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