![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to mbuf.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|
Return to mbuf.c CVS log | Up to [Qemu by Fabrice Bellard] / qemu / slirp |
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: /*
9: * mbuf's in SLiRP are much simpler than the real mbufs in
10: * FreeBSD. They are fixed size, determined by the MTU,
11: * so that one whole packet can fit. Mbuf's cannot be
12: * chained together. If there's more data than the mbuf
13: * could hold, an external malloced buffer is pointed to
14: * by m_ext (and the data pointers) and M_EXT is set in
15: * the flags
16: */
17:
18: #include <slirp.h>
19:
1.1.1.3 root 20: #define MBUF_THRESH 30
21:
22: /*
23: * Find a nice value for msize
24: * XXX if_maxlinkhdr already in mtu
25: */
1.1.1.7 root 26: #define SLIRP_MSIZE (IF_MTU + IF_MAXLINKHDR + offsetof(struct mbuf, m_dat) + 6)
1.1 root 27:
28: void
1.1.1.5 root 29: m_init(Slirp *slirp)
1.1 root 30: {
1.1.1.5 root 31: slirp->m_freelist.m_next = slirp->m_freelist.m_prev = &slirp->m_freelist;
32: slirp->m_usedlist.m_next = slirp->m_usedlist.m_prev = &slirp->m_usedlist;
1.1 root 33: }
34:
1.1.1.9 ! root 35: void m_cleanup(Slirp *slirp)
! 36: {
! 37: struct mbuf *m, *next;
! 38:
! 39: m = slirp->m_usedlist.m_next;
! 40: while (m != &slirp->m_usedlist) {
! 41: next = m->m_next;
! 42: if (m->m_flags & M_EXT) {
! 43: free(m->m_ext);
! 44: }
! 45: free(m);
! 46: m = next;
! 47: }
! 48: m = slirp->m_freelist.m_next;
! 49: while (m != &slirp->m_freelist) {
! 50: next = m->m_next;
! 51: free(m);
! 52: m = next;
! 53: }
! 54: }
! 55:
1.1 root 56: /*
57: * Get an mbuf from the free list, if there are none
58: * malloc one
1.1.1.3 root 59: *
1.1 root 60: * Because fragmentation can occur if we alloc new mbufs and
61: * free old mbufs, we mark all mbufs above mbuf_thresh as M_DOFREE,
62: * which tells m_free to actually free() it
63: */
64: struct mbuf *
1.1.1.5 root 65: m_get(Slirp *slirp)
1.1 root 66: {
67: register struct mbuf *m;
68: int flags = 0;
1.1.1.3 root 69:
1.1 root 70: DEBUG_CALL("m_get");
1.1.1.3 root 71:
1.1.1.5 root 72: if (slirp->m_freelist.m_next == &slirp->m_freelist) {
1.1.1.4 root 73: m = (struct mbuf *)malloc(SLIRP_MSIZE);
1.1 root 74: if (m == NULL) goto end_error;
1.1.1.5 root 75: slirp->mbuf_alloced++;
76: if (slirp->mbuf_alloced > MBUF_THRESH)
1.1 root 77: flags = M_DOFREE;
1.1.1.5 root 78: m->slirp = slirp;
1.1 root 79: } else {
1.1.1.5 root 80: m = slirp->m_freelist.m_next;
1.1 root 81: remque(m);
82: }
1.1.1.3 root 83:
1.1 root 84: /* Insert it in the used list */
1.1.1.5 root 85: insque(m,&slirp->m_usedlist);
1.1 root 86: m->m_flags = (flags | M_USEDLIST);
1.1.1.3 root 87:
1.1 root 88: /* Initialise it */
1.1.1.7 root 89: m->m_size = SLIRP_MSIZE - offsetof(struct mbuf, m_dat);
1.1 root 90: m->m_data = m->m_dat;
91: m->m_len = 0;
1.1.1.5 root 92: m->m_nextpkt = NULL;
93: m->m_prevpkt = NULL;
1.1.1.8 root 94: m->arp_requested = false;
95: m->expiration_date = (uint64_t)-1;
1.1 root 96: end_error:
97: DEBUG_ARG("m = %lx", (long )m);
98: return m;
99: }
100:
101: void
1.1.1.5 root 102: m_free(struct mbuf *m)
1.1 root 103: {
1.1.1.3 root 104:
1.1 root 105: DEBUG_CALL("m_free");
106: DEBUG_ARG("m = %lx", (long )m);
1.1.1.3 root 107:
1.1 root 108: if(m) {
109: /* Remove from m_usedlist */
110: if (m->m_flags & M_USEDLIST)
111: remque(m);
1.1.1.3 root 112:
1.1 root 113: /* If it's M_EXT, free() it */
114: if (m->m_flags & M_EXT)
115: free(m->m_ext);
116:
117: /*
118: * Either free() it or put it on the free list
119: */
120: if (m->m_flags & M_DOFREE) {
1.1.1.5 root 121: m->slirp->mbuf_alloced--;
1.1.1.6 root 122: free(m);
1.1 root 123: } else if ((m->m_flags & M_FREELIST) == 0) {
1.1.1.5 root 124: insque(m,&m->slirp->m_freelist);
1.1 root 125: m->m_flags = M_FREELIST; /* Clobber other flags */
126: }
127: } /* if(m) */
128: }
129:
130: /*
131: * Copy data from one mbuf to the end of
132: * the other.. if result is too big for one mbuf, malloc()
133: * an M_EXT data segment
134: */
135: void
1.1.1.5 root 136: m_cat(struct mbuf *m, struct mbuf *n)
1.1 root 137: {
138: /*
139: * If there's no room, realloc
140: */
141: if (M_FREEROOM(m) < n->m_len)
142: m_inc(m,m->m_size+MINCSIZE);
1.1.1.3 root 143:
1.1 root 144: memcpy(m->m_data+m->m_len, n->m_data, n->m_len);
145: m->m_len += n->m_len;
146:
147: m_free(n);
148: }
149:
150:
151: /* make m size bytes large */
152: void
1.1.1.5 root 153: m_inc(struct mbuf *m, int size)
1.1 root 154: {
1.1.1.2 root 155: int datasize;
156:
1.1 root 157: /* some compiles throw up on gotos. This one we can fake. */
158: if(m->m_size>size) return;
159:
160: if (m->m_flags & M_EXT) {
1.1.1.2 root 161: datasize = m->m_data - m->m_ext;
1.1 root 162: m->m_ext = (char *)realloc(m->m_ext,size);
1.1.1.2 root 163: m->m_data = m->m_ext + datasize;
1.1 root 164: } else {
165: char *dat;
166: datasize = m->m_data - m->m_dat;
167: dat = (char *)malloc(size);
168: memcpy(dat, m->m_dat, m->m_size);
1.1.1.3 root 169:
1.1 root 170: m->m_ext = dat;
171: m->m_data = m->m_ext + datasize;
172: m->m_flags |= M_EXT;
173: }
1.1.1.3 root 174:
1.1 root 175: m->m_size = size;
176:
177: }
178:
179:
180:
181: void
1.1.1.5 root 182: m_adj(struct mbuf *m, int len)
1.1 root 183: {
184: if (m == NULL)
185: return;
186: if (len >= 0) {
187: /* Trim from head */
188: m->m_data += len;
189: m->m_len -= len;
190: } else {
191: /* Trim from tail */
192: len = -len;
193: m->m_len -= len;
194: }
195: }
196:
197:
198: /*
199: * Copy len bytes from m, starting off bytes into n
200: */
201: int
1.1.1.5 root 202: m_copy(struct mbuf *n, struct mbuf *m, int off, int len)
1.1 root 203: {
204: if (len > M_FREEROOM(n))
205: return -1;
206:
207: memcpy((n->m_data + n->m_len), (m->m_data + off), len);
208: n->m_len += len;
209: return 0;
210: }
211:
212:
213: /*
214: * Given a pointer into an mbuf, return the mbuf
215: * XXX This is a kludge, I should eliminate the need for it
216: * Fortunately, it's not used often
217: */
218: struct mbuf *
1.1.1.5 root 219: dtom(Slirp *slirp, void *dat)
1.1 root 220: {
221: struct mbuf *m;
1.1.1.3 root 222:
1.1 root 223: DEBUG_CALL("dtom");
224: DEBUG_ARG("dat = %lx", (long )dat);
225:
226: /* bug corrected for M_EXT buffers */
1.1.1.5 root 227: for (m = slirp->m_usedlist.m_next; m != &slirp->m_usedlist;
228: m = m->m_next) {
1.1 root 229: if (m->m_flags & M_EXT) {
230: if( (char *)dat>=m->m_ext && (char *)dat<(m->m_ext + m->m_size) )
231: return m;
232: } else {
233: if( (char *)dat >= m->m_dat && (char *)dat<(m->m_dat + m->m_size) )
234: return m;
235: }
236: }
1.1.1.3 root 237:
1.1 root 238: DEBUG_ERROR((dfd, "dtom failed"));
1.1.1.3 root 239:
1.1 root 240: return (struct mbuf *)0;
241: }
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.