/* * Copyright (c) 1995 Danny Gasparovski. * * Please read the file COPYRIGHT for the * terms and conditions of the copyright. */ #include <slirp.h> #include <main-loop.h> static void sbappendsb(struct sbuf *sb, struct mbuf *m); void sbfree(struct sbuf *sb) { free(sb->sb_data); } void sbdrop(struct sbuf *sb, int num) { int limit = sb->sb_datalen / 2; /* * We can only drop how much we have * This should never succeed */ if(num > sb->sb_cc) num = sb->sb_cc; sb->sb_cc -= num; sb->sb_rptr += num; if(sb->sb_rptr >= sb->sb_data + sb->sb_datalen) sb->sb_rptr -= sb->sb_datalen; if (sb->sb_cc < limit && sb->sb_cc + num >= limit) { qemu_notify_event(); } } void sbreserve(struct sbuf *sb, int size) { if (sb->sb_data) { /* Already alloced, realloc if necessary */ if (sb->sb_datalen != size) { sb->sb_wptr = sb->sb_rptr = sb->sb_data = (char *)realloc(sb->sb_data, size); sb->sb_cc = 0; if (sb->sb_wptr) sb->sb_datalen = size; else sb->sb_datalen = 0; } } else { sb->sb_wptr = sb->sb_rptr = sb->sb_data = (char *)malloc(size); sb->sb_cc = 0; if (sb->sb_wptr) sb->sb_datalen = size; else sb->sb_datalen = 0; } } /* * Try and write() to the socket, whatever doesn't get written * append to the buffer... for a host with a fast net connection, * this prevents an unnecessary copy of the data * (the socket is non-blocking, so we won't hang) */ void sbappend(struct socket *so, struct mbuf *m) { int ret = 0; DEBUG_CALL("sbappend"); DEBUG_ARG("so = %lx", (long)so); DEBUG_ARG("m = %lx", (long)m); DEBUG_ARG("m->m_len = %d", m->m_len); /* Shouldn't happen, but... e.g. foreign host closes connection */ if (m->m_len <= 0) { m_free(m); return; } /* * If there is urgent data, call sosendoob * if not all was sent, sowrite will take care of the rest * (The rest of this function is just an optimisation) */ if (so->so_urgc) { sbappendsb(&so->so_rcv, m); m_free(m); sosendoob(so); return; } /* * We only write if there's nothing in the buffer, * ottherwise it'll arrive out of order, and hence corrupt */ if (!so->so_rcv.sb_cc) ret = slirp_send(so, m->m_data, m->m_len, 0); if (ret <= 0) { /* * Nothing was written * It's possible that the socket has closed, but * we don't need to check because if it has closed, * it will be detected in the normal way by soread() */ sbappendsb(&so->so_rcv, m); } else if (ret != m->m_len) { /* * Something was written, but not everything.. * sbappendsb the rest */ m->m_len -= ret; m->m_data += ret; sbappendsb(&so->so_rcv, m); } /* else */ /* Whatever happened, we free the mbuf */ m_free(m); } /* * Copy the data from m into sb * The caller is responsible to make sure there's enough room */ static void sbappendsb(struct sbuf *sb, struct mbuf *m) { int len, n, nn; len = m->m_len; if (sb->sb_wptr < sb->sb_rptr) { n = sb->sb_rptr - sb->sb_wptr; if (n > len) n = len; memcpy(sb->sb_wptr, m->m_data, n); } else { /* Do the right edge first */ n = sb->sb_data + sb->sb_datalen - sb->sb_wptr; if (n > len) n = len; memcpy(sb->sb_wptr, m->m_data, n); len -= n; if (len) { /* Now the left edge */ nn = sb->sb_rptr - sb->sb_data; if (nn > len) nn = len; memcpy(sb->sb_data,m->m_data+n,nn); n += nn; } } sb->sb_cc += n; sb->sb_wptr += n; if (sb->sb_wptr >= sb->sb_data + sb->sb_datalen) sb->sb_wptr -= sb->sb_datalen; } /* * Copy data from sbuf to a normal, straight buffer * Don't update the sbuf rptr, this will be * done in sbdrop when the data is acked */ void sbcopy(struct sbuf *sb, int off, int len, char *to) { char *from; from = sb->sb_rptr + off; if (from >= sb->sb_data + sb->sb_datalen) from -= sb->sb_datalen; if (from < sb->sb_wptr) { if (len > sb->sb_cc) len = sb->sb_cc; memcpy(to,from,len); } else { /* re-use off */ off = (sb->sb_data + sb->sb_datalen) - from; if (off > len) off = len; memcpy(to,from,off); len -= off; if (len) memcpy(to+off,sb->sb_data,len); } }