demos/tunala/buffer.c

   1 #include "tunala.h"
   2
   3 #ifndef NO_BUFFER
   4
   5 void buffer_init(buffer_t * buf)
   6 {
   7     buf->used = 0;
   8     buf->total_in = buf->total_out = 0;
   9 }
  10
  11 void buffer_close(buffer_t * buf)
  12 {
  13     /* Our data is static - nothing needs "release", just reset it */
  14     buf->used = 0;
  15 }
  16
  17 /* Code these simple ones in compact form */
  18 unsigned int buffer_used(buffer_t * buf)
  19 {
  20     return buf->used;
  21 }
  22
  23 unsigned int buffer_unused(buffer_t * buf)
  24 {
  25     return (MAX_DATA_SIZE - buf->used);
  26 }
  27
  28 int buffer_full(buffer_t * buf)
  29 {
  30     return (buf->used == MAX_DATA_SIZE ? 1 : 0);
  31 }
  32
  33 int buffer_notfull(buffer_t * buf)
  34 {
  35     return (buf->used < MAX_DATA_SIZE ? 1 : 0);
  36 }
  37
  38 int buffer_empty(buffer_t * buf)
  39 {
  40     return (buf->used == 0 ? 1 : 0);
  41 }
  42
  43 int buffer_notempty(buffer_t * buf)
  44 {
  45     return (buf->used > 0 ? 1 : 0);
  46 }
  47
  48 unsigned long buffer_total_in(buffer_t * buf)
  49 {
  50     return buf->total_in;
  51 }
  52
  53 unsigned long buffer_total_out(buffer_t * buf)
  54 {
  55     return buf->total_out;
  56 }
  57
  58 /*
  59  * These 3 static (internal) functions don't adjust the "total" variables as
  60  * it's not sure when they're called how it should be interpreted. Only the
  61  * higher-level "buffer_[to|from]_[fd|SSL|BIO]" functions should alter these
  62  * values.
  63  */
  64 # if 0                          /* To avoid "unused" warnings */
  65 static unsigned int buffer_adddata(buffer_t * buf, const unsigned char *ptr,
  66                                    unsigned int size)
  67 {
  68     unsigned int added = MAX_DATA_SIZE - buf->used;
  69     if (added > size)
  70         added = size;
  71     if (added == 0)
  72         return 0;
  73     memcpy(buf->data + buf->used, ptr, added);
  74     buf->used += added;
  75     buf->total_in += added;
  76     return added;
  77 }
  78
  79 static unsigned int buffer_tobuffer(buffer_t * to, buffer_t * from, int cap)
  80 {
  81     unsigned int moved, tomove = from->used;
  82     if ((int)tomove > cap)
  83         tomove = cap;
  84     if (tomove == 0)
  85         return 0;
  86     moved = buffer_adddata(to, from->data, tomove);
  87     if (moved == 0)
  88         return 0;
  89     buffer_takedata(from, NULL, moved);
  90     return moved;
  91 }
  92 # endif
  93
  94 static unsigned int buffer_takedata(buffer_t * buf, unsigned char *ptr,
  95                                     unsigned int size)
  96 {
  97     unsigned int taken = buf->used;
  98     if (taken > size)
  99         taken = size;
 100     if (taken == 0)
 101         return 0;
 102     if (ptr)
 103         memcpy(ptr, buf->data, taken);
 104     buf->used -= taken;
 105     /* Do we have to scroll? */
 106     if (buf->used > 0)
 107         memmove(buf->data, buf->data + taken, buf->used);
 108     return taken;
 109 }
 110
 111 # ifndef NO_IP
 112
 113 int buffer_from_fd(buffer_t * buf, int fd)
 114 {
 115     int toread = buffer_unused(buf);
 116     if (toread == 0)
 117         /* Shouldn't be called in this case! */
 118         abort();
 119     toread = read(fd, buf->data + buf->used, toread);
 120     if (toread > 0) {
 121         buf->used += toread;
 122         buf->total_in += toread;
 123     }
 124     return toread;
 125 }
 126
 127 int buffer_to_fd(buffer_t * buf, int fd)
 128 {
 129     int towrite = buffer_used(buf);
 130     if (towrite == 0)
 131         /* Shouldn't be called in this case! */
 132         abort();
 133     towrite = write(fd, buf->data, towrite);
 134     if (towrite > 0) {
 135         buffer_takedata(buf, NULL, towrite);
 136         buf->total_out += towrite;
 137     }
 138     return towrite;
 139 }
 140
 141 # endif                         /* !defined(NO_IP) */
 142
 143 # ifndef NO_OPENSSL
 144
 145 static void int_ssl_check(SSL *s, int ret)
 146 {
 147     int e = SSL_get_error(s, ret);
 148     switch (e) {
 149         /*
 150          * These seem to be harmless and already "dealt with" by our
 151          * non-blocking environment. NB: "ZERO_RETURN" is the clean "error"
 152          * indicating a successfully closed SSL tunnel. We let this happen
 153          * because our IO loop should not appear to have broken on this
 154          * condition - and outside the IO loop, the "shutdown" state is
 155          * checked.
 156          */
 157     case SSL_ERROR_NONE:
 158     case SSL_ERROR_WANT_READ:
 159     case SSL_ERROR_WANT_WRITE:
 160     case SSL_ERROR_WANT_X509_LOOKUP:
 161     case SSL_ERROR_ZERO_RETURN:
 162         return;
 163         /*
 164          * These seem to be indications of a genuine error that should result
 165          * in the SSL tunnel being regarded as "dead".
 166          */
 167     case SSL_ERROR_SYSCALL:
 168     case SSL_ERROR_SSL:
 169         SSL_set_app_data(s, (char *)1);
 170         return;
 171     default:
 172         break;
 173     }
 174     /*
 175      * For any other errors that (a) exist, and (b) crop up - we need to
 176      * interpret what to do with them - so "politely inform" the caller that
 177      * the code needs updating here.
 178      */
 179     abort();
 180 }
 181
 182 void buffer_from_SSL(buffer_t * buf, SSL *ssl)
 183 {
 184     int ret;
 185     if (!ssl || buffer_full(buf))
 186         return;
 187     ret = SSL_read(ssl, buf->data + buf->used, buffer_unused(buf));
 188     if (ret > 0) {
 189         buf->used += ret;
 190         buf->total_in += ret;
 191     }
 192     if (ret < 0)
 193         int_ssl_check(ssl, ret);
 194 }
 195
 196 void buffer_to_SSL(buffer_t * buf, SSL *ssl)
 197 {
 198     int ret;
 199     if (!ssl || buffer_empty(buf))
 200         return;
 201     ret = SSL_write(ssl, buf->data, buf->used);
 202     if (ret > 0) {
 203         buffer_takedata(buf, NULL, ret);
 204         buf->total_out += ret;
 205     }
 206     if (ret < 0)
 207         int_ssl_check(ssl, ret);
 208 }
 209
 210 void buffer_from_BIO(buffer_t * buf, BIO *bio)
 211 {
 212     int ret;
 213     if (!bio || buffer_full(buf))
 214         return;
 215     ret = BIO_read(bio, buf->data + buf->used, buffer_unused(buf));
 216     if (ret > 0) {
 217         buf->used += ret;
 218         buf->total_in += ret;
 219     }
 220 }
 221
 222 void buffer_to_BIO(buffer_t * buf, BIO *bio)
 223 {
 224     int ret;
 225     if (!bio || buffer_empty(buf))
 226         return;
 227     ret = BIO_write(bio, buf->data, buf->used);
 228     if (ret > 0) {
 229         buffer_takedata(buf, NULL, ret);
 230         buf->total_out += ret;
 231     }
 232 }
 233
 234 # endif                         /* !defined(NO_OPENSSL) */
 235
 236 #endif                          /* !defined(NO_BUFFER) */