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