Annotation of qemu/slirp/sbuf.c, revision 1.1.1.4
1.1 root 1: /*
2: * Copyright (c) 1995 Danny Gasparovski.
1.1.1.2 root 3: *
4: * Please read the file COPYRIGHT for the
1.1 root 5: * terms and conditions of the copyright.
6: */
7:
8: #include <slirp.h>
9:
1.1.1.2 root 10: static void sbappendsb(struct sbuf *sb, struct mbuf *m);
11:
1.1 root 12: void
1.1.1.4 ! root 13: sbfree(struct sbuf *sb)
1.1 root 14: {
15: free(sb->sb_data);
16: }
17:
18: void
1.1.1.4 ! root 19: sbdrop(struct sbuf *sb, int num)
1.1 root 20: {
1.1.1.2 root 21: /*
1.1 root 22: * We can only drop how much we have
1.1.1.2 root 23: * This should never succeed
1.1 root 24: */
25: if(num > sb->sb_cc)
26: num = sb->sb_cc;
27: sb->sb_cc -= num;
28: sb->sb_rptr += num;
29: if(sb->sb_rptr >= sb->sb_data + sb->sb_datalen)
30: sb->sb_rptr -= sb->sb_datalen;
1.1.1.2 root 31:
1.1 root 32: }
33:
34: void
1.1.1.4 ! root 35: sbreserve(struct sbuf *sb, int size)
1.1 root 36: {
37: if (sb->sb_data) {
38: /* Already alloced, realloc if necessary */
39: if (sb->sb_datalen != size) {
40: sb->sb_wptr = sb->sb_rptr = sb->sb_data = (char *)realloc(sb->sb_data, size);
41: sb->sb_cc = 0;
42: if (sb->sb_wptr)
43: sb->sb_datalen = size;
44: else
45: sb->sb_datalen = 0;
46: }
47: } else {
48: sb->sb_wptr = sb->sb_rptr = sb->sb_data = (char *)malloc(size);
49: sb->sb_cc = 0;
50: if (sb->sb_wptr)
51: sb->sb_datalen = size;
52: else
53: sb->sb_datalen = 0;
54: }
55: }
56:
57: /*
58: * Try and write() to the socket, whatever doesn't get written
59: * append to the buffer... for a host with a fast net connection,
60: * this prevents an unnecessary copy of the data
61: * (the socket is non-blocking, so we won't hang)
62: */
63: void
1.1.1.4 ! root 64: sbappend(struct socket *so, struct mbuf *m)
1.1 root 65: {
66: int ret = 0;
1.1.1.2 root 67:
1.1 root 68: DEBUG_CALL("sbappend");
69: DEBUG_ARG("so = %lx", (long)so);
70: DEBUG_ARG("m = %lx", (long)m);
71: DEBUG_ARG("m->m_len = %d", m->m_len);
1.1.1.2 root 72:
1.1 root 73: /* Shouldn't happen, but... e.g. foreign host closes connection */
74: if (m->m_len <= 0) {
75: m_free(m);
76: return;
77: }
1.1.1.2 root 78:
1.1 root 79: /*
80: * If there is urgent data, call sosendoob
81: * if not all was sent, sowrite will take care of the rest
82: * (The rest of this function is just an optimisation)
83: */
84: if (so->so_urgc) {
85: sbappendsb(&so->so_rcv, m);
86: m_free(m);
87: sosendoob(so);
88: return;
89: }
1.1.1.2 root 90:
1.1 root 91: /*
92: * We only write if there's nothing in the buffer,
93: * ottherwise it'll arrive out of order, and hence corrupt
94: */
95: if (!so->so_rcv.sb_cc)
1.1.1.3 root 96: ret = slirp_send(so, m->m_data, m->m_len, 0);
1.1.1.2 root 97:
1.1 root 98: if (ret <= 0) {
1.1.1.2 root 99: /*
1.1 root 100: * Nothing was written
101: * It's possible that the socket has closed, but
102: * we don't need to check because if it has closed,
103: * it will be detected in the normal way by soread()
104: */
105: sbappendsb(&so->so_rcv, m);
106: } else if (ret != m->m_len) {
107: /*
108: * Something was written, but not everything..
109: * sbappendsb the rest
110: */
111: m->m_len -= ret;
112: m->m_data += ret;
113: sbappendsb(&so->so_rcv, m);
114: } /* else */
115: /* Whatever happened, we free the mbuf */
116: m_free(m);
117: }
118:
119: /*
120: * Copy the data from m into sb
121: * The caller is responsible to make sure there's enough room
122: */
1.1.1.2 root 123: static void
124: sbappendsb(struct sbuf *sb, struct mbuf *m)
1.1 root 125: {
126: int len, n, nn;
1.1.1.2 root 127:
1.1 root 128: len = m->m_len;
129:
130: if (sb->sb_wptr < sb->sb_rptr) {
131: n = sb->sb_rptr - sb->sb_wptr;
132: if (n > len) n = len;
133: memcpy(sb->sb_wptr, m->m_data, n);
134: } else {
135: /* Do the right edge first */
136: n = sb->sb_data + sb->sb_datalen - sb->sb_wptr;
137: if (n > len) n = len;
138: memcpy(sb->sb_wptr, m->m_data, n);
139: len -= n;
140: if (len) {
141: /* Now the left edge */
142: nn = sb->sb_rptr - sb->sb_data;
143: if (nn > len) nn = len;
144: memcpy(sb->sb_data,m->m_data+n,nn);
145: n += nn;
146: }
147: }
148:
149: sb->sb_cc += n;
150: sb->sb_wptr += n;
151: if (sb->sb_wptr >= sb->sb_data + sb->sb_datalen)
152: sb->sb_wptr -= sb->sb_datalen;
153: }
154:
155: /*
156: * Copy data from sbuf to a normal, straight buffer
157: * Don't update the sbuf rptr, this will be
158: * done in sbdrop when the data is acked
159: */
160: void
1.1.1.4 ! root 161: sbcopy(struct sbuf *sb, int off, int len, char *to)
1.1 root 162: {
163: char *from;
1.1.1.2 root 164:
1.1 root 165: from = sb->sb_rptr + off;
166: if (from >= sb->sb_data + sb->sb_datalen)
167: from -= sb->sb_datalen;
168:
169: if (from < sb->sb_wptr) {
170: if (len > sb->sb_cc) len = sb->sb_cc;
171: memcpy(to,from,len);
172: } else {
173: /* re-use off */
174: off = (sb->sb_data + sb->sb_datalen) - from;
175: if (off > len) off = len;
176: memcpy(to,from,off);
177: len -= off;
178: if (len)
179: memcpy(to+off,sb->sb_data,len);
180: }
181: }
unix.superglobalmegacorp.com
![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to sbuf.c CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [Qemu by Fabrice Bellard] / qemu / slirp