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/* |
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* Copyright (c) 1995 Danny Gasparovski. |
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* |
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* Please read the file COPYRIGHT for the |
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* terms and conditions of the copyright. |
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*/ |
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|
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#include <slirp.h> |
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|
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int if_mtu, if_mru; |
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int if_comp; |
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int if_maxlinkhdr; |
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int if_queued = 0; /* Number of packets queued so far */ |
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int if_thresh = 10; /* Number of packets queued before we start sending |
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* (to prevent allocing too many mbufs) */ |
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|
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struct mbuf if_fastq; /* fast queue (for interactive data) */ |
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struct mbuf if_batchq; /* queue for non-interactive data */ |
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struct mbuf *next_m; /* Pointer to next mbuf to output */ |
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|
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#define ifs_init(ifm) ((ifm)->ifs_next = (ifm)->ifs_prev = (ifm)) |
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|
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void |
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ifs_insque(ifm, ifmhead) |
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struct mbuf *ifm, *ifmhead; |
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{ |
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ifm->ifs_next = ifmhead->ifs_next; |
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ifmhead->ifs_next = ifm; |
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ifm->ifs_prev = ifmhead; |
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ifm->ifs_next->ifs_prev = ifm; |
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} |
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|
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void |
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ifs_remque(ifm) |
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struct mbuf *ifm; |
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{ |
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ifm->ifs_prev->ifs_next = ifm->ifs_next; |
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ifm->ifs_next->ifs_prev = ifm->ifs_prev; |
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} |
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|
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void |
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if_init() |
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{ |
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#if 0 |
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/* |
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* Set if_maxlinkhdr to 48 because it's 40 bytes for TCP/IP, |
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* and 8 bytes for PPP, but need to have it on an 8byte boundary |
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*/ |
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#ifdef USE_PPP |
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if_maxlinkhdr = 48; |
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#else |
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if_maxlinkhdr = 40; |
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#endif |
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#else |
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/* 2 for alignment, 14 for ethernet, 40 for TCP/IP */ |
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if_maxlinkhdr = 2 + 14 + 40; |
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#endif |
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if_mtu = 1500; |
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if_mru = 1500; |
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if_comp = IF_AUTOCOMP; |
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if_fastq.ifq_next = if_fastq.ifq_prev = &if_fastq; |
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if_batchq.ifq_next = if_batchq.ifq_prev = &if_batchq; |
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// sl_compress_init(&comp_s); |
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next_m = &if_batchq; |
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} |
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|
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#if 0 |
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/* |
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* This shouldn't be needed since the modem is blocking and |
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* we don't expect any signals, but what the hell.. |
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*/ |
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inline int |
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writen(fd, bptr, n) |
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int fd; |
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char *bptr; |
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int n; |
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{ |
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int ret; |
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int total; |
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|
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/* This should succeed most of the time */ |
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ret = send(fd, bptr, n,0); |
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if (ret == n || ret <= 0) |
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return ret; |
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|
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/* Didn't write everything, go into the loop */ |
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total = ret; |
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while (n > total) { |
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ret = send(fd, bptr+total, n-total,0); |
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if (ret <= 0) |
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return ret; |
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total += ret; |
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} |
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return total; |
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} |
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|
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/* |
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* if_input - read() the tty, do "top level" processing (ie: check for any escapes), |
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* and pass onto (*ttyp->if_input) |
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* |
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* XXXXX Any zeros arriving by themselves are NOT placed into the arriving packet. |
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*/ |
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#define INBUFF_SIZE 2048 /* XXX */ |
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void |
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if_input(ttyp) |
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struct ttys *ttyp; |
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{ |
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u_char if_inbuff[INBUFF_SIZE]; |
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int if_n; |
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|
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DEBUG_CALL("if_input"); |
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DEBUG_ARG("ttyp = %lx", (long)ttyp); |
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|
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if_n = recv(ttyp->fd, (char *)if_inbuff, INBUFF_SIZE,0); |
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|
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DEBUG_MISC((dfd, " read %d bytes\n", if_n)); |
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|
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if (if_n <= 0) { |
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if (if_n == 0 || (errno != EINTR && errno != EAGAIN)) { |
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if (ttyp->up) |
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link_up--; |
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tty_detached(ttyp, 0); |
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} |
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return; |
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} |
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if (if_n == 1) { |
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if (*if_inbuff == '0') { |
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ttyp->ones = 0; |
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if (++ttyp->zeros >= 5) |
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slirp_exit(0); |
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return; |
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} |
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if (*if_inbuff == '1') { |
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ttyp->zeros = 0; |
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if (++ttyp->ones >= 5) |
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tty_detached(ttyp, 0); |
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return; |
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} |
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} |
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ttyp->ones = ttyp->zeros = 0; |
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|
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(*ttyp->if_input)(ttyp, if_inbuff, if_n); |
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} |
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#endif |
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|
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/* |
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* if_output: Queue packet into an output queue. |
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* There are 2 output queue's, if_fastq and if_batchq. |
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* Each output queue is a doubly linked list of double linked lists |
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* of mbufs, each list belonging to one "session" (socket). This |
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* way, we can output packets fairly by sending one packet from each |
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* session, instead of all the packets from one session, then all packets |
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* from the next session, etc. Packets on the if_fastq get absolute |
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* priority, but if one session hogs the link, it gets "downgraded" |
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* to the batchq until it runs out of packets, then it'll return |
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* to the fastq (eg. if the user does an ls -alR in a telnet session, |
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* it'll temporarily get downgraded to the batchq) |
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*/ |
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void |
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if_output(so, ifm) |
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struct socket *so; |
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struct mbuf *ifm; |
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{ |
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struct mbuf *ifq; |
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int on_fastq = 1; |
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|
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DEBUG_CALL("if_output"); |
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DEBUG_ARG("so = %lx", (long)so); |
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DEBUG_ARG("ifm = %lx", (long)ifm); |
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|
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/* |
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* First remove the mbuf from m_usedlist, |
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* since we're gonna use m_next and m_prev ourselves |
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* XXX Shouldn't need this, gotta change dtom() etc. |
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*/ |
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if (ifm->m_flags & M_USEDLIST) { |
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remque(ifm); |
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ifm->m_flags &= ~M_USEDLIST; |
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} |
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|
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/* |
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* See if there's already a batchq list for this session. |
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* This can include an interactive session, which should go on fastq, |
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* but gets too greedy... hence it'll be downgraded from fastq to batchq. |
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* We mustn't put this packet back on the fastq (or we'll send it out of order) |
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* XXX add cache here? |
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*/ |
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for (ifq = if_batchq.ifq_prev; ifq != &if_batchq; ifq = ifq->ifq_prev) { |
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if (so == ifq->ifq_so) { |
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/* A match! */ |
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ifm->ifq_so = so; |
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ifs_insque(ifm, ifq->ifs_prev); |
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goto diddit; |
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} |
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} |
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|
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/* No match, check which queue to put it on */ |
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if (so && (so->so_iptos & IPTOS_LOWDELAY)) { |
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ifq = if_fastq.ifq_prev; |
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on_fastq = 1; |
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/* |
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* Check if this packet is a part of the last |
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* packet's session |
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*/ |
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if (ifq->ifq_so == so) { |
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ifm->ifq_so = so; |
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ifs_insque(ifm, ifq->ifs_prev); |
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goto diddit; |
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} |
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} else |
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ifq = if_batchq.ifq_prev; |
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|
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/* Create a new doubly linked list for this session */ |
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ifm->ifq_so = so; |
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ifs_init(ifm); |
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insque(ifm, ifq); |
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|
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diddit: |
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++if_queued; |
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|
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if (so) { |
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/* Update *_queued */ |
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so->so_queued++; |
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so->so_nqueued++; |
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/* |
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* Check if the interactive session should be downgraded to |
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* the batchq. A session is downgraded if it has queued 6 |
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* packets without pausing, and at least 3 of those packets |
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* have been sent over the link |
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* (XXX These are arbitrary numbers, probably not optimal..) |
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*/ |
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if (on_fastq && ((so->so_nqueued >= 6) && |
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(so->so_nqueued - so->so_queued) >= 3)) { |
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|
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/* Remove from current queue... */ |
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remque(ifm->ifs_next); |
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|
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/* ...And insert in the new. That'll teach ya! */ |
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insque(ifm->ifs_next, &if_batchq); |
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} |
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} |
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|
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#ifndef FULL_BOLT |
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/* |
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* This prevents us from malloc()ing too many mbufs |
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*/ |
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if (link_up) { |
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/* if_start will check towrite */ |
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if_start(); |
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} |
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#endif |
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} |
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|
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/* |
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* Send a packet |
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* We choose a packet based on it's position in the output queues; |
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* If there are packets on the fastq, they are sent FIFO, before |
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* everything else. Otherwise we choose the first packet from the |
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* batchq and send it. the next packet chosen will be from the session |
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* after this one, then the session after that one, and so on.. So, |
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* for example, if there are 3 ftp session's fighting for bandwidth, |
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* one packet will be sent from the first session, then one packet |
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* from the second session, then one packet from the third, then back |
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* to the first, etc. etc. |
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*/ |
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void |
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if_start(void) |
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{ |
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struct mbuf *ifm, *ifqt; |
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|
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DEBUG_CALL("if_start"); |
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|
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if (if_queued == 0) |
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return; /* Nothing to do */ |
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|
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again: |
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/* check if we can really output */ |
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if (!slirp_can_output()) |
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return; |
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|
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/* |
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* See which queue to get next packet from |
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* If there's something in the fastq, select it immediately |
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*/ |
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if (if_fastq.ifq_next != &if_fastq) { |
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ifm = if_fastq.ifq_next; |
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} else { |
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/* Nothing on fastq, see if next_m is valid */ |
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if (next_m != &if_batchq) |
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ifm = next_m; |
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else |
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ifm = if_batchq.ifq_next; |
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|
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/* Set which packet to send on next iteration */ |
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next_m = ifm->ifq_next; |
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} |
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/* Remove it from the queue */ |
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ifqt = ifm->ifq_prev; |
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remque(ifm); |
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--if_queued; |
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|
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/* If there are more packets for this session, re-queue them */ |
| 303 |
if (ifm->ifs_next != /* ifm->ifs_prev != */ ifm) { |
| 304 |
insque(ifm->ifs_next, ifqt); |
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ifs_remque(ifm); |
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} |
| 307 |
|
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/* Update so_queued */ |
| 309 |
if (ifm->ifq_so) { |
| 310 |
if (--ifm->ifq_so->so_queued == 0) |
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/* If there's no more queued, reset nqueued */ |
| 312 |
ifm->ifq_so->so_nqueued = 0; |
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} |
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|
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/* Encapsulate the packet for sending */ |
| 316 |
if_encap((uint8_t*)ifm->m_data, ifm->m_len); |
| 317 |
|
| 318 |
m_free(ifm); |
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|
| 320 |
if (if_queued) |
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goto again; |
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} |
