Fix: out of bound strcpy

[lttng-tools.git] / src / common / utils.c

diff --git a/src/common/utils.c b/src/common/utils.c
index 1c2b95d3e7d5d3e427bc4c20f59ba4483062dea9..38f78a7e8e7d40cd6fcebefd297e5bb240c52aaf 100644 (file)
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -26,6 +26,7 @@
 #include <sys/stat.h>
 #include <unistd.h>
 #include <inttypes.h>
+#include <regex.h>
 
 #include <common/common.h>
 #include <common/runas.h>
@@ -394,3 +395,192 @@ int utils_rotate_stream_file(char *path_name, char *file_name, uint64_t size,
 error:
        return ret;
 }
+
+/**
+ * Prints the error message corresponding to a regex error code.
+ *
+ * @param errcode      The error code.
+ * @param regex                The regex object that produced the error code.
+ */
+static void regex_print_error(int errcode, regex_t *regex)
+{
+       /* Get length of error message and allocate accordingly */
+       size_t length;
+       char *buffer;
+
+       assert(regex != NULL);
+
+       length = regerror(errcode, regex, NULL, 0);
+       if (length == 0) {
+               ERR("regerror returned a length of 0");
+               return;
+       }
+
+       buffer = zmalloc(length);
+       if (!buffer) {
+               ERR("regex_print_error: zmalloc failed");
+               return;
+       }
+
+       /* Get and print error message */
+       regerror(errcode, regex, buffer, length);
+       ERR("regex error: %s\n", buffer);
+       free(buffer);
+
+}
+
+/**
+ * Parse a string that represents a size in human readable format. It
+ * supports decimal integers suffixed by 'k', 'M' or 'G'.
+ *
+ * The suffix multiply the integer by:
+ * 'k': 1024
+ * 'M': 1024^2
+ * 'G': 1024^3
+ *
+ * @param str  The string to parse.
+ * @param size Pointer to a size_t that will be filled with the
+ *             resulting size.
+ *
+ * @return 0 on success, -1 on failure.
+ */
+int utils_parse_size_suffix(char *str, uint64_t *size)
+{
+       regex_t regex;
+       int ret;
+       const int nmatch = 3;
+       regmatch_t suffix_match, matches[nmatch];
+       unsigned long long base_size;
+       long shift = 0;
+
+       if (!str) {
+               return 0;
+       }
+
+       /* Compile regex */
+       ret = regcomp(&regex, "^\\(0x\\)\\{0,1\\}[0-9][0-9]*\\([kKMG]\\{0,1\\}\\)$", 0);
+       if (ret != 0) {
+               regex_print_error(ret, &regex);
+               ret = -1;
+               goto end;
+       }
+
+       /* Match regex */
+       ret = regexec(&regex, str, nmatch, matches, 0);
+       if (ret != 0) {
+               ret = -1;
+               goto free;
+       }
+
+       /* There is a match ! */
+       errno = 0;
+       base_size = strtoull(str, NULL, 0);
+       if (errno != 0) {
+               PERROR("strtoull");
+               ret = -1;
+               goto free;
+       }
+
+       /* Check if there is a suffix */
+       suffix_match = matches[2];
+       if (suffix_match.rm_eo - suffix_match.rm_so == 1) {
+               switch (*(str + suffix_match.rm_so)) {
+               case 'K':
+               case 'k':
+                       shift = KIBI_LOG2;
+                       break;
+               case 'M':
+                       shift = MEBI_LOG2;
+                       break;
+               case 'G':
+                       shift = GIBI_LOG2;
+                       break;
+               default:
+                       ERR("parse_human_size: invalid suffix");
+                       ret = -1;
+                       goto free;
+               }
+       }
+
+       *size = base_size << shift;
+
+       /* Check for overflow */
+       if ((*size >> shift) != base_size) {
+               ERR("parse_size_suffix: oops, overflow detected.");
+               ret = -1;
+               goto free;
+       }
+
+       ret = 0;
+
+free:
+       regfree(&regex);
+end:
+       return ret;
+}
+
+/*
+ * fls: returns the position of the most significant bit.
+ * Returns 0 if no bit is set, else returns the position of the most
+ * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit).
+ */
+#if defined(__i386) || defined(__x86_64)
+static inline unsigned int fls_u32(uint32_t x)
+{
+       int r;
+
+       asm("bsrl %1,%0\n\t"
+               "jnz 1f\n\t"
+               "movl $-1,%0\n\t"
+               "1:\n\t"
+               : "=r" (r) : "rm" (x));
+       return r + 1;
+}
+#define HAS_FLS_U32
+#endif
+
+#ifndef HAS_FLS_U32
+static __attribute__((unused)) unsigned int fls_u32(uint32_t x)
+{
+       unsigned int r = 32;
+
+       if (!x) {
+               return 0;
+       }
+       if (!(x & 0xFFFF0000U)) {
+               x <<= 16;
+               r -= 16;
+       }
+       if (!(x & 0xFF000000U)) {
+               x <<= 8;
+               r -= 8;
+       }
+       if (!(x & 0xF0000000U)) {
+               x <<= 4;
+               r -= 4;
+       }
+       if (!(x & 0xC0000000U)) {
+               x <<= 2;
+               r -= 2;
+       }
+       if (!(x & 0x80000000U)) {
+               x <<= 1;
+               r -= 1;
+       }
+       return r;
+}
+#endif
+
+/*
+ * Return the minimum order for which x <= (1UL << order).
+ * Return -1 if x is 0.
+ */
+LTTNG_HIDDEN
+int utils_get_count_order_u32(uint32_t x)
+{
+       if (!x) {
+               return -1;
+       }
+
+       return fls_u32(x - 1);
+}