mongoose/src/util.c

#include "util.h"

#if MG_ARCH == MG_ARCH_UNIX && defined(__APPLE__)
#include <mach/mach_time.h>
#endif

#if MG_ENABLE_FILE
char *mg_file_read(const char *path, size_t *sizep) {
  FILE *fp;
  char *data = NULL;
  size_t size = 0;
  if ((fp = fopen(path, "rb")) != NULL) {
    fseek(fp, 0, SEEK_END);
    size = (size_t) ftell(fp);
    rewind(fp);
    data = (char *) calloc(1, size + 1);
    if (data != NULL) {
      if (fread(data, 1, size, fp) != size) {
        free(data);
        data = NULL;
      } else {
        data[size] = '\0';
        if (sizep != NULL) *sizep = size;
      }
    }
    fclose(fp);
  }
  return data;
}

bool mg_file_write(const char *path, const void *buf, size_t len) {
  bool result = false;
  FILE *fp;
  char tmp[MG_PATH_MAX];
  snprintf(tmp, sizeof(tmp), "%s.%d", path, rand());
  fp = fopen(tmp, "wb");
  if (fp != NULL) {
    result = fwrite(buf, 1, len, fp) == len;
    fclose(fp);
    if (result) {
      remove(path);
      rename(tmp, path);
    } else {
      remove(tmp);
    }
  }
  return result;
}
#endif

bool mg_file_printf(const char *path, const char *fmt, ...) {
  char tmp[256], *buf = tmp;
  bool result;
  int len;
  va_list ap;
  va_start(ap, fmt);
  len = mg_vasprintf(&buf, sizeof(tmp), fmt, ap);
  va_end(ap);
  result = mg_file_write(path, buf, len > 0 ? (size_t) len : 0);
  if (buf != tmp) free(buf);
  return result;
}

#if MG_ENABLE_CUSTOM_RANDOM
#else
void mg_random(void *buf, size_t len) {
  bool done = false;
  unsigned char *p = (unsigned char *) buf;
#if MG_ARCH == MG_ARCH_ESP32
  while (len--) *p++ = (unsigned char) (esp_random() & 255);
  done = true;
#elif MG_ARCH == MG_ARCH_WIN32
#elif MG_ARCH_UNIX
  FILE *fp = fopen("/dev/urandom", "rb");
  if (fp != NULL) {
    if (fread(buf, 1, len, fp) == len) done = true;
    fclose(fp);
  }
#endif
  // If everything above did not work, fallback to a pseudo random generator
  while (!done && len--) *p++ = (unsigned char) (rand() & 255);
}
#endif

bool mg_globmatch(const char *s1, size_t n1, const char *s2, size_t n2) {
  size_t i = 0, j = 0, ni = 0, nj = 0;
  while (i < n1 || j < n2) {
    if (i < n1 && j < n2 && (s1[i] == '?' || s2[j] == s1[i])) {
      i++, j++;
    } else if (i < n1 && (s1[i] == '*' || s1[i] == '#')) {
      ni = i, nj = j + 1, i++;
    } else if (nj > 0 && nj <= n2 && (s1[ni] == '#' || s2[j] != '/')) {
      i = ni, j = nj;
    } else {
      // printf(">>: [%s] [%s] %d %d %d %d\n", s1, s2, i, j, ni, nj);
      return false;
    }
  }
  return true;
}

static size_t mg_nce(const char *s, size_t n, size_t ofs, size_t *koff,
                     size_t *klen, size_t *voff, size_t *vlen) {
  size_t kvlen, kl;
  for (kvlen = 0; ofs + kvlen < n && s[ofs + kvlen] != ',';) kvlen++;
  for (kl = 0; kl < kvlen && s[ofs + kl] != '=';) kl++;
  if (koff != NULL) *koff = ofs;
  if (klen != NULL) *klen = kl;
  if (voff != NULL) *voff = kl < kvlen ? ofs + kl + 1 : 0;
  if (vlen != NULL) *vlen = kl < kvlen ? kvlen - kl - 1 : 0;
  ofs += kvlen + 1;
  return ofs > n ? n : ofs;
}

bool mg_commalist(struct mg_str *s, struct mg_str *k, struct mg_str *v) {
  size_t koff = 0, klen = 0, voff = 0, vlen = 0;
  size_t off = mg_nce(s->ptr, s->len, 0, &koff, &klen, &voff, &vlen);
  if (k != NULL) *k = mg_str_n(s->ptr + koff, klen);
  if (v != NULL) *v = mg_str_n(s->ptr + voff, vlen);
  *s = mg_str_n(s->ptr + off, s->len - off);
  return off > 0;
}

uint32_t mg_ntohl(uint32_t net) {
  uint8_t data[4] = {0, 0, 0, 0};
  memcpy(&data, &net, sizeof(data));
  return (((uint32_t) data[3]) << 0) | (((uint32_t) data[2]) << 8) |
         (((uint32_t) data[1]) << 16) | (((uint32_t) data[0]) << 24);
}

uint16_t mg_ntohs(uint16_t net) {
  uint8_t data[2] = {0, 0};
  memcpy(&data, &net, sizeof(data));
  return (uint16_t) ((uint16_t) data[1] | (((uint16_t) data[0]) << 8));
}

char *mg_hexdump(const void *buf, size_t len) {
  const unsigned char *p = (const unsigned char *) buf;
  size_t i, idx, n = 0, ofs = 0, dlen = len * 5 + 100;
  char ascii[17] = "", *dst = (char *) calloc(1, dlen);
  if (dst == NULL) return dst;
  for (i = 0; i < len; i++) {
    idx = i % 16;
    if (idx == 0) {
      if (i > 0 && dlen > n)
        n += (size_t) snprintf(dst + n, dlen - n, "  %s\n", ascii);
      if (dlen > n)
        n += (size_t) snprintf(dst + n, dlen - n, "%04x ", (int) (i + ofs));
    }
    if (dlen < n) break;
    n += (size_t) snprintf(dst + n, dlen - n, " %02x", p[i]);
    ascii[idx] = (char) (p[i] < 0x20 || p[i] > 0x7e ? '.' : p[i]);
    ascii[idx + 1] = '\0';
  }
  while (i++ % 16) {
    if (n < dlen) n += (size_t) snprintf(dst + n, dlen - n, "%s", "   ");
  }
  if (n < dlen) n += (size_t) snprintf(dst + n, dlen - n, "  %s\n", ascii);
  if (n > dlen - 1) n = dlen - 1;
  dst[n] = '\0';
  return dst;
}

char *mg_hex(const void *buf, size_t len, char *to) {
  const unsigned char *p = (const unsigned char *) buf;
  static const char *hex = "0123456789abcdef";
  size_t i = 0;
  for (; len--; p++) {
    to[i++] = hex[p[0] >> 4];
    to[i++] = hex[p[0] & 0x0f];
  }
  to[i] = '\0';
  return to;
}

static unsigned char mg_unhex_nimble(unsigned char c) {
  return (c >= '0' && c <= '9')   ? (unsigned char) (c - '0')
         : (c >= 'A' && c <= 'F') ? (unsigned char) (c - '7')
                                  : (unsigned char) (c - 'W');
}

unsigned long mg_unhexn(const char *s, size_t len) {
  unsigned long i = 0, v = 0;
  for (i = 0; i < len; i++) v <<= 4, v |= mg_unhex_nimble(((uint8_t *) s)[i]);
  return v;
}

void mg_unhex(const char *buf, size_t len, unsigned char *to) {
  size_t i;
  for (i = 0; i < len; i += 2) {
    to[i >> 1] = (unsigned char) mg_unhexn(&buf[i], 2);
  }
}

int mg_vasprintf(char **buf, size_t size, const char *fmt, va_list ap) {
  va_list ap_copy;
  int len;

  va_copy(ap_copy, ap);
  len = vsnprintf(*buf, size, fmt, ap_copy);
  va_end(ap_copy);

  if (len < 0) {
    // eCos and Windows are not standard-compliant and return -1 when
    // the buffer is too small. Keep allocating larger buffers until we
    // succeed or out of memory.
    // LCOV_EXCL_START
    *buf = NULL;
    while (len < 0) {
      free(*buf);
      if (size == 0) size = 5;
      size *= 2;
      if ((*buf = (char *) calloc(1, size)) == NULL) {
        len = -1;
        break;
      }
      va_copy(ap_copy, ap);
      len = vsnprintf(*buf, size - 1, fmt, ap_copy);
      va_end(ap_copy);
    }
    // Microsoft version of vsnprintf() is not always null-terminated, so put
    // the terminator manually
    if (*buf != NULL) (*buf)[len] = 0;
    // LCOV_EXCL_STOP
  } else if (len >= (int) size) {
    /// Standard-compliant code path. Allocate a buffer that is large enough
    if ((*buf = (char *) calloc(1, (size_t) len + 1)) == NULL) {
      len = -1;  // LCOV_EXCL_LINE
    } else {     // LCOV_EXCL_LINE
      va_copy(ap_copy, ap);
      len = vsnprintf(*buf, (size_t) len + 1, fmt, ap_copy);
      va_end(ap_copy);
    }
  }

  return len;
}

int mg_asprintf(char **buf, size_t size, const char *fmt, ...) {
  int ret;
  va_list ap;
  va_start(ap, fmt);
  ret = mg_vasprintf(buf, size, fmt, ap);
  va_end(ap);
  return ret;
}

int64_t mg_to64(struct mg_str str) {
  int64_t result = 0, neg = 1, max = 922337203685477570 /* INT64_MAX/10-10 */;
  size_t i = 0;
  while (i < str.len && (str.ptr[i] == ' ' || str.ptr[i] == '\t')) i++;
  if (i < str.len && str.ptr[i] == '-') neg = -1, i++;
  while (i < str.len && str.ptr[i] >= '0' && str.ptr[i] <= '9') {
    if (result > max) return 0;
    result *= 10;
    result += (str.ptr[i] - '0');
    i++;
  }
  return result * neg;
}

uint32_t mg_crc32(uint32_t crc, const char *buf, size_t len) {
  int i;
  crc = ~crc;
  while (len--) {
    crc ^= *(unsigned char *) buf++;
    for (i = 0; i < 8; i++) crc = crc & 1 ? (crc >> 1) ^ 0xedb88320 : crc >> 1;
  }
  return ~crc;
}

static int isbyte(int n) {
  return n >= 0 && n <= 255;
}

static int parse_net(const char *spec, uint32_t *net, uint32_t *mask) {
  int n, a, b, c, d, slash = 32, len = 0;
  if ((sscanf(spec, "%d.%d.%d.%d/%d%n", &a, &b, &c, &d, &slash, &n) == 5 ||
       sscanf(spec, "%d.%d.%d.%d%n", &a, &b, &c, &d, &n) == 4) &&
      isbyte(a) && isbyte(b) && isbyte(c) && isbyte(d) && slash >= 0 &&
      slash < 33) {
    len = n;
    *net = ((uint32_t) a << 24) | ((uint32_t) b << 16) | ((uint32_t) c << 8) |
           (uint32_t) d;
    *mask = slash ? (uint32_t) (0xffffffffU << (32 - slash)) : (uint32_t) 0;
  }
  return len;
}

int mg_check_ip_acl(struct mg_str acl, uint32_t remote_ip) {
  struct mg_str k, v;
  int allowed = acl.len == 0 ? '+' : '-';  // If any ACL is set, deny by default
  while (mg_commalist(&acl, &k, &v)) {
    uint32_t net, mask;
    if (k.ptr[0] != '+' && k.ptr[0] != '-') return -1;
    if (parse_net(&k.ptr[1], &net, &mask) == 0) return -2;
    if ((remote_ip & mask) == net) allowed = k.ptr[0];
  }
  return allowed == '+';
}

int64_t mg_millis(void) {
#if MG_ARCH == MG_ARCH_WIN32
  return GetTickCount();
#elif MG_ARCH == MG_ARCH_ESP32
  return esp_timer_get_time() / 1000;
#elif MG_ARCH == MG_ARCH_ESP8266
  return xTaskGetTickCount() * portTICK_PERIOD_MS;
#elif MG_ARCH == MG_ARCH_FREERTOS_TCP || MG_ARCH == MG_ARCH_FREERTOS_LWIP
  return xTaskGetTickCount() * portTICK_PERIOD_MS;
#elif MG_ARCH == MG_ARCH_AZURERTOS
  return tx_time_get() * (1000 /* MS per SEC */ / TX_TIMER_TICKS_PER_SECOND);
#elif MG_ARCH == MG_ARCH_UNIX && defined(__APPLE__)
  uint64_t ticks = mach_absolute_time();
  static mach_timebase_info_data_t timebase;
  mach_timebase_info(&timebase);
  double ticks_to_nanos = (double) timebase.numer / timebase.denom;
  uint64_t uptime_nanos = (uint64_t) (ticks_to_nanos * ticks);
  return (int64_t) (uptime_nanos / 1000000);
#else
  struct timespec ts;
#ifdef _POSIX_MONOTONIC_CLOCK
#ifdef CLOCK_MONOTONIC_RAW
  clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
#else
  clock_gettime(CLOCK_MONOTONIC, &ts);
#endif
#else
  clock_gettime(CLOCK_REALTIME, &ts);
#endif
  return ((int64_t) ts.tv_sec * 1000 + (int64_t) ts.tv_nsec / 1000000);
#endif
}