diff --git a/src/common/linux/linux_libc_support.cc b/src/common/linux/linux_libc_support.cc
--- a/src/common/linux/linux_libc_support.cc
+++ b/src/common/linux/linux_libc_support.cc
@@ -133,16 +133,27 @@ const char* my_strrchr(const char* hayst
   while (*haystack) {
     if (*haystack == needle)
       ret = haystack;
     haystack++;
   }
   return ret;
 }
 
+const char* my_strstr(const char* haystack, const char* needle) {
+  while (*haystack != 0) {
+    if((*haystack == *needle) &&
+       (my_strncmp(haystack, needle, my_strlen(needle)) == 0)) {
+      return haystack;
+    }
+    haystack++;
+  }
+  return nullptr;
+}
+
 void* my_memchr(const void* src, int needle, size_t src_len) {
   const unsigned char* p = (const unsigned char*)src;
   const unsigned char* p_end = p + src_len;
   for (; p < p_end; ++p) {
     if (*p == needle)
       return (void*)p;
   }
   return NULL;
diff --git a/src/common/linux/linux_libc_support.h b/src/common/linux/linux_libc_support.h
--- a/src/common/linux/linux_libc_support.h
+++ b/src/common/linux/linux_libc_support.h
@@ -62,16 +62,18 @@ extern unsigned my_uint_len(uintmax_t i)
 //   i: the unsigned integer to serialise.
 //   i_len: the length of the integer in base 10 (see |my_uint_len|).
 extern void my_uitos(char* output, uintmax_t i, unsigned i_len);
 
 extern const char* my_strchr(const char* haystack, char needle);
 
 extern const char* my_strrchr(const char* haystack, char needle);
 
+extern const char *my_strstr(const char *haystack, const char *needle);
+
 // Read a hex value
 //   result: (output) the resulting value
 //   s: a string
 // Returns a pointer to the first invalid charactor.
 extern const char* my_read_hex_ptr(uintptr_t* result, const char* s);
 
 extern const char* my_read_decimal_ptr(uintptr_t* result, const char* s);