root / slirp / sbuf.c @ 44e4c0ba
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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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#include <slirp.h> |
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static void sbappendsb(struct sbuf *sb, struct mbuf *m); |
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void
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sbfree(struct sbuf *sb)
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{ |
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free(sb->sb_data); |
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} |
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void
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sbdrop(struct sbuf *sb, int num) |
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{ |
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/*
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* We can only drop how much we have
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* This should never succeed
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*/
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if(num > sb->sb_cc)
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num = sb->sb_cc; |
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sb->sb_cc -= num; |
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sb->sb_rptr += num; |
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if(sb->sb_rptr >= sb->sb_data + sb->sb_datalen)
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sb->sb_rptr -= sb->sb_datalen; |
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} |
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void
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sbreserve(struct sbuf *sb, int size) |
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{ |
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if (sb->sb_data) {
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/* Already alloced, realloc if necessary */
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if (sb->sb_datalen != size) {
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sb->sb_wptr = sb->sb_rptr = sb->sb_data = (char *)realloc(sb->sb_data, size);
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sb->sb_cc = 0;
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if (sb->sb_wptr)
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sb->sb_datalen = size; |
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else
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sb->sb_datalen = 0;
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} |
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} else {
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sb->sb_wptr = sb->sb_rptr = sb->sb_data = (char *)malloc(size);
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sb->sb_cc = 0;
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if (sb->sb_wptr)
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sb->sb_datalen = size; |
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else
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sb->sb_datalen = 0;
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} |
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} |
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/*
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* Try and write() to the socket, whatever doesn't get written
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* append to the buffer... for a host with a fast net connection,
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* this prevents an unnecessary copy of the data
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* (the socket is non-blocking, so we won't hang)
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*/
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void
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sbappend(struct socket *so, struct mbuf *m) |
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{ |
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int ret = 0; |
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DEBUG_CALL("sbappend");
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DEBUG_ARG("so = %lx", (long)so); |
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DEBUG_ARG("m = %lx", (long)m); |
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DEBUG_ARG("m->m_len = %d", m->m_len);
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/* Shouldn't happen, but... e.g. foreign host closes connection */
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if (m->m_len <= 0) { |
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m_free(m); |
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return;
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} |
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/*
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* If there is urgent data, call sosendoob
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* if not all was sent, sowrite will take care of the rest
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* (The rest of this function is just an optimisation)
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*/
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if (so->so_urgc) {
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sbappendsb(&so->so_rcv, m); |
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m_free(m); |
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sosendoob(so); |
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return;
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} |
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/*
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* We only write if there's nothing in the buffer,
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* ottherwise it'll arrive out of order, and hence corrupt
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*/
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if (!so->so_rcv.sb_cc)
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ret = slirp_send(so, m->m_data, m->m_len, 0);
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if (ret <= 0) { |
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/*
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* Nothing was written
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* It's possible that the socket has closed, but
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* we don't need to check because if it has closed,
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* it will be detected in the normal way by soread()
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*/
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sbappendsb(&so->so_rcv, m); |
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} else if (ret != m->m_len) { |
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/*
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* Something was written, but not everything..
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* sbappendsb the rest
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*/
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m->m_len -= ret; |
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m->m_data += ret; |
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sbappendsb(&so->so_rcv, m); |
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} /* else */
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/* Whatever happened, we free the mbuf */
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m_free(m); |
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} |
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/*
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* Copy the data from m into sb
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* The caller is responsible to make sure there's enough room
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*/
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static void |
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sbappendsb(struct sbuf *sb, struct mbuf *m) |
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{ |
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int len, n, nn;
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len = m->m_len; |
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if (sb->sb_wptr < sb->sb_rptr) {
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n = sb->sb_rptr - sb->sb_wptr; |
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if (n > len) n = len;
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memcpy(sb->sb_wptr, m->m_data, n); |
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} else {
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/* Do the right edge first */
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n = sb->sb_data + sb->sb_datalen - sb->sb_wptr; |
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if (n > len) n = len;
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memcpy(sb->sb_wptr, m->m_data, n); |
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len -= n; |
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if (len) {
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/* Now the left edge */
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nn = sb->sb_rptr - sb->sb_data; |
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if (nn > len) nn = len;
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memcpy(sb->sb_data,m->m_data+n,nn); |
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n += nn; |
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} |
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} |
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sb->sb_cc += n; |
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sb->sb_wptr += n; |
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if (sb->sb_wptr >= sb->sb_data + sb->sb_datalen)
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sb->sb_wptr -= sb->sb_datalen; |
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} |
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/*
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* Copy data from sbuf to a normal, straight buffer
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* Don't update the sbuf rptr, this will be
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* done in sbdrop when the data is acked
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*/
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void
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sbcopy(struct sbuf *sb, int off, int len, char *to) |
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{ |
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char *from;
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from = sb->sb_rptr + off; |
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if (from >= sb->sb_data + sb->sb_datalen)
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from -= sb->sb_datalen; |
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if (from < sb->sb_wptr) {
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if (len > sb->sb_cc) len = sb->sb_cc;
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memcpy(to,from,len); |
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} else {
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/* re-use off */
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off = (sb->sb_data + sb->sb_datalen) - from; |
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if (off > len) off = len;
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memcpy(to,from,off); |
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len -= off; |
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if (len)
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memcpy(to+off,sb->sb_data,len); |
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} |
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} |