
1.1.1.3 root 188:
1.1 root 189: /* If there are more packets for this session, re-queue them */
190: if (ifm->ifs_next != /* ifm->ifs_prev != */ ifm) {
191: insque(ifm->ifs_next, ifqt);
192: ifs_remque(ifm);
193: }
1.1.1.3 root 194:
1.1 root 195: /* Update so_queued */
196: if (ifm->ifq_so) {
197: if (--ifm->ifq_so->so_queued == 0)
198: /* If there's no more queued, reset nqueued */
199: ifm->ifq_so->so_nqueued = 0;
200: }
1.1.1.3 root 201:
1.1 root 202: /* Encapsulate the packet for sending */
1.1.1.5 ! root 203: if_encap(slirp, (uint8_t *)ifm->m_data, ifm->m_len);
1.1 root 204:
205: m_free(ifm);
206:
1.1.1.5 ! root 207: if (slirp->if_queued)
1.1 root 208: goto again;
209: }
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