| 1 | /* uipc_mbuf.c 1.29 82/02/08 */ |
| 2 | |
| 3 | #include "../h/param.h" |
| 4 | #include "../h/dir.h" |
| 5 | #include "../h/user.h" |
| 6 | #include "../h/proc.h" |
| 7 | #include "../h/pte.h" |
| 8 | #include "../h/cmap.h" |
| 9 | #include "../h/map.h" |
| 10 | #include "../h/mbuf.h" |
| 11 | #include "../net/in_systm.h" /* XXX */ |
| 12 | #include "../h/vm.h" |
| 13 | |
| 14 | mbinit() |
| 15 | { |
| 16 | |
| 17 | COUNT(MBINIT); |
| 18 | if (m_reserve(32) == 0) |
| 19 | goto bad; |
| 20 | if (m_clalloc(4, MPG_MBUFS) == 0) |
| 21 | goto bad; |
| 22 | if (m_clalloc(32, MPG_CLUSTERS) == 0) |
| 23 | goto bad; |
| 24 | return; |
| 25 | bad: |
| 26 | panic("mbinit"); |
| 27 | } |
| 28 | |
| 29 | caddr_t |
| 30 | m_clalloc(ncl, how) |
| 31 | register int ncl; |
| 32 | int how; |
| 33 | { |
| 34 | int npg, mbx; |
| 35 | register struct mbuf *m; |
| 36 | register int i; |
| 37 | int s; |
| 38 | |
| 39 | COUNT(M_CLALLOC); |
| 40 | npg = ncl * CLSIZE; |
| 41 | s = splimp(); /* careful: rmalloc isn't reentrant */ |
| 42 | mbx = rmalloc(mbmap, npg); |
| 43 | splx(s); |
| 44 | if (mbx == 0) |
| 45 | return (0); |
| 46 | m = cltom(mbx / CLSIZE); |
| 47 | if (memall(&Mbmap[mbx], ncl * CLSIZE, proc, CSYS) == 0) |
| 48 | return (0); |
| 49 | vmaccess(&Mbmap[mbx], (caddr_t)m, npg); |
| 50 | switch (how) { |
| 51 | |
| 52 | case MPG_CLUSTERS: |
| 53 | s = splimp(); |
| 54 | for (i = 0; i < ncl; i++) { |
| 55 | m->m_off = 0; |
| 56 | m->m_next = mclfree; |
| 57 | mclfree = m; |
| 58 | m += CLBYTES / sizeof (*m); |
| 59 | nmclfree++; |
| 60 | } |
| 61 | mbstat.m_clusters += ncl; |
| 62 | splx(s); |
| 63 | break; |
| 64 | |
| 65 | case MPG_MBUFS: |
| 66 | for (i = ncl * CLBYTES / sizeof (*m); i > 0; i--) { |
| 67 | m->m_off = 0; |
| 68 | m->m_free = 0; |
| 69 | (void) m_free(m); |
| 70 | m++; |
| 71 | } |
| 72 | mbstat.m_clusters += ncl; |
| 73 | break; |
| 74 | } |
| 75 | return ((caddr_t)m); |
| 76 | } |
| 77 | |
| 78 | m_pgfree(addr, n) |
| 79 | caddr_t addr; |
| 80 | int n; |
| 81 | { |
| 82 | |
| 83 | COUNT(M_PGFREE); |
| 84 | } |
| 85 | |
| 86 | m_expand() |
| 87 | { |
| 88 | |
| 89 | COUNT(M_EXPAND); |
| 90 | if (mbstat.m_bufs >= mbstat.m_hiwat) |
| 91 | return (0); |
| 92 | if (m_clalloc(1, MPG_MBUFS) == 0) |
| 93 | goto steal; |
| 94 | return (1); |
| 95 | steal: |
| 96 | /* should ask protocols to free code */ |
| 97 | return (0); |
| 98 | } |
| 99 | |
| 100 | /* NEED SOME WAY TO RELEASE SPACE */ |
| 101 | |
| 102 | /* |
| 103 | * Space reservation routines |
| 104 | */ |
| 105 | m_reserve(mbufs) |
| 106 | int mbufs; |
| 107 | { |
| 108 | |
| 109 | if (mbstat.m_lowat + (mbufs>>1) > (NMBCLUSTERS-32) * CLBYTES) |
| 110 | return (0); |
| 111 | mbstat.m_hiwat += mbufs; |
| 112 | mbstat.m_lowat = mbstat.m_hiwat >> 1; |
| 113 | return (1); |
| 114 | } |
| 115 | |
| 116 | m_release(mbufs) |
| 117 | int mbufs; |
| 118 | { |
| 119 | |
| 120 | mbstat.m_hiwat -= mbufs; |
| 121 | mbstat.m_lowat = mbstat.m_hiwat >> 1; |
| 122 | } |
| 123 | |
| 124 | /* |
| 125 | * Space allocation routines. |
| 126 | * These are also available as macros |
| 127 | * for critical paths. |
| 128 | */ |
| 129 | struct mbuf * |
| 130 | m_get(canwait) |
| 131 | int canwait; |
| 132 | { |
| 133 | register struct mbuf *m; |
| 134 | |
| 135 | COUNT(M_GET); |
| 136 | MGET(m, canwait); |
| 137 | return (m); |
| 138 | } |
| 139 | |
| 140 | struct mbuf * |
| 141 | m_getclr(canwait) |
| 142 | int canwait; |
| 143 | { |
| 144 | register struct mbuf *m; |
| 145 | |
| 146 | COUNT(M_GETCLR); |
| 147 | m = m_get(canwait); |
| 148 | if (m == 0) |
| 149 | return (0); |
| 150 | m->m_off = MMINOFF; |
| 151 | bzero(mtod(m, caddr_t), MLEN); |
| 152 | return (m); |
| 153 | } |
| 154 | |
| 155 | struct mbuf * |
| 156 | m_free(m) |
| 157 | struct mbuf *m; |
| 158 | { |
| 159 | register struct mbuf *n; |
| 160 | |
| 161 | COUNT(M_FREE); |
| 162 | MFREE(m, n); |
| 163 | return (n); |
| 164 | } |
| 165 | |
| 166 | /*ARGSUSED*/ |
| 167 | struct mbuf * |
| 168 | m_more(type) |
| 169 | int type; |
| 170 | { |
| 171 | register struct mbuf *m; |
| 172 | |
| 173 | COUNT(M_MORE); |
| 174 | if (!m_expand()) { |
| 175 | mbstat.m_drops++; |
| 176 | return (NULL); |
| 177 | } |
| 178 | #define m_more(x) (panic("m_more"), (struct mbuf *)0) |
| 179 | MGET(m, type); |
| 180 | #undef m_more |
| 181 | return (m); |
| 182 | } |
| 183 | |
| 184 | m_freem(m) |
| 185 | register struct mbuf *m; |
| 186 | { |
| 187 | register struct mbuf *n; |
| 188 | register int s; |
| 189 | |
| 190 | COUNT(M_FREEM); |
| 191 | if (m == NULL) |
| 192 | return; |
| 193 | s = splimp(); |
| 194 | do { |
| 195 | MFREE(m, n); |
| 196 | } while (m = n); |
| 197 | splx(s); |
| 198 | } |
| 199 | |
| 200 | /* |
| 201 | * Mbuffer utility routines. |
| 202 | */ |
| 203 | struct mbuf * |
| 204 | m_copy(m, off, len) |
| 205 | register struct mbuf *m; |
| 206 | int off; |
| 207 | register int len; |
| 208 | { |
| 209 | register struct mbuf *n, **np; |
| 210 | struct mbuf *top, *p; |
| 211 | COUNT(M_COPY); |
| 212 | |
| 213 | if (len == 0) |
| 214 | return (0); |
| 215 | if (off < 0 || len < 0) |
| 216 | panic("m_copy"); |
| 217 | while (off > 0) { |
| 218 | if (m == 0) |
| 219 | panic("m_copy"); |
| 220 | if (off < m->m_len) |
| 221 | break; |
| 222 | off -= m->m_len; |
| 223 | m = m->m_next; |
| 224 | } |
| 225 | np = ⊤ |
| 226 | top = 0; |
| 227 | while (len > 0) { |
| 228 | if (m == 0) { |
| 229 | if (len != M_COPYALL) |
| 230 | panic("m_copy"); |
| 231 | break; |
| 232 | } |
| 233 | MGET(n, 1); |
| 234 | *np = n; |
| 235 | if (n == 0) |
| 236 | goto nospace; |
| 237 | n->m_len = MIN(len, m->m_len - off); |
| 238 | if (m->m_off > MMAXOFF) { |
| 239 | p = mtod(m, struct mbuf *); |
| 240 | n->m_off = ((int)p - (int)n) + off; |
| 241 | mclrefcnt[mtocl(p)]++; |
| 242 | } else { |
| 243 | n->m_off = MMINOFF; |
| 244 | bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t), |
| 245 | (unsigned)n->m_len); |
| 246 | } |
| 247 | if (len != M_COPYALL) |
| 248 | len -= n->m_len; |
| 249 | off = 0; |
| 250 | m = m->m_next; |
| 251 | np = &n->m_next; |
| 252 | } |
| 253 | return (top); |
| 254 | nospace: |
| 255 | m_freem(top); |
| 256 | return (0); |
| 257 | } |
| 258 | |
| 259 | m_cat(m, n) |
| 260 | register struct mbuf *m, *n; |
| 261 | { |
| 262 | |
| 263 | while (m->m_next) |
| 264 | m = m->m_next; |
| 265 | while (n) |
| 266 | if (m->m_off < MMAXOFF && |
| 267 | m->m_off + m->m_len + n->m_len <= MMAXOFF) { |
| 268 | bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len, |
| 269 | (u_int)n->m_len); |
| 270 | m->m_len += n->m_len; |
| 271 | n = m_free(n); |
| 272 | } else { |
| 273 | m->m_next = n; |
| 274 | m = n; |
| 275 | n = m->m_next; |
| 276 | } |
| 277 | } |
| 278 | |
| 279 | m_adj(mp, len) |
| 280 | struct mbuf *mp; |
| 281 | register int len; |
| 282 | { |
| 283 | register struct mbuf *m, *n; |
| 284 | |
| 285 | COUNT(M_ADJ); |
| 286 | if ((m = mp) == NULL) |
| 287 | return; |
| 288 | if (len >= 0) { |
| 289 | while (m != NULL && len > 0) { |
| 290 | if (m->m_len <= len) { |
| 291 | len -= m->m_len; |
| 292 | m->m_len = 0; |
| 293 | m = m->m_next; |
| 294 | } else { |
| 295 | m->m_len -= len; |
| 296 | m->m_off += len; |
| 297 | break; |
| 298 | } |
| 299 | } |
| 300 | } else { |
| 301 | /* a 2 pass algorithm might be better */ |
| 302 | len = -len; |
| 303 | while (len > 0 && m->m_len != 0) { |
| 304 | while (m != NULL && m->m_len != 0) { |
| 305 | n = m; |
| 306 | m = m->m_next; |
| 307 | } |
| 308 | if (n->m_len <= len) { |
| 309 | len -= n->m_len; |
| 310 | n->m_len = 0; |
| 311 | m = mp; |
| 312 | } else { |
| 313 | n->m_len -= len; |
| 314 | break; |
| 315 | } |
| 316 | } |
| 317 | } |
| 318 | } |
| 319 | |
| 320 | struct mbuf * |
| 321 | m_pullup(m0, len) |
| 322 | struct mbuf *m0; |
| 323 | int len; |
| 324 | { |
| 325 | register struct mbuf *m, *n; |
| 326 | int cnt; |
| 327 | |
| 328 | n = m0; |
| 329 | if (len > MLEN) |
| 330 | goto bad; |
| 331 | MGET(m, 0); |
| 332 | if (m == 0) |
| 333 | goto bad; |
| 334 | m->m_off = MMINOFF; |
| 335 | m->m_len = 0; |
| 336 | do { |
| 337 | cnt = MIN(MLEN - m->m_len, len); |
| 338 | if (cnt > n->m_len) |
| 339 | cnt = n->m_len; |
| 340 | bcopy(mtod(n, caddr_t), mtod(m, caddr_t)+m->m_len, cnt); |
| 341 | len -= cnt; |
| 342 | m->m_len += cnt; |
| 343 | n->m_off += cnt; |
| 344 | n->m_len -= cnt; |
| 345 | if (n->m_len) |
| 346 | break; |
| 347 | n = m_free(n); |
| 348 | } while (n); |
| 349 | if (len) { |
| 350 | (void) m_free(m); |
| 351 | goto bad; |
| 352 | } |
| 353 | m->m_next = n; |
| 354 | return (m); |
| 355 | bad: |
| 356 | m_freem(n); |
| 357 | return (0); |
| 358 | } |