source/packet.c

   1 /* $Id$
   2
   3 This file is part of gldbg
   4 Copyright © 2010  Mikko Rasa, Mikkosoft Productions
   5 Distributed under the GPL
   6 */
   7
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <sys/uio.h>
  11 #include <unistd.h>
  12 #include "packet.h"
  13 #include "tmpalloc.h"
  14
  15 struct GlOutPacket
  16 {
  17         char *ptr;
  18         unsigned length;
  19         struct iovec *vec;
  20 };
  21
  22 struct GlInPacket
  23 {
  24         const char *ptr;
  25         unsigned length;
  26         unsigned chunk;
  27 };
  28
  29 typedef struct GlOutPacket GlOutPacket;
  30 typedef struct GlInPacket GlInPacket;
  31
  32 struct GlPacket
  33 {
  34         union
  35         {
  36                 GlOutPacket out;
  37                 GlInPacket in;
  38         };
  39 };
  40
  41 // XXX Should make this stuff truly re-entrant
  42 static char *out_buffer = NULL;
  43 static struct iovec *iovecs = NULL;
  44 static GlPacket packet;
  45 static char *in_buffer = NULL;
  46 static unsigned in_fill = 0;
  47 static unsigned in_offset = 0;
  48
  49 static void next_vec(GlPacket *pkt)
  50 {
  51         GlOutPacket *out = &pkt->out;
  52
  53         if(out->ptr!=out->vec->iov_base)
  54         {
  55                 out->vec->iov_len = out->ptr-(char *)out->vec->iov_base;
  56                 out->length += out->vec->iov_len;
  57                 ++out->vec;
  58                 out->vec->iov_base = out->ptr;
  59         }
  60 }
  61
  62 static void reset(GlPacket *pkt)
  63 {
  64         GlOutPacket *out = &pkt->out;
  65
  66         out->ptr = out_buffer;
  67         out->vec = iovecs;
  68         out->vec->iov_base = out->ptr;
  69         out->length = 0;
  70 }
  71
  72 GlPacket *packet_begin(unsigned short func)
  73 {
  74         GlPacket *pkt;
  75
  76         if(!out_buffer)
  77                 out_buffer = (char *)malloc(1024);
  78         if(!iovecs)
  79                 iovecs = (struct iovec *)malloc(16*sizeof(struct iovec));
  80
  81         pkt = &packet;
  82         reset(pkt);
  83
  84         packet_write_int(pkt, 0);
  85         packet_write_short(pkt, func);
  86
  87         return pkt;
  88 }
  89
  90 void packet_send_partial(GlPacket *pkt, int fd)
  91 {
  92         GlOutPacket *out = &pkt->out;
  93
  94         out->length |= 0x80000000;
  95         packet_send(pkt, fd);
  96
  97         reset(pkt);
  98
  99         packet_write_int(pkt, 0);
 100 }
 101
 102 void packet_send(GlPacket *pkt, int fd)
 103 {
 104         GlOutPacket *out = &pkt->out;
 105         struct iovec *v;
 106
 107         next_vec(pkt);
 108         out->ptr = out_buffer;
 109         packet_write_int(pkt, out->length);
 110
 111         for(v=iovecs; v!=out->vec; )
 112         {
 113                 int ret;
 114
 115                 ret = writev(fd, v, out->vec-v);
 116                 if(ret<0)
 117                         return;
 118
 119                 while(v!=out->vec && (unsigned)ret>=v->iov_len)
 120                 {
 121                         ret -= v->iov_len;
 122                         ++v;
 123                 }
 124
 125                 if(v!=out->vec)
 126                 {
 127                         v->iov_base += ret;
 128                         v->iov_len -= ret;
 129                 }
 130         }
 131 }
 132
 133 static void write_raw(GlPacket *pkt, const char *ptr, unsigned size, int byteswap)
 134 {
 135         GlOutPacket *out = &pkt->out;
 136         unsigned i;
 137
 138 #if __BYTE_ORDER == __LITTLE_ENDIAN
 139         if(byteswap)
 140         {
 141                 ptr += size;
 142                 for(i=0; i<size; ++i)
 143                         *out->ptr++ = *--ptr;
 144         }
 145         else
 146 #endif
 147         {
 148                 for(i=0; i<size; ++i)
 149                         *out->ptr++ = *ptr++;
 150         }
 151 }
 152
 153 void packet_write_char(GlPacket *pkt, char v)
 154 {
 155         GlOutPacket *out = &pkt->out;
 156         *out->ptr++ = v;
 157 }
 158
 159 void packet_write_short(GlPacket *pkt, short v)
 160 {
 161         write_raw(pkt, (char *)&v, sizeof(short), 1);
 162 }
 163
 164 void packet_write_int(GlPacket *pkt, int v)
 165 {
 166         write_raw(pkt, (char *)&v, sizeof(int), 1);
 167 }
 168
 169 void packet_write_long(GlPacket *pkt, long v)
 170 {
 171         write_raw(pkt, (char *)&v, sizeof(long), 1);
 172 }
 173
 174 void packet_write_long_long(GlPacket *pkt, long long v)
 175 {
 176         write_raw(pkt, (char *)&v, sizeof(long long), 1);
 177 }
 178
 179 void packet_write_float(GlPacket *pkt, float v)
 180 {
 181         write_raw(pkt, (char *)&v, sizeof(float), 1);
 182 }
 183
 184 void packet_write_double(GlPacket *pkt, double v)
 185 {
 186         write_raw(pkt, (char *)&v, sizeof(double), 1);
 187 }
 188
 189 void packet_write_pointer(GlPacket *pkt, const void *p)
 190 {
 191         write_raw(pkt, (char *)&p, sizeof(void *), 1);
 192 }
 193
 194 void packet_write_data(GlPacket *pkt, const void *data, unsigned size)
 195 {
 196         if(data)
 197         {
 198                 GlOutPacket *out = &pkt->out;
 199
 200                 packet_write_int(pkt, size);
 201                 next_vec(pkt);
 202                 out->vec->iov_base = (void *)data;
 203                 out->vec->iov_len = size;
 204                 out->length += size;
 205                 ++out->vec;
 206                 out->vec->iov_base = out->ptr;
 207         }
 208         else
 209                 packet_write_int(pkt, 0);
 210 }
 211
 212 void packet_write_string(GlPacket *pkt, const char *s)
 213 {
 214         packet_write_data(pkt, s, strlen(s)+1);
 215 }
 216
 217 void packet_write_string_array(GlPacket *pkt, const char **sa, unsigned size)
 218 {
 219         unsigned i;
 220         size /= sizeof(const char *);
 221         packet_write_int(pkt, size);
 222         for(i=0; i<size; ++i)
 223                 packet_write_string(pkt, sa[i]);
 224 }
 225
 226 GlPacket *packet_receive_str(const char *data, unsigned *len)
 227 {
 228         const char *end = data+*len;
 229         GlPacket *pkt;
 230         GlInPacket *in;
 231
 232         if(*len<sizeof(int)+sizeof(short))
 233                 return 0;
 234
 235         pkt = &packet;
 236         in = &pkt->in;
 237         in->ptr = data;
 238         in->chunk = *len;
 239
 240         packet_read_int(pkt, (int *)&in->chunk);
 241
 242         if(in->chunk&0x80000000)
 243         {
 244                 in->chunk &= 0x7FFFFFFF;
 245                 in->length = in->chunk;
 246
 247                 while(1)
 248                 {
 249                         if(end<in->ptr+in->length+sizeof(int))
 250                                 return NULL;
 251
 252                         GlPacket p;
 253                         p.in.ptr = in->ptr+in->length;
 254                         p.in.chunk = p.in.length = end-p.in.ptr;
 255
 256                         unsigned chunk;
 257                         packet_read_int(&p, (int *)&chunk);
 258
 259                         in->length += chunk&0x7FFFFFFF;
 260                         if(!(chunk&0x80000000))
 261                                 break;
 262                 }
 263         }
 264         else
 265                 in->length = in->chunk;
 266
 267         if(end<in->ptr+in->length)
 268                 return NULL;
 269
 270         *len = in->ptr+in->length-data;
 271
 272         return pkt;
 273 }
 274
 275 GlPacket *packet_receive(int fd)
 276 {
 277         int ret;
 278         fd_set fds;
 279         struct timeval tv = { 0, 0 };
 280
 281         FD_ZERO(&fds);
 282         FD_SET(fd, &fds);
 283         ret = select(fd+1, &fds, NULL, NULL, &tv);
 284         if(ret>0)
 285         {
 286                 if(!in_buffer)
 287                         in_buffer = (char *)malloc(1024);
 288
 289                 if(in_offset)
 290                 {
 291                         memmove(in_buffer, in_buffer+in_offset, in_fill-in_offset);
 292                         in_fill -= in_offset;
 293                         in_offset = 0;
 294                 }
 295
 296                 ret = read(fd, in_buffer+in_fill, 1024-in_fill);
 297                 if(ret>0)
 298                         in_fill += ret;
 299         }
 300
 301         if(ret>0 || in_fill>in_offset)
 302         {
 303                 GlPacket *pkt;
 304                 unsigned pkt_length;
 305
 306                 pkt_length = in_fill;
 307                 pkt = packet_receive_str(in_buffer+in_offset, &pkt_length);
 308                 if(pkt)
 309                         in_offset += pkt_length;
 310
 311                 return pkt;
 312         }
 313
 314         return NULL;
 315 }
 316
 317 static void next_chunk(GlPacket *pkt)
 318 {
 319         GlInPacket *in = &pkt->in;
 320
 321         if(in->length==0)
 322                 return;
 323
 324         in->chunk = in->length;
 325         packet_read_int(pkt, (int *)&in->chunk);
 326         in->chunk &= 0x7FFFFFFF;
 327 }
 328
 329 static void read_raw(GlPacket *pkt, char *ptr, unsigned size, int byteswap)
 330 {
 331         GlInPacket *in = &pkt->in;
 332
 333         if(in->chunk==0)
 334                 next_chunk(pkt);
 335
 336         if(in->chunk>=size)
 337         {
 338                 unsigned i;
 339
 340 #if __BYTE_ORDER == __LITTLE_ENDIAN
 341                 if(byteswap)
 342                 {
 343                         ptr += size;
 344                         for(i=0; i<size; ++i)
 345                                 *--ptr = *in->ptr++;
 346                 }
 347                 else
 348 #endif
 349                 {
 350                         for(i=0; i<size; ++i)
 351                                 *ptr++ = *in->ptr++;
 352                 }
 353
 354                 in->length -= size;
 355                 in->chunk -= size;
 356         }
 357         else
 358         {
 359                 memset(ptr, 0, size);
 360                 in->length -= in->chunk;
 361                 in->chunk = 0;
 362         }
 363 }
 364
 365 void packet_read_char(GlPacket *pkt, char *v)
 366 {
 367         read_raw(pkt, v, 1, 0);
 368 }
 369
 370 void packet_read_short(GlPacket *pkt, short *v)
 371 {
 372         read_raw(pkt, (char *)v, sizeof(short), 1);
 373 }
 374
 375 void packet_read_int(GlPacket *pkt, int *v)
 376 {
 377         read_raw(pkt, (char *)v, sizeof(int), 1);
 378 }
 379
 380 void packet_read_long(GlPacket *pkt, long *v)
 381 {
 382         read_raw(pkt, (char *)v, sizeof(long), 1);
 383 }
 384
 385 void packet_read_long_long(GlPacket *pkt, long long *v)
 386 {
 387         read_raw(pkt, (char *)v, sizeof(long long), 1);
 388 }
 389
 390 void packet_read_float(GlPacket *pkt, float *v)
 391 {
 392         read_raw(pkt, (char *)v, sizeof(float), 1);
 393 }
 394
 395 void packet_read_double(GlPacket *pkt, double *v)
 396 {
 397         read_raw(pkt, (char *)v, sizeof(double), 1);
 398 }
 399
 400 void packet_read_pointer(GlPacket *pkt, const void **v)
 401 {
 402         read_raw(pkt, (char *)v, sizeof(const void *), 1);
 403 }
 404
 405 void packet_read_data(GlPacket *pkt, const void **v)
 406 {
 407         GlInPacket *in = &pkt->in;
 408         int vlen;
 409
 410         packet_read_int(pkt, &vlen);
 411         if(vlen)
 412                 *v = in->ptr;
 413         else
 414                 *v = NULL;
 415         in->ptr += vlen;
 416         in->chunk -= vlen;
 417         in->length -= vlen;
 418 }
 419
 420 void packet_read_string(GlPacket *pkt, const char **v)
 421 {
 422         packet_read_data(pkt, (const void **)v);
 423 }
 424
 425 void packet_read_string_array(GlPacket *pkt, const char ***v)
 426 {
 427         int count;
 428         int i;
 429         packet_read_int(pkt, &count);
 430         *v = (const char **)tmpalloc(count*sizeof(const char *));
 431         for(i=0; i<count; ++i)
 432                 packet_read_string(pkt, *v+i);
 433 }