#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <sys/mman.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
off_t description;
// ASes in the database
- struct loc_as** as;
+ struct loc_database_as_v0* as_v0;
size_t as_count;
struct loc_stringpool* pool;
};
-LOC_EXPORT int loc_database_new(struct loc_ctx* ctx, struct loc_database** database, size_t pool_size) {
- struct loc_database* db = calloc(1, sizeof(*db));
- if (!db)
- return -ENOMEM;
-
- // Reference context
- db->ctx = loc_ref(ctx);
- db->refcount = 1;
-
- // Save creation time
- db->created_at = time(NULL);
-
- DEBUG(db->ctx, "Database allocated at %p\n", db);
-
- // Create string pool
- int r = loc_stringpool_new(db->ctx, &db->pool, pool_size);
- if (r) {
- loc_database_unref(db);
- return r;
- }
-
- *database = db;
-
- return 0;
-}
-
-LOC_EXPORT int loc_database_open(struct loc_ctx* ctx, struct loc_database** database, FILE* f) {
- int r = loc_database_new(ctx, database, 0);
- if (r)
- return r;
-
- return loc_database_read(*database, f);
-}
-
-LOC_EXPORT struct loc_database* loc_database_ref(struct loc_database* db) {
- db->refcount++;
-
- return db;
-}
-
-static void loc_database_free(struct loc_database* db) {
- DEBUG(db->ctx, "Releasing database %p\n", db);
-
- // Remove references to all ASes
- if (db->as) {
- for (unsigned int i = 0; i < db->as_count; i++) {
- loc_as_unref(db->as[i]);
- }
- free(db->as);
- }
-
- loc_stringpool_unref(db->pool);
-
- // Close file
- if (db->file)
- fclose(db->file);
-
- loc_unref(db->ctx);
- free(db);
-}
-
-LOC_EXPORT struct loc_database* loc_database_unref(struct loc_database* db) {
- if (--db->refcount > 0)
- return NULL;
-
- loc_database_free(db);
- return NULL;
-}
-
-LOC_EXPORT time_t loc_database_created_at(struct loc_database* db) {
- return db->created_at;
-}
-
-LOC_EXPORT const char* loc_database_get_vendor(struct loc_database* db) {
- return loc_stringpool_get(db->pool, db->vendor);
-}
-
-LOC_EXPORT int loc_database_set_vendor(struct loc_database* db, const char* vendor) {
- // Add the string to the string pool
- off_t offset = loc_stringpool_add(db->pool, vendor);
- if (offset < 0)
- return offset;
-
- db->vendor = offset;
- return 0;
-}
-
-LOC_EXPORT const char* loc_database_get_description(struct loc_database* db) {
- return loc_stringpool_get(db->pool, db->description);
-}
-
-LOC_EXPORT int loc_database_set_description(struct loc_database* db, const char* description) {
- // Add the string to the string pool
- off_t offset = loc_stringpool_add(db->pool, description);
- if (offset < 0)
- return offset;
-
- db->description = offset;
- return 0;
-}
-
-LOC_EXPORT size_t loc_database_count_as(struct loc_database* db) {
- return db->as_count;
-}
-
-static int loc_database_has_as(struct loc_database* db, struct loc_as* as) {
- for (unsigned int i = 0; i < db->as_count; i++) {
- if (loc_as_cmp(as, db->as[i]) == 0)
- return i;
- }
-
- return -1;
-}
-
-static int __loc_as_cmp(const void* as1, const void* as2) {
- return loc_as_cmp(*(struct loc_as**)as1, *(struct loc_as**)as2);
-}
-
-static void loc_database_sort_ases(struct loc_database* db) {
- qsort(db->as, db->as_count, sizeof(*db->as), __loc_as_cmp);
-}
-
-static struct loc_as* __loc_database_add_as(struct loc_database* db, struct loc_as* as) {
- // Check if AS exists already
- int i = loc_database_has_as(db, as);
- if (i >= 0) {
- loc_as_unref(as);
-
- // Select already existing AS
- as = db->as[i];
-
- return loc_as_ref(as);
- }
-
- db->as_count++;
-
- // Make space for the new entry
- db->as = realloc(db->as, sizeof(*db->as) * db->as_count);
-
- // Add the new entry at the end
- db->as[db->as_count - 1] = loc_as_ref(as);
-
- // Sort everything
- loc_database_sort_ases(db);
-
- return as;
-}
-
-LOC_EXPORT struct loc_as* loc_database_add_as(struct loc_database* db, uint32_t number) {
- struct loc_as* as;
- int r = loc_as_new(db->ctx, db->pool, &as, number);
- if (r)
- return NULL;
-
- return __loc_database_add_as(db, as);
-}
-
static int loc_database_read_magic(struct loc_database* db) {
struct loc_database_magic magic;
static int loc_database_read_as_section_v0(struct loc_database* db,
off_t as_offset, size_t as_length) {
- struct loc_database_as_v0 dbobj;
+ DEBUG(db->ctx, "Reading AS section from %jd (%zu bytes)\n", as_offset, as_length);
- // Read from the start of the section
- int r = fseek(db->file, as_offset, SEEK_SET);
- if (r)
- return r;
-
- // Read all ASes
- size_t as_count = as_length / sizeof(dbobj);
- for (unsigned int i = 0; i < as_count; i++) {
- size_t bytes_read = fread(&dbobj, 1, sizeof(dbobj), db->file);
- if (bytes_read < sizeof(dbobj)) {
- ERROR(db->ctx, "Could not read an AS object\n");
- return -ENOMSG;
- }
-
- // Allocate a new AS
- struct loc_as* as;
- r = loc_as_new_from_database_v0(db->ctx, db->pool, &as, &dbobj);
- if (r)
- return r;
+ if (as_length > 0) {
+ db->as_v0 = mmap(NULL, as_length, PROT_READ,
+ MAP_SHARED, fileno(db->file), as_offset);
- // Attach it to the database
- as = __loc_database_add_as(db, as);
- loc_as_unref(as);
+ if (db->as_v0 == MAP_FAILED)
+ return -errno;
}
+ db->as_count = as_length / sizeof(*db->as_v0);
+
INFO(db->ctx, "Read %zu ASes from the database\n", db->as_count);
return 0;
off_t pool_offset = ntohl(header.pool_offset);
size_t pool_length = ntohl(header.pool_length);
- int r = loc_stringpool_read(db->pool, db->file, pool_offset, pool_length);
+ int r = loc_stringpool_new(db->ctx, &db->pool, 0);
+ if (r)
+ return r;
+
+ r = loc_stringpool_read(db->pool, db->file, pool_offset, pool_length);
if (r)
return r;
}
}
-LOC_EXPORT int loc_database_read(struct loc_database* db, FILE* f) {
- // Copy the file pointer and work on that so we don't care if
- // the calling function closes the file
+static FILE* copy_file_pointer(FILE* f) {
int fd = fileno(f);
// Make a copy
fd = dup(fd);
- // Retrieve a file pointer
- db->file = fdopen(fd, "r");
- if (!db->file)
- return -errno;
+ return fdopen(fd, "r");
+}
- int r = fseek(db->file, 0, SEEK_SET);
- if (r)
- return r;
+LOC_EXPORT int loc_database_new(struct loc_ctx* ctx, struct loc_database** database, FILE* f) {
+ struct loc_database* db = calloc(1, sizeof(*db));
+ if (!db)
+ return -ENOMEM;
+
+ // Reference context
+ db->ctx = loc_ref(ctx);
+ db->refcount = 1;
+
+ DEBUG(db->ctx, "Database object allocated at %p\n", db);
+
+ // Copy the file pointer and work on that so we don't care if
+ // the calling function closes the file
+ db->file = copy_file_pointer(f);
+ if (!db->file)
+ goto FAIL;
// Read magic bytes
- r = loc_database_read_magic(db);
+ int r = loc_database_read_magic(db);
if (r)
return r;
if (r)
return r;
+ *database = db;
+
return 0;
-}
-static void loc_database_make_magic(struct loc_database* db, struct loc_database_magic* magic) {
- // Copy magic bytes
- for (unsigned int i = 0; i < strlen(LOC_DATABASE_MAGIC); i++)
- magic->magic[i] = LOC_DATABASE_MAGIC[i];
+FAIL:
+ loc_database_unref(db);
- // Set version
- magic->version = htons(LOC_DATABASE_VERSION);
+ return -errno;
}
-static void loc_database_align_page_boundary(off_t* offset, FILE* f) {
- // Move to next page boundary
- while (*offset % LOC_DATABASE_PAGE_SIZE > 0)
- *offset += fwrite("", 1, 1, f);
+LOC_EXPORT struct loc_database* loc_database_ref(struct loc_database* db) {
+ db->refcount++;
+
+ return db;
}
-static int loc_database_write_pool(struct loc_database* db, struct loc_database_header_v0* header, off_t* offset, FILE* f) {
- // Save the offset of the pool section
- DEBUG(db->ctx, "Pool starts at %jd bytes\n", *offset);
- header->pool_offset = htonl(*offset);
+static void loc_database_free(struct loc_database* db) {
+ DEBUG(db->ctx, "Releasing database %p\n", db);
- // Write the pool
- size_t pool_length = loc_stringpool_write(db->pool, f);
- *offset += pool_length;
+ // Removing all ASes
+ if (db->as_v0) {
+ int r = munmap(db->as_v0, db->as_count * sizeof(*db->as_v0));
+ if (r)
+ ERROR(db->ctx, "Could not unmap AS section: %s\n", strerror(errno));
+ }
- DEBUG(db->ctx, "Pool has a length of %zu bytes\n", pool_length);
- header->pool_length = htonl(pool_length);
+ loc_stringpool_unref(db->pool);
- return 0;
+ // Close file
+ if (db->file)
+ fclose(db->file);
+
+ loc_unref(db->ctx);
+ free(db);
}
-static int loc_database_write_as_section(struct loc_database* db,
- struct loc_database_header_v0* header, off_t* offset, FILE* f) {
- DEBUG(db->ctx, "AS section starts at %jd bytes\n", *offset);
- header->as_offset = htonl(*offset);
+LOC_EXPORT struct loc_database* loc_database_unref(struct loc_database* db) {
+ if (--db->refcount > 0)
+ return NULL;
- size_t as_length = 0;
+ loc_database_free(db);
+ return NULL;
+}
- struct loc_database_as_v0 dbas;
- for (unsigned int i = 0; i < db->as_count; i++) {
- // Convert AS into database format
- loc_as_to_database_v0(db->as[i], &dbas);
+LOC_EXPORT time_t loc_database_created_at(struct loc_database* db) {
+ return db->created_at;
+}
- // Write to disk
- offset += fwrite(&dbas, 1, sizeof(dbas), f);
- as_length += sizeof(dbas);
- }
+LOC_EXPORT const char* loc_database_get_vendor(struct loc_database* db) {
+ return loc_stringpool_get(db->pool, db->vendor);
+}
- DEBUG(db->ctx, "AS section has a length of %zu bytes\n", as_length);
- header->as_length = htonl(as_length);
+LOC_EXPORT const char* loc_database_get_description(struct loc_database* db) {
+ return loc_stringpool_get(db->pool, db->description);
+}
- return 0;
+LOC_EXPORT size_t loc_database_count_as(struct loc_database* db) {
+ return db->as_count;
}
-LOC_EXPORT int loc_database_write(struct loc_database* db, FILE* f) {
- struct loc_database_magic magic;
- loc_database_make_magic(db, &magic);
+// Returns the AS at position pos
+static int loc_database_fetch_as(struct loc_database* db, struct loc_as** as, off_t pos) {
+ if ((size_t)pos >= db->as_count)
+ return -EINVAL;
- // Make the header
- struct loc_database_header_v0 header;
- header.created_at = htobe64(db->created_at);
- header.vendor = htonl(db->vendor);
- header.description = htonl(db->description);
+ DEBUG(db->ctx, "Fetching AS at position %jd\n", pos);
int r;
- off_t offset = 0;
-
- // Start writing at the beginning of the file
- r = fseek(f, 0, SEEK_SET);
- if (r)
- return r;
+ switch (db->version) {
+ case 0:
+ r = loc_as_new_from_database_v0(db->ctx, db->pool, as, db->as_v0 + pos);
+ break;
- // Write the magic
- offset += fwrite(&magic, 1, sizeof(magic), f);
+ default:
+ return -1;
+ }
- // Skip the space we need to write the header later
- r = fseek(f, sizeof(header), SEEK_CUR);
- if (r) {
- DEBUG(db->ctx, "Could not seek to position after header\n");
- return r;
+ if (r == 0) {
+ DEBUG(db->ctx, "Got AS%u\n", loc_as_get_number(*as));
}
- offset += sizeof(header);
- loc_database_align_page_boundary(&offset, f);
+ return r;
+}
- // Write all ASes
- r = loc_database_write_as_section(db, &header, &offset, f);
- if (r)
- return r;
+// Performs a binary search to find the AS in the list
+LOC_EXPORT int loc_database_get_as(struct loc_database* db, struct loc_as** as, uint32_t number) {
+ off_t lo = 0;
+ off_t hi = db->as_count - 1;
- loc_database_align_page_boundary(&offset, f);
+ while (lo <= hi) {
+ off_t i = (lo + hi) / 2;
- // Write pool
- r = loc_database_write_pool(db, &header, &offset, f);
- if (r)
- return r;
+ // Fetch AS in the middle between lo and hi
+ int r = loc_database_fetch_as(db, as, i);
+ if (r)
+ return r;
- // Write the header
- r = fseek(f, sizeof(magic), SEEK_SET);
- if (r)
- return r;
+ // Check if this is a match
+ uint32_t as_number = loc_as_get_number(*as);
+ if (as_number == number)
+ return 0;
+
+ // If it wasn't, we release the AS and
+ // adjust our search pointers
+ loc_as_unref(*as);
+
+ if (as_number < number) {
+ lo = i + 1;
+ } else
+ hi = i - 1;
+ }
- offset += fwrite(&header, 1, sizeof(header), f);
+ // Nothing found
+ *as = NULL;
return 0;
}