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1 | f0cbd3ec | bellard | /*
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2 | f0cbd3ec | bellard | * Copyright (c) 1995 Danny Gasparovski.
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3 | f0cbd3ec | bellard | *
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4 | f0cbd3ec | bellard | * Please read the file COPYRIGHT for the
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5 | f0cbd3ec | bellard | * terms and conditions of the copyright.
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6 | f0cbd3ec | bellard | */
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7 | f0cbd3ec | bellard | |
8 | f0cbd3ec | bellard | #include <slirp.h> |
9 | f0cbd3ec | bellard | |
10 | f0cbd3ec | bellard | #define ifs_init(ifm) ((ifm)->ifs_next = (ifm)->ifs_prev = (ifm))
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11 | f0cbd3ec | bellard | |
12 | 674bb261 | blueswir1 | static void |
13 | a5f1b965 | blueswir1 | ifs_insque(struct mbuf *ifm, struct mbuf *ifmhead) |
14 | f0cbd3ec | bellard | { |
15 | f0cbd3ec | bellard | ifm->ifs_next = ifmhead->ifs_next; |
16 | f0cbd3ec | bellard | ifmhead->ifs_next = ifm; |
17 | f0cbd3ec | bellard | ifm->ifs_prev = ifmhead; |
18 | f0cbd3ec | bellard | ifm->ifs_next->ifs_prev = ifm; |
19 | f0cbd3ec | bellard | } |
20 | f0cbd3ec | bellard | |
21 | 674bb261 | blueswir1 | static void |
22 | a5f1b965 | blueswir1 | ifs_remque(struct mbuf *ifm)
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23 | f0cbd3ec | bellard | { |
24 | f0cbd3ec | bellard | ifm->ifs_prev->ifs_next = ifm->ifs_next; |
25 | f0cbd3ec | bellard | ifm->ifs_next->ifs_prev = ifm->ifs_prev; |
26 | f0cbd3ec | bellard | } |
27 | f0cbd3ec | bellard | |
28 | f0cbd3ec | bellard | void
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29 | 460fec67 | Jan Kiszka | if_init(Slirp *slirp) |
30 | f0cbd3ec | bellard | { |
31 | 460fec67 | Jan Kiszka | slirp->if_fastq.ifq_next = slirp->if_fastq.ifq_prev = &slirp->if_fastq; |
32 | 460fec67 | Jan Kiszka | slirp->if_batchq.ifq_next = slirp->if_batchq.ifq_prev = &slirp->if_batchq; |
33 | 460fec67 | Jan Kiszka | slirp->next_m = &slirp->if_batchq; |
34 | f0cbd3ec | bellard | } |
35 | f0cbd3ec | bellard | |
36 | f0cbd3ec | bellard | /*
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37 | f0cbd3ec | bellard | * if_output: Queue packet into an output queue.
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38 | 5fafdf24 | ths | * There are 2 output queue's, if_fastq and if_batchq.
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39 | f0cbd3ec | bellard | * Each output queue is a doubly linked list of double linked lists
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40 | f0cbd3ec | bellard | * of mbufs, each list belonging to one "session" (socket). This
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41 | f0cbd3ec | bellard | * way, we can output packets fairly by sending one packet from each
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42 | f0cbd3ec | bellard | * session, instead of all the packets from one session, then all packets
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43 | 5fafdf24 | ths | * from the next session, etc. Packets on the if_fastq get absolute
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44 | f0cbd3ec | bellard | * priority, but if one session hogs the link, it gets "downgraded"
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45 | f0cbd3ec | bellard | * to the batchq until it runs out of packets, then it'll return
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46 | f0cbd3ec | bellard | * to the fastq (eg. if the user does an ls -alR in a telnet session,
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47 | f0cbd3ec | bellard | * it'll temporarily get downgraded to the batchq)
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48 | f0cbd3ec | bellard | */
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49 | f0cbd3ec | bellard | void
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50 | 511d2b14 | blueswir1 | if_output(struct socket *so, struct mbuf *ifm) |
51 | f0cbd3ec | bellard | { |
52 | 460fec67 | Jan Kiszka | Slirp *slirp = ifm->slirp; |
53 | f0cbd3ec | bellard | struct mbuf *ifq;
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54 | f0cbd3ec | bellard | int on_fastq = 1; |
55 | 5fafdf24 | ths | |
56 | f0cbd3ec | bellard | DEBUG_CALL("if_output");
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57 | f0cbd3ec | bellard | DEBUG_ARG("so = %lx", (long)so); |
58 | f0cbd3ec | bellard | DEBUG_ARG("ifm = %lx", (long)ifm); |
59 | 5fafdf24 | ths | |
60 | f0cbd3ec | bellard | /*
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61 | f0cbd3ec | bellard | * First remove the mbuf from m_usedlist,
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62 | f0cbd3ec | bellard | * since we're gonna use m_next and m_prev ourselves
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63 | f0cbd3ec | bellard | * XXX Shouldn't need this, gotta change dtom() etc.
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64 | f0cbd3ec | bellard | */
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65 | f0cbd3ec | bellard | if (ifm->m_flags & M_USEDLIST) {
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66 | f0cbd3ec | bellard | remque(ifm); |
67 | f0cbd3ec | bellard | ifm->m_flags &= ~M_USEDLIST; |
68 | f0cbd3ec | bellard | } |
69 | 5fafdf24 | ths | |
70 | f0cbd3ec | bellard | /*
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71 | 3b46e624 | ths | * See if there's already a batchq list for this session.
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72 | f0cbd3ec | bellard | * This can include an interactive session, which should go on fastq,
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73 | f0cbd3ec | bellard | * but gets too greedy... hence it'll be downgraded from fastq to batchq.
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74 | f0cbd3ec | bellard | * We mustn't put this packet back on the fastq (or we'll send it out of order)
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75 | f0cbd3ec | bellard | * XXX add cache here?
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76 | f0cbd3ec | bellard | */
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77 | 460fec67 | Jan Kiszka | for (ifq = slirp->if_batchq.ifq_prev; ifq != &slirp->if_batchq;
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78 | 460fec67 | Jan Kiszka | ifq = ifq->ifq_prev) { |
79 | f0cbd3ec | bellard | if (so == ifq->ifq_so) {
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80 | f0cbd3ec | bellard | /* A match! */
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81 | f0cbd3ec | bellard | ifm->ifq_so = so; |
82 | f0cbd3ec | bellard | ifs_insque(ifm, ifq->ifs_prev); |
83 | f0cbd3ec | bellard | goto diddit;
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84 | f0cbd3ec | bellard | } |
85 | f0cbd3ec | bellard | } |
86 | 5fafdf24 | ths | |
87 | f0cbd3ec | bellard | /* No match, check which queue to put it on */
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88 | f0cbd3ec | bellard | if (so && (so->so_iptos & IPTOS_LOWDELAY)) {
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89 | 460fec67 | Jan Kiszka | ifq = slirp->if_fastq.ifq_prev; |
90 | f0cbd3ec | bellard | on_fastq = 1;
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91 | f0cbd3ec | bellard | /*
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92 | f0cbd3ec | bellard | * Check if this packet is a part of the last
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93 | f0cbd3ec | bellard | * packet's session
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94 | f0cbd3ec | bellard | */
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95 | f0cbd3ec | bellard | if (ifq->ifq_so == so) {
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96 | f0cbd3ec | bellard | ifm->ifq_so = so; |
97 | f0cbd3ec | bellard | ifs_insque(ifm, ifq->ifs_prev); |
98 | f0cbd3ec | bellard | goto diddit;
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99 | f0cbd3ec | bellard | } |
100 | f0cbd3ec | bellard | } else
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101 | 460fec67 | Jan Kiszka | ifq = slirp->if_batchq.ifq_prev; |
102 | 5fafdf24 | ths | |
103 | f0cbd3ec | bellard | /* Create a new doubly linked list for this session */
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104 | f0cbd3ec | bellard | ifm->ifq_so = so; |
105 | f0cbd3ec | bellard | ifs_init(ifm); |
106 | f0cbd3ec | bellard | insque(ifm, ifq); |
107 | 5fafdf24 | ths | |
108 | f0cbd3ec | bellard | diddit:
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109 | 460fec67 | Jan Kiszka | slirp->if_queued++; |
110 | 5fafdf24 | ths | |
111 | f0cbd3ec | bellard | if (so) {
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112 | f0cbd3ec | bellard | /* Update *_queued */
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113 | f0cbd3ec | bellard | so->so_queued++; |
114 | f0cbd3ec | bellard | so->so_nqueued++; |
115 | f0cbd3ec | bellard | /*
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116 | f0cbd3ec | bellard | * Check if the interactive session should be downgraded to
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117 | f0cbd3ec | bellard | * the batchq. A session is downgraded if it has queued 6
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118 | f0cbd3ec | bellard | * packets without pausing, and at least 3 of those packets
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119 | f0cbd3ec | bellard | * have been sent over the link
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120 | f0cbd3ec | bellard | * (XXX These are arbitrary numbers, probably not optimal..)
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121 | f0cbd3ec | bellard | */
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122 | 5fafdf24 | ths | if (on_fastq && ((so->so_nqueued >= 6) && |
123 | f0cbd3ec | bellard | (so->so_nqueued - so->so_queued) >= 3)) {
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124 | 3b46e624 | ths | |
125 | f0cbd3ec | bellard | /* Remove from current queue... */
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126 | f0cbd3ec | bellard | remque(ifm->ifs_next); |
127 | 3b46e624 | ths | |
128 | f0cbd3ec | bellard | /* ...And insert in the new. That'll teach ya! */
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129 | 460fec67 | Jan Kiszka | insque(ifm->ifs_next, &slirp->if_batchq); |
130 | f0cbd3ec | bellard | } |
131 | f0cbd3ec | bellard | } |
132 | f0cbd3ec | bellard | |
133 | f0cbd3ec | bellard | #ifndef FULL_BOLT
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134 | f0cbd3ec | bellard | /*
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135 | f0cbd3ec | bellard | * This prevents us from malloc()ing too many mbufs
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136 | f0cbd3ec | bellard | */
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137 | 460fec67 | Jan Kiszka | if_start(ifm->slirp); |
138 | f0cbd3ec | bellard | #endif
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139 | f0cbd3ec | bellard | } |
140 | f0cbd3ec | bellard | |
141 | f0cbd3ec | bellard | /*
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142 | f0cbd3ec | bellard | * Send a packet
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143 | f0cbd3ec | bellard | * We choose a packet based on it's position in the output queues;
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144 | f0cbd3ec | bellard | * If there are packets on the fastq, they are sent FIFO, before
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145 | f0cbd3ec | bellard | * everything else. Otherwise we choose the first packet from the
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146 | f0cbd3ec | bellard | * batchq and send it. the next packet chosen will be from the session
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147 | f0cbd3ec | bellard | * after this one, then the session after that one, and so on.. So,
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148 | f0cbd3ec | bellard | * for example, if there are 3 ftp session's fighting for bandwidth,
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149 | f0cbd3ec | bellard | * one packet will be sent from the first session, then one packet
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150 | f0cbd3ec | bellard | * from the second session, then one packet from the third, then back
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151 | f0cbd3ec | bellard | * to the first, etc. etc.
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152 | f0cbd3ec | bellard | */
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153 | f0cbd3ec | bellard | void
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154 | 460fec67 | Jan Kiszka | if_start(Slirp *slirp) |
155 | f0cbd3ec | bellard | { |
156 | f0cbd3ec | bellard | struct mbuf *ifm, *ifqt;
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157 | 5fafdf24 | ths | |
158 | f0cbd3ec | bellard | DEBUG_CALL("if_start");
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159 | 5fafdf24 | ths | |
160 | 460fec67 | Jan Kiszka | if (slirp->if_queued == 0) |
161 | f0cbd3ec | bellard | return; /* Nothing to do */ |
162 | 5fafdf24 | ths | |
163 | f0cbd3ec | bellard | again:
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164 | f0cbd3ec | bellard | /* check if we can really output */
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165 | 9f8bd042 | Jan Kiszka | if (!slirp_can_output(slirp->opaque))
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166 | f0cbd3ec | bellard | return;
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167 | f0cbd3ec | bellard | |
168 | f0cbd3ec | bellard | /*
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169 | f0cbd3ec | bellard | * See which queue to get next packet from
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170 | f0cbd3ec | bellard | * If there's something in the fastq, select it immediately
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171 | f0cbd3ec | bellard | */
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172 | 460fec67 | Jan Kiszka | if (slirp->if_fastq.ifq_next != &slirp->if_fastq) {
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173 | 460fec67 | Jan Kiszka | ifm = slirp->if_fastq.ifq_next; |
174 | f0cbd3ec | bellard | } else {
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175 | f0cbd3ec | bellard | /* Nothing on fastq, see if next_m is valid */
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176 | 460fec67 | Jan Kiszka | if (slirp->next_m != &slirp->if_batchq)
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177 | 460fec67 | Jan Kiszka | ifm = slirp->next_m; |
178 | f0cbd3ec | bellard | else
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179 | 460fec67 | Jan Kiszka | ifm = slirp->if_batchq.ifq_next; |
180 | 3b46e624 | ths | |
181 | f0cbd3ec | bellard | /* Set which packet to send on next iteration */
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182 | 460fec67 | Jan Kiszka | slirp->next_m = ifm->ifq_next; |
183 | f0cbd3ec | bellard | } |
184 | f0cbd3ec | bellard | /* Remove it from the queue */
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185 | f0cbd3ec | bellard | ifqt = ifm->ifq_prev; |
186 | f0cbd3ec | bellard | remque(ifm); |
187 | 460fec67 | Jan Kiszka | slirp->if_queued--; |
188 | 5fafdf24 | ths | |
189 | f0cbd3ec | bellard | /* If there are more packets for this session, re-queue them */
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190 | f0cbd3ec | bellard | if (ifm->ifs_next != /* ifm->ifs_prev != */ ifm) { |
191 | f0cbd3ec | bellard | insque(ifm->ifs_next, ifqt); |
192 | f0cbd3ec | bellard | ifs_remque(ifm); |
193 | f0cbd3ec | bellard | } |
194 | 5fafdf24 | ths | |
195 | f0cbd3ec | bellard | /* Update so_queued */
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196 | f0cbd3ec | bellard | if (ifm->ifq_so) {
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197 | f0cbd3ec | bellard | if (--ifm->ifq_so->so_queued == 0) |
198 | f0cbd3ec | bellard | /* If there's no more queued, reset nqueued */
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199 | f0cbd3ec | bellard | ifm->ifq_so->so_nqueued = 0;
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200 | f0cbd3ec | bellard | } |
201 | 5fafdf24 | ths | |
202 | f0cbd3ec | bellard | /* Encapsulate the packet for sending */
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203 | 460fec67 | Jan Kiszka | if_encap(slirp, (uint8_t *)ifm->m_data, ifm->m_len); |
204 | f0cbd3ec | bellard | |
205 | c9a62117 | bellard | m_free(ifm); |
206 | c9a62117 | bellard | |
207 | 460fec67 | Jan Kiszka | if (slirp->if_queued)
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208 | f0cbd3ec | bellard | goto again;
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209 | f0cbd3ec | bellard | } |