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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 00:53:35 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 00:53:35 +0000 |
commit | 69c6a41ffb878ef98c9378ed4b1634a404cfaa7f (patch) | |
tree | b2a4f704565d62fbb129ab9dc3b35977c50e6e7f /src/libzscanner/scanner.rl | |
parent | Initial commit. (diff) | |
download | knot-upstream.tar.xz knot-upstream.zip |
Adding upstream version 2.7.6.upstream/2.7.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/libzscanner/scanner.rl')
-rw-r--r-- | src/libzscanner/scanner.rl | 541 |
1 files changed, 541 insertions, 0 deletions
diff --git a/src/libzscanner/scanner.rl b/src/libzscanner/scanner.rl new file mode 100644 index 0000000..4050b56 --- /dev/null +++ b/src/libzscanner/scanner.rl @@ -0,0 +1,541 @@ +/* Copyright (C) 2018 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <arpa/inet.h> +#include <fcntl.h> +#include <stdbool.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <libgen.h> +#include <math.h> +#include <netinet/in.h> +#include <sys/socket.h> +#include <sys/mman.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> + +#include "libzscanner/scanner.h" +#include "libzscanner/functions.h" +#include "libknot/descriptor.h" + +/*! \brief Maximal length of rdata item. */ +#define MAX_ITEM_LENGTH 255 + +/*! \brief Latitude value for equator (2^31). */ +#define LOC_LAT_ZERO (uint32_t)2147483648 +/*! \brief Longitude value for meridian (2^31). */ +#define LOC_LONG_ZERO (uint32_t)2147483648 +/*! \brief Zero level altitude value. */ +#define LOC_ALT_ZERO (uint32_t)10000000 + +/*! \brief Shorthand for setting warning data. */ +#define WARN(err_code) { s->error.code = err_code; } +/*! \brief Shorthand for setting error data. */ +#define ERR(err_code) { WARN(err_code); s->error.fatal = true; } +/*! \brief Shorthand for error reset. */ +#define NOERR { WARN(ZS_OK); s->error.fatal = false; } + +/*! + * \brief Writes record type number to r_data. + * + * \param type Type number. + * \param rdata_tail Position where to write type number to. + */ +static inline void type_num(const uint16_t type, uint8_t **rdata_tail) +{ + *((uint16_t *)*rdata_tail) = htons(type); + *rdata_tail += 2; +} + +/*! + * \brief Sets bit to bitmap window. + * + * \param type Type number. + * \param s Scanner context. + */ +static inline void window_add_bit(const uint16_t type, zs_scanner_t *s) { + uint8_t win = type / 256; + uint8_t bit_pos = type % 256; + uint8_t byte_pos = bit_pos / 8; + + ((s->windows[win]).bitmap)[byte_pos] |= 128 >> (bit_pos % 8); + + if ((s->windows[win]).length < byte_pos + 1) { + (s->windows[win]).length = byte_pos + 1; + } + + if (s->last_window < win) { + s->last_window = win; + } +} + +// Include scanner file (in Ragel). +%%{ + machine zone_scanner; + + include "scanner_body.rl"; + + write data; +}%% + +__attribute__((visibility("default"))) +int zs_init( + zs_scanner_t *s, + const char *origin, + const uint16_t rclass, + const uint32_t ttl) +{ + if (s == NULL) { + return -1; + } + + memset(s, 0, sizeof(*s)); + + // Nonzero initial scanner state. + s->cs = %%{ write start; }%%; + + // Reset the file descriptor. + s->file.descriptor = -1; + + // Use the root zone as origin if not specified. + if (origin == NULL || strlen(origin) == 0) { + origin = "."; + } + size_t origin_len = strlen(origin); + + // Prepare a zone settings header. + const char *format; + if (origin[origin_len - 1] != '.') { + format = "$ORIGIN %s.\n"; + } else { + format = "$ORIGIN %s\n"; + } + + char settings[1024]; + int ret = snprintf(settings, sizeof(settings), format, origin); + if (ret <= 0 || ret >= sizeof(settings)) { + ERR(ZS_ENOMEM); + return -1; + } + + // Parse the settings to set up the scanner origin. + if (zs_set_input_string(s, settings, ret) != 0 || + zs_parse_all(s) != 0) { + return -1; + } + + // Set scanner defaults. + s->path = strdup("."); + if (s->path == NULL) { + ERR(ZS_ENOMEM); + return -1; + } + s->default_class = rclass; + s->default_ttl = ttl; + s->line_counter = 1; + + s->state = ZS_STATE_NONE; + s->process.automatic = false; + + return 0; +} + +static void input_deinit( + zs_scanner_t *s, + bool keep_filename) +{ + // Deinit the file input. + if (s->file.descriptor != -1) { + // Unmap the file content. + if (s->input.start != NULL) { + if (s->input.mmaped) { + munmap((void *)s->input.start, + s->input.end - s->input.start); + } else { + free((void *)s->input.start); + } + } + + // Close the opened file. + close(s->file.descriptor); + s->file.descriptor = -1; + } + + // Keep file name for possible trailing error report. + if (!keep_filename) { + free(s->file.name); + s->file.name = NULL; + } + + // Unset the input limits. + s->input.start = NULL; + s->input.current = NULL; + s->input.end = NULL; + s->input.eof = false; +} + +__attribute__((visibility("default"))) +void zs_deinit( + zs_scanner_t *s) +{ + if (s == NULL) { + return; + } + + input_deinit(s, false); + free(s->path); +} + +static int set_input_string( + zs_scanner_t *s, + const char *input, + size_t size, + bool final_block) +{ + if (s == NULL) { + return -1; + } + + if (input == NULL) { + ERR(ZS_EINVAL); + return -1; + } + + // Deinit possibly opened file. + input_deinit(s, final_block); + + // Set the scanner input limits. + s->input.start = input; + s->input.current = input; + s->input.end = input + size; + s->input.eof = final_block; + + return 0; +} + +static char *read_file_to_buf( + int fd, + size_t *bufsize) +{ + size_t bufs = 0, newbufs = 8192; + char *buf = malloc(bufs + newbufs); + int ret = 0; + + while (buf != NULL && (ret = read(fd, buf + bufs, newbufs)) == newbufs) { + bufs += newbufs; + newbufs = bufs; + char *newbuf = realloc(buf, bufs + newbufs); + if (newbuf == NULL) { + free(buf); + } + buf = newbuf; + } + if (ret < 0) { + free(buf); + return NULL; + } + + *bufsize = bufs + ret; + return buf; +} + +__attribute__((visibility("default"))) +int zs_set_input_string( + zs_scanner_t *s, + const char *input, + size_t size) +{ + s->state = ZS_STATE_NONE; + + return set_input_string(s, input, size, false); +} + +__attribute__((visibility("default"))) +int zs_set_input_file( + zs_scanner_t *s, + const char *file_name) +{ + if (s == NULL) { + return -1; + } + + if (file_name == NULL) { + ERR(ZS_EINVAL); + return -1; + } + + // Deinit possibly opened file. + input_deinit(s, false); + + // Try to open the file. + s->file.descriptor = open(file_name, O_RDONLY); + if (s->file.descriptor == -1) { + ERR(ZS_FILE_OPEN); + return -1; + } + + char *start = NULL; + size_t size = 0; + + // Check the input. + struct stat file_stat; + if (fstat(s->file.descriptor, &file_stat) == -1) { + ERR(ZS_FILE_INVALID); + input_deinit(s, false); + return -1; + } else if (S_ISCHR(file_stat.st_mode) || + S_ISBLK(file_stat.st_mode) || + S_ISFIFO(file_stat.st_mode)) { + // Workaround if cannot mmap, read to memory. + start = read_file_to_buf(s->file.descriptor, &size); + if (start == NULL) { + ERR(ZS_FILE_INVALID); + input_deinit(s, false); + return -1; + } + } else if (!S_ISREG(file_stat.st_mode)) { // Require regular file. + ERR(ZS_FILE_INVALID); + input_deinit(s, false); + return -1; + } else if (file_stat.st_size > 0) { // Mmap non-emtpy file. + start = mmap(0, file_stat.st_size, PROT_READ, MAP_SHARED, + s->file.descriptor, 0); + if (start == MAP_FAILED) { + ERR(ZS_FILE_INVALID); + input_deinit(s, false); + return -1; + } + + size = file_stat.st_size; + s->input.mmaped = true; + + // Try to set the mapped memory advise to sequential. + (void)madvise(start, size, MADV_SEQUENTIAL); + } + + // Set the scanner input limits. + s->input.start = start; + s->input.current = start; + s->input.end = start + size; + + // Get absolute path of the zone file if possible. + char *full_name = realpath(file_name, NULL); + if (full_name != NULL) { + free(s->path); + s->path = strdup(dirname(full_name)); + free(full_name); + if (s->path == NULL) { + ERR(ZS_ENOMEM); + input_deinit(s, false); + return -1; + } + } + + s->file.name = strdup(file_name); + if (s->file.name == NULL) { + ERR(ZS_ENOMEM); + input_deinit(s, false); + return -1; + } + + s->state = ZS_STATE_NONE; + + return 0; +} + +__attribute__((visibility("default"))) +int zs_set_processing( + zs_scanner_t *s, + void (*process_record)(zs_scanner_t *), + void (*process_error)(zs_scanner_t *), + void *data) +{ + if (s == NULL) { + return -1; + } + + s->process.record = process_record; + s->process.error = process_error; + s->process.data = data; + + return 0; +} + +typedef enum { + WRAP_NONE, // Initial state. + WRAP_DETECTED, // Input block end is a first '\' in rdata. + WRAP_PROCESS // Parsing of auxiliary block = "\". +} wrap_t; + +static void parse( + zs_scanner_t *s, + wrap_t *wrap) +{ + // Restore scanner input limits (Ragel internals). + const char *p = s->input.current; + const char *pe = s->input.end; + const char *eof = s->input.eof ? pe : NULL; + + // Restore state variables (Ragel internals). + int cs = s->cs; + int top = s->top; + int stack[ZS_RAGEL_STACK_SIZE]; + memcpy(stack, s->stack, sizeof(stack)); + + // Next 2 variables are for better performance. + // Restoring r_data pointer to next free space. + uint8_t *rdata_tail = s->r_data + s->r_data_tail; + // Initialization of the last r_data byte. + uint8_t *rdata_stop = s->r_data + ZS_MAX_RDATA_LENGTH - 1; + + // Write scanner body (in C). + %% write exec; + + // Check if the scanner state machine is in an uncovered state. + bool extra_error = false; + if (cs == %%{ write error; }%%) { + ERR(ZS_UNCOVERED_STATE); + extra_error = true; + // Check for an unclosed multiline record. + } else if (s->input.eof && s->multiline) { + ERR(ZS_UNCLOSED_MULTILINE); + extra_error = true; + } + + // Treat the extra error. + if (extra_error) { + s->error.counter++; + s->state = ZS_STATE_ERROR; + + // Copy the error context just for the part of the current line. + s->buffer_length = 0; + while (p < pe && *p != '\n' && s->buffer_length < 50) { + s->buffer[s->buffer_length++] = *p++; + } + s->buffer[s->buffer_length++] = 0; + + // Execute the error callback. + if (s->process.automatic && s->process.error != NULL) { + s->process.error(s); + } + + return; + } + + // Storing scanner states. + s->cs = cs; + s->top = top; + memcpy(s->stack, stack, sizeof(stack)); + + // Store the current parser position. + s->input.current = p; + + // Storing r_data pointer. + s->r_data_tail = rdata_tail - s->r_data; + + if (*wrap == WRAP_DETECTED) { + if (set_input_string(s, "\\", 1, true) != 0) { + return; + } + + *wrap = WRAP_PROCESS; + parse(s, wrap); + } else { + *wrap = WRAP_NONE; + } +} + +__attribute__((visibility("default"))) +int zs_parse_record( + zs_scanner_t *s) +{ + if (s == NULL) { + return -1; + } + + // Check if parsing is possible. + switch (s->state) { + case ZS_STATE_NONE: + case ZS_STATE_DATA: + case ZS_STATE_INCLUDE: + break; + case ZS_STATE_ERROR: + if (s->error.fatal) { + return -1; + } + break; + default: + // Return if stop or end of file. + return 0; + } + + // Check for the end of the input. + if (s->input.current != s->input.end) { + // Try to parse another item. + s->state = ZS_STATE_NONE; + wrap_t wrap = WRAP_NONE; + parse(s, &wrap); + + // Finish if nothing was parsed. + if (s->state == ZS_STATE_NONE) { + // Parse the final block. + if (set_input_string(s, "\n", 1, true) != 0) { + return -1; + } + parse(s, &wrap); + if (s->state == ZS_STATE_NONE) { + s->state = ZS_STATE_EOF; + } + } + } else { + s->state = ZS_STATE_EOF; + } + + return 0; +} + +__attribute__((visibility("default"))) +int zs_parse_all( + zs_scanner_t *s) +{ + if (s == NULL) { + return -1; + } + + s->process.automatic = true; + + // Parse input block. + wrap_t wrap = WRAP_NONE; + parse(s, &wrap); + + // Parse trailing newline-char block if it makes sense. + if (s->state != ZS_STATE_STOP && !s->error.fatal) { + if (set_input_string(s, "\n", 1, true) != 0) { + return -1; + } + parse(s, &wrap); + } + + // Check if any errors have occurred. + if (s->error.counter > 0) { + return -1; + } + + return 0; +} |