3 files changed, 42 insertions, 0 deletions

diff --git a/libbb/create_icmp_socket.c b/libbb/create_icmp_socket.c
new file mode 100644
index 000000000..d804b3987
--- /dev/null
+++ b/libbb/create_icmp_socket.c
@@ -0,0 +1,37 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * create raw socket for icmp protocol test permision
+ * and drop root privilegies if running setuid
+ *
+ */
+
+#include <sys/types.h>
+#include <netdb.h>
+#include <sys/socket.h>
+#include <errno.h>
+#include <unistd.h>
+#include "libbb.h"
+
+int create_icmp_socket(void)
+{
+        struct protoent *proto;
+        int sock;
+
+        proto = getprotobyname("icmp");
+        /* if getprotobyname failed, just silently force
+         * proto->p_proto to have the correct value for "icmp" */
+        if ((sock = socket(AF_INET, SOCK_RAW,
+                        (proto ? proto->p_proto : 1))) < 0) {        /* 1 == ICMP */
+                if (errno == EPERM)
+                        error_msg_and_die("permission denied. (are you root?)");
+                else
+                        perror_msg_and_die(can_not_create_raw_socket);
+        }
+
+        /* drop root privs if running setuid */
+        setuid(getuid());
+
+        return sock;
+}
diff --git a/libbb/libbb.h b/libbb/libbb.h
index 224c561d5..e3d713321 100644
--- a/libbb/libbb.h
+++ b/libbb/libbb.h
@@ -252,6 +252,7 @@ extern void gz_close(int gunzip_pid);
 extern FILE *gz_open(FILE *compressed_file, int *pid);
 
 extern struct hostent *xgethostbyname(const char *name);
+extern int create_icmp_socket(void);
 
 char *dirname (const char *path);
 
@@ -284,5 +285,6 @@ extern const char * const write_error;
 extern const char * const too_few_args;
 extern const char * const name_longer_than_foo;
 extern const char * const unknown;
+extern const char * const can_not_create_raw_socket;
 
 #endif /* __LIBBB_H__ */
diff --git a/libbb/messages.c b/libbb/messages.c
index 910cb8fa2..552c3ab5b 100644
--- a/libbb/messages.c
+++ b/libbb/messages.c
@@ -62,3 +62,6 @@
         const char * const unknown = "(unknown)";
 #endif
 
+#ifdef L_can_not_create_raw_socket
+        const char * const can_not_create_raw_socket = "can`t create raw socket";
+#endif