* **-E2BIG** if the *buf_len* is too big.
*
* **-EINVAL** if sysctl is being read.
+ *
+ * int bpf_strtol(const char *buf, size_t buf_len, u64 flags, long *res)
+ * Description
+ * Convert the initial part of the string from buffer *buf* of
+ * size *buf_len* to a long integer according to the given base
+ * and save the result in *res*.
+ *
+ * The string may begin with an arbitrary amount of white space
+ * (as determined by isspace(3)) followed by a single optional '-'
+ * sign.
+ *
+ * Five least significant bits of *flags* encode base, other bits
+ * are currently unused.
+ *
+ * Base must be either 8, 10, 16 or 0 to detect it automatically
+ * similar to user space strtol(3).
+ * Return
+ * Number of characters consumed on success. Must be positive but
+ * no more than buf_len.
+ *
+ * **-EINVAL** if no valid digits were found or unsupported base
+ * was provided.
+ *
+ * **-ERANGE** if resulting value was out of range.
+ *
+ * int bpf_strtoul(const char *buf, size_t buf_len, u64 flags, unsigned long *res)
+ * Description
+ * Convert the initial part of the string from buffer *buf* of
+ * size *buf_len* to an unsigned long integer according to the
+ * given base and save the result in *res*.
+ *
+ * The string may begin with an arbitrary amount of white space
+ * (as determined by isspace(3)).
+ *
+ * Five least significant bits of *flags* encode base, other bits
+ * are currently unused.
+ *
+ * Base must be either 8, 10, 16 or 0 to detect it automatically
+ * similar to user space strtoul(3).
+ * Return
+ * Number of characters consumed on success. Must be positive but
+ * no more than buf_len.
+ *
+ * **-EINVAL** if no valid digits were found or unsupported base
+ * was provided.
+ *
+ * **-ERANGE** if resulting value was out of range.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
FN(sysctl_get_name), \
FN(sysctl_get_current_value), \
FN(sysctl_get_new_value), \
- FN(sysctl_set_new_value),
+ FN(sysctl_set_new_value), \
+ FN(strtol), \
+ FN(strtoul),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
#include <linux/sched.h>
#include <linux/uidgid.h>
#include <linux/filter.h>
+#include <linux/ctype.h>
+
+#include "../../lib/kstrtox.h"
/* If kernel subsystem is allowing eBPF programs to call this function,
* inside its own verifier_ops->get_func_proto() callback it should return
.arg2_type = ARG_ANYTHING,
};
#endif
+
+#define BPF_STRTOX_BASE_MASK 0x1F
+
+static int __bpf_strtoull(const char *buf, size_t buf_len, u64 flags,
+ unsigned long long *res, bool *is_negative)
+{
+ unsigned int base = flags & BPF_STRTOX_BASE_MASK;
+ const char *cur_buf = buf;
+ size_t cur_len = buf_len;
+ unsigned int consumed;
+ size_t val_len;
+ char str[64];
+
+ if (!buf || !buf_len || !res || !is_negative)
+ return -EINVAL;
+
+ if (base != 0 && base != 8 && base != 10 && base != 16)
+ return -EINVAL;
+
+ if (flags & ~BPF_STRTOX_BASE_MASK)
+ return -EINVAL;
+
+ while (cur_buf < buf + buf_len && isspace(*cur_buf))
+ ++cur_buf;
+
+ *is_negative = (cur_buf < buf + buf_len && *cur_buf == '-');
+ if (*is_negative)
+ ++cur_buf;
+
+ consumed = cur_buf - buf;
+ cur_len -= consumed;
+ if (!cur_len)
+ return -EINVAL;
+
+ cur_len = min(cur_len, sizeof(str) - 1);
+ memcpy(str, cur_buf, cur_len);
+ str[cur_len] = '\0';
+ cur_buf = str;
+
+ cur_buf = _parse_integer_fixup_radix(cur_buf, &base);
+ val_len = _parse_integer(cur_buf, base, res);
+
+ if (val_len & KSTRTOX_OVERFLOW)
+ return -ERANGE;
+
+ if (val_len == 0)
+ return -EINVAL;
+
+ cur_buf += val_len;
+ consumed += cur_buf - str;
+
+ return consumed;
+}
+
+static int __bpf_strtoll(const char *buf, size_t buf_len, u64 flags,
+ long long *res)
+{
+ unsigned long long _res;
+ bool is_negative;
+ int err;
+
+ err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
+ if (err < 0)
+ return err;
+ if (is_negative) {
+ if ((long long)-_res > 0)
+ return -ERANGE;
+ *res = -_res;
+ } else {
+ if ((long long)_res < 0)
+ return -ERANGE;
+ *res = _res;
+ }
+ return err;
+}
+
+BPF_CALL_4(bpf_strtol, const char *, buf, size_t, buf_len, u64, flags,
+ long *, res)
+{
+ long long _res;
+ int err;
+
+ err = __bpf_strtoll(buf, buf_len, flags, &_res);
+ if (err < 0)
+ return err;
+ if (_res != (long)_res)
+ return -ERANGE;
+ *res = _res;
+ return err;
+}
+
+const struct bpf_func_proto bpf_strtol_proto = {
+ .func = bpf_strtol,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_CONST_SIZE,
+ .arg3_type = ARG_ANYTHING,
+ .arg4_type = ARG_PTR_TO_LONG,
+};
+
+BPF_CALL_4(bpf_strtoul, const char *, buf, size_t, buf_len, u64, flags,
+ unsigned long *, res)
+{
+ unsigned long long _res;
+ bool is_negative;
+ int err;
+
+ err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
+ if (err < 0)
+ return err;
+ if (is_negative)
+ return -EINVAL;
+ if (_res != (unsigned long)_res)
+ return -ERANGE;
+ *res = _res;
+ return err;
+}
+
+const struct bpf_func_proto bpf_strtoul_proto = {
+ .func = bpf_strtoul,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_MEM,
+ .arg2_type = ARG_CONST_SIZE,
+ .arg3_type = ARG_ANYTHING,
+ .arg4_type = ARG_PTR_TO_LONG,
+};
#endif