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1.1 root 1: /*
2: * Copyright (c) 1995 Danny Gasparovski.
3: *
4: * Please read the file COPYRIGHT for the
5: * terms and conditions of the copyright.
6: */
7:
8: #include <stdlib.h>
9: #include <slirp.h>
10:
11: /* Done as a macro in socket.h */
12: /* int
13: * sbspace(struct sockbuff *sb)
14: * {
15: * return SB_DATALEN - sb->sb_cc;
16: * }
17: */
18:
19: void
20: sbfree(sb)
21: struct sbuf *sb;
22: {
23: free(sb->sb_data);
24: }
25:
26: void
27: sbdrop(sb, num)
28: struct sbuf *sb;
29: int num;
30: {
31: /*
32: * We can only drop how much we have
33: * This should never succeed
34: */
35: if(num > sb->sb_cc)
36: num = sb->sb_cc;
37: sb->sb_cc -= num;
38: sb->sb_rptr += num;
39: if(sb->sb_rptr >= sb->sb_data + sb->sb_datalen)
40: sb->sb_rptr -= sb->sb_datalen;
41:
42: }
43:
44: void
45: sbreserve(sb, size)
46: struct sbuf *sb;
47: int size;
48: {
49: if (sb->sb_data) {
50: /* Already alloced, realloc if necessary */
51: if (sb->sb_datalen != size) {
52: sb->sb_wptr = sb->sb_rptr = sb->sb_data = (char *)realloc(sb->sb_data, size);
53: sb->sb_cc = 0;
54: if (sb->sb_wptr)
55: sb->sb_datalen = size;
56: else
57: sb->sb_datalen = 0;
58: }
59: } else {
60: sb->sb_wptr = sb->sb_rptr = sb->sb_data = (char *)malloc(size);
61: sb->sb_cc = 0;
62: if (sb->sb_wptr)
63: sb->sb_datalen = size;
64: else
65: sb->sb_datalen = 0;
66: }
67: }
68:
69: /*
70: * Try and write() to the socket, whatever doesn't get written
71: * append to the buffer... for a host with a fast net connection,
72: * this prevents an unnecessary copy of the data
73: * (the socket is non-blocking, so we won't hang)
74: */
75: void
76: sbappend(so, m)
77: struct socket *so;
78: struct mbuf *m;
79: {
80: int ret = 0;
81:
82: DEBUG_CALL("sbappend");
83: DEBUG_ARG("so = %lx", (long)so);
84: DEBUG_ARG("m = %lx", (long)m);
85: DEBUG_ARG("m->m_len = %d", m->m_len);
86:
87: /* Shouldn't happen, but... e.g. foreign host closes connection */
88: if (m->m_len <= 0) {
89: m_free(m);
90: return;
91: }
92:
93: /*
94: * If there is urgent data, call sosendoob
95: * if not all was sent, sowrite will take care of the rest
96: * (The rest of this function is just an optimisation)
97: */
98: if (so->so_urgc) {
99: sbappendsb(&so->so_rcv, m);
100: m_free(m);
101: sosendoob(so);
102: return;
103: }
104:
105: /*
106: * We only write if there's nothing in the buffer,
107: * ottherwise it'll arrive out of order, and hence corrupt
108: */
109: if (!so->so_rcv.sb_cc)
110: ret = send(so->s, m->m_data, m->m_len, 0);
111:
112: if (ret <= 0) {
113: /*
114: * Nothing was written
115: * It's possible that the socket has closed, but
116: * we don't need to check because if it has closed,
117: * it will be detected in the normal way by soread()
118: */
119: sbappendsb(&so->so_rcv, m);
120: } else if (ret != m->m_len) {
121: /*
122: * Something was written, but not everything..
123: * sbappendsb the rest
124: */
125: m->m_len -= ret;
126: m->m_data += ret;
127: sbappendsb(&so->so_rcv, m);
128: } /* else */
129: /* Whatever happened, we free the mbuf */
130: m_free(m);
131: }
132:
133: /*
134: * Copy the data from m into sb
135: * The caller is responsible to make sure there's enough room
136: */
137: void
138: sbappendsb(sb, m)
139: struct sbuf *sb;
140: struct mbuf *m;
141: {
142: int len, n, nn;
143:
144: len = m->m_len;
145:
146: if (sb->sb_wptr < sb->sb_rptr) {
147: n = sb->sb_rptr - sb->sb_wptr;
148: if (n > len) n = len;
149: memcpy(sb->sb_wptr, m->m_data, n);
150: } else {
151: /* Do the right edge first */
152: n = sb->sb_data + sb->sb_datalen - sb->sb_wptr;
153: if (n > len) n = len;
154: memcpy(sb->sb_wptr, m->m_data, n);
155: len -= n;
156: if (len) {
157: /* Now the left edge */
158: nn = sb->sb_rptr - sb->sb_data;
159: if (nn > len) nn = len;
160: memcpy(sb->sb_data,m->m_data+n,nn);
161: n += nn;
162: }
163: }
164:
165: sb->sb_cc += n;
166: sb->sb_wptr += n;
167: if (sb->sb_wptr >= sb->sb_data + sb->sb_datalen)
168: sb->sb_wptr -= sb->sb_datalen;
169: }
170:
171: /*
172: * Copy data from sbuf to a normal, straight buffer
173: * Don't update the sbuf rptr, this will be
174: * done in sbdrop when the data is acked
175: */
176: void
177: sbcopy(sb, off, len, to)
178: struct sbuf *sb;
179: int off;
180: int len;
181: char *to;
182: {
183: char *from;
184:
185: from = sb->sb_rptr + off;
186: if (from >= sb->sb_data + sb->sb_datalen)
187: from -= sb->sb_datalen;
188:
189: if (from < sb->sb_wptr) {
190: if (len > sb->sb_cc) len = sb->sb_cc;
191: memcpy(to,from,len);
192: } else {
193: /* re-use off */
194: off = (sb->sb_data + sb->sb_datalen) - from;
195: if (off > len) off = len;
196: memcpy(to,from,off);
197: len -= off;
198: if (len)
199: memcpy(to+off,sb->sb_data,len);
200: }
201: }
202:
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