diff options
Diffstat (limited to 'src/data.c')
| -rw-r--r-- | src/data.c | 283 |
1 files changed, 280 insertions, 3 deletions
@@ -28,6 +28,7 @@ #endif #include <errno.h> #include <string.h> +#include <assert.h> #include "gpgme.h" #include "data.h" @@ -36,10 +37,269 @@ #include "priv-io.h" #include "debug.h" + +/* The property table which has an entry for each active data object. + * The data object itself uses an index into this table and the table + * has a pointer back to the data object. All access to that table is + * controlled by the property_table_lock. + * + * We use a separate table instead of linking all data objects + * together for faster locating properties of the data object using + * the data objects serial number. We use 64 bit for the serial + * number which is good enough to create a new data object every + * nanosecond for more than 500 years. Thus no wrap around will ever + * happen. + */ +struct property_s +{ + gpgme_data_t dh; /* The data objcet or NULL if the slot is not used. */ + uint64_t dserial; /* The serial number of the data object. */ + struct { + unsigned int blankout : 1; /* Void the held data. */ + } flags; +}; +typedef struct property_s *property_t; + +static property_t property_table; +static unsigned int property_table_size; +DEFINE_STATIC_LOCK (property_table_lock); + + + +/* Insert the newly created data object DH into the property table and + * store the index of it at R_IDX. An error code is returned on error + * and the table is not changed. */ +static gpg_error_t +insert_into_property_table (gpgme_data_t dh, unsigned int *r_idx) +{ + static uint64_t last_dserial; + gpg_error_t err; + unsigned int idx; + + LOCK (property_table_lock); + if (!property_table) + { + property_table_size = 10; + property_table = calloc (property_table_size, sizeof *property_table); + if (!property_table) + { + err = gpg_error_from_syserror (); + goto leave; + } + } + + /* Find an empty slot. */ + for (idx = 0; idx < property_table_size; idx++) + if (!property_table[idx].dh) + break; + if (!(idx < property_table_size)) + { + /* No empty slot found. Enlarge the table. */ + property_t newtbl; + unsigned int newsize; + + newsize = property_table_size + 10; + if ((newsize * sizeof *property_table) + < (property_table_size * sizeof *property_table)) + { + err = gpg_error (GPG_ERR_ENOMEM); + goto leave; + } + newtbl = realloc (property_table, newsize * sizeof *property_table); + if (!newtbl) + { + err = gpg_error_from_syserror (); + goto leave; + } + property_table = newtbl; + for (idx = property_table_size; idx < newsize; idx++) + property_table[idx].dh = NULL; + idx = property_table_size; + property_table_size = newsize; + } + + /* Slot found. */ + property_table[idx].dh = dh; + property_table[idx].dserial = ++last_dserial; + *r_idx = idx; + err = 0; + + leave: + UNLOCK (property_table_lock); + return err; +} + + +/* Remove the data object at PROPIDX from the table. DH is only used + * for cross checking. */ +static void +remove_from_property_table (gpgme_data_t dh, unsigned int propidx) +{ + LOCK (property_table_lock); + assert (property_table); + assert (propidx < property_table_size); + assert (property_table[propidx].dh == dh); + property_table[propidx].dh = NULL; + UNLOCK (property_table_lock); +} + + +/* Return the data object's serial number for handle DH. This is a + * unique serial number for each created data object. */ +uint64_t +_gpgme_data_get_dserial (gpgme_data_t dh) +{ + uint64_t dserial; + unsigned int idx; + + if (!dh) + return 0; + + idx = dh->propidx; + LOCK (property_table_lock); + assert (property_table); + assert (idx < property_table_size); + assert (property_table[idx].dh == dh); + dserial = property_table[idx].dserial; + UNLOCK (property_table_lock); + + return dserial; +} + + +/* Set an internal property of a data object. The data object may + * either be identified by the usual DH or by using the data serial + * number DSERIAL. */ +gpg_error_t +_gpgme_data_set_prop (gpgme_data_t dh, uint64_t dserial, + data_prop_t name, int value) +{ + gpg_error_t err = 0; + int idx; + TRACE_BEG3 (DEBUG_DATA, "gpgme_data_set_prop", dh, + "dserial=%llu %lu=%d", + (unsigned long long)dserial, + (unsigned long)name, value); + + LOCK (property_table_lock); + if ((!dh && !dserial) || (dh && dserial)) + { + err = gpg_error (GPG_ERR_INV_VALUE); + goto leave; + } + if (dh) /* Lookup via handle. */ + { + idx = dh->propidx; + assert (property_table); + assert (idx < property_table_size); + assert (property_table[idx].dh == dh); + } + else /* Lookup via DSERIAL. */ + { + if (!property_table) + { + err = gpg_error (GPG_ERR_NOT_FOUND); + goto leave; + } + for (idx = 0; idx < property_table_size; idx++) + if (property_table[idx].dh && property_table[idx].dserial == dserial) + break; + if (!(idx < property_table_size)) + { + err = gpg_error (GPG_ERR_NOT_FOUND); + goto leave; + } + } + + switch (name) + { + case DATA_PROP_NONE: /* Nothing to to do. */ + break; + case DATA_PROP_BLANKOUT: + property_table[idx].flags.blankout = !!value; + break; + + default: + err = gpg_error (GPG_ERR_UNKNOWN_NAME); + break; + } + + leave: + UNLOCK (property_table_lock); + return TRACE_ERR (err); +} + + +/* Get an internal property of a data object. This is the counter + * part to _gpgme_data_set_property. The value of the property is + * stored at R_VALUE. On error 0 is stored at R_VALUE. */ +gpg_error_t +_gpgme_data_get_prop (gpgme_data_t dh, uint64_t dserial, + data_prop_t name, int *r_value) +{ + gpg_error_t err = 0; + int idx; + TRACE_BEG2 (DEBUG_DATA, "gpgme_data_get_prop", dh, + "dserial=%llu %lu", + (unsigned long long)dserial, + (unsigned long)name); + + *r_value = 0; + + LOCK (property_table_lock); + if ((!dh && !dserial) || (dh && dserial)) + { + err = gpg_error (GPG_ERR_INV_VALUE); + goto leave; + } + if (dh) /* Lookup via handle. */ + { + idx = dh->propidx; + assert (property_table); + assert (idx < property_table_size); + assert (property_table[idx].dh == dh); + } + else /* Lookup via DSERIAL. */ + { + if (!property_table) + { + err = gpg_error (GPG_ERR_NOT_FOUND); + goto leave; + } + for (idx = 0; idx < property_table_size; idx++) + if (property_table[idx].dh && property_table[idx].dserial == dserial) + break; + if (!(idx < property_table_size)) + { + err = gpg_error (GPG_ERR_NOT_FOUND); + goto leave; + } + } + + switch (name) + { + case DATA_PROP_NONE: /* Nothing to to do. */ + break; + case DATA_PROP_BLANKOUT: + *r_value = property_table[idx].flags.blankout; + break; + + default: + err = gpg_error (GPG_ERR_UNKNOWN_NAME); + break; + } + + leave: + UNLOCK (property_table_lock); + return TRACE_ERR (err); +} + + gpgme_error_t _gpgme_data_new (gpgme_data_t *r_dh, struct _gpgme_data_cbs *cbs) { + gpgme_error_t err; gpgme_data_t dh; if (!r_dh) @@ -56,6 +316,13 @@ _gpgme_data_new (gpgme_data_t *r_dh, struct _gpgme_data_cbs *cbs) dh->cbs = cbs; + err = insert_into_property_table (dh, &dh->propidx); + if (err) + { + free (dh); + return err; + } + *r_dh = dh; return 0; } @@ -67,11 +334,13 @@ _gpgme_data_release (gpgme_data_t dh) if (!dh) return; + remove_from_property_table (dh, dh->propidx); if (dh->file_name) free (dh->file_name); free (dh); } + /* Read up to SIZE bytes into buffer BUFFER from the data object with the handle DH. Return the number of characters read, 0 on EOF and @@ -80,6 +349,7 @@ gpgme_ssize_t gpgme_data_read (gpgme_data_t dh, void *buffer, size_t size) { gpgme_ssize_t res; + int blankout; TRACE_BEG2 (DEBUG_DATA, "gpgme_data_read", dh, "buffer=%p, size=%u", buffer, size); @@ -93,9 +363,16 @@ gpgme_data_read (gpgme_data_t dh, void *buffer, size_t size) gpg_err_set_errno (ENOSYS); return TRACE_SYSRES (-1); } - do - res = (*dh->cbs->read) (dh, buffer, size); - while (res < 0 && errno == EINTR); + + if (_gpgme_data_get_prop (dh, 0, DATA_PROP_BLANKOUT, &blankout) + || blankout) + res = 0; + else + { + do + res = (*dh->cbs->read) (dh, buffer, size); + while (res < 0 && errno == EINTR); + } return TRACE_SYSRES (res); } |