io: change size types from unsigned long to kernel_ureg_t

[strace] / netlink.c

diff --git a/netlink.c b/netlink.c
index c43f6e74ac6b55f9b462377ebd76df259dd67de2..13ff1c55343161799cbb5924abb9feb7973aa705 100644 (file)
--- a/netlink.c
+++ b/netlink.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2016 Fabien Siron <fabien.siron@epita.fr>
+ * Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,34 +32,102 @@
 #include "xlat/netlink_flags.h"
 #include "xlat/netlink_types.h"
 
-void
-decode_netlink(struct tcb *tcp, unsigned long addr, unsigned long size)
+/*
+ * Fetch a struct nlmsghdr from the given address.
+ */
+static bool
+fetch_nlmsghdr(struct tcb *const tcp, struct nlmsghdr *const nlmsghdr,
+              const kernel_ureg_t addr, const unsigned long len)
 {
-       struct nlmsghdr nlmsghdr;
-
-       if (size < sizeof(struct nlmsghdr)) {
-               printstr(tcp, addr, size);
-               return;
+       if (len < sizeof(struct nlmsghdr)) {
+               printstrn(tcp, addr, len);
+               return false;
        }
-       if (umove_or_printaddr(tcp, addr, &nlmsghdr))
-               return;
 
-       tprintf("{{len=%u, type=", nlmsghdr.nlmsg_len);
+       if (umove_or_printaddr(tcp, addr, nlmsghdr))
+               return false;
+
+       return true;
+}
+
+static void
+print_nlmsghdr(struct tcb *tcp, const struct nlmsghdr *const nlmsghdr)
+{
+       /* print the whole structure regardless of its nlmsg_len */
+
+       tprintf("{len=%u, type=", nlmsghdr->nlmsg_len);
 
-       printxval(netlink_types, nlmsghdr.nlmsg_type, "NLMSG_???");
+       printxval(netlink_types, nlmsghdr->nlmsg_type, "NLMSG_???");
 
        tprints(", flags=");
-       printflags(netlink_flags, nlmsghdr.nlmsg_flags, "NLM_F_???");
-       /* manage get/new requests */
+       printflags(netlink_flags, nlmsghdr->nlmsg_flags, "NLM_F_???");
+
+       tprintf(", seq=%u, pid=%u}", nlmsghdr->nlmsg_seq,
+               nlmsghdr->nlmsg_pid);
+}
 
-       tprintf(", seq=%u, pid=%u}", nlmsghdr.nlmsg_seq,
-               nlmsghdr.nlmsg_pid);
+static void
+decode_nlmsghdr_with_payload(struct tcb *const tcp,
+                            const struct nlmsghdr *const nlmsghdr,
+                            const kernel_ureg_t addr,
+                            const unsigned long len)
+{
+       tprints("{");
+
+       print_nlmsghdr(tcp, nlmsghdr);
 
-       if (size - sizeof(struct nlmsghdr) > 0) {
+       unsigned long nlmsg_len =
+               nlmsghdr->nlmsg_len > len ? len : nlmsghdr->nlmsg_len;
+       if (nlmsg_len > sizeof(struct nlmsghdr)) {
                tprints(", ");
-               printstr(tcp, addr + sizeof(struct nlmsghdr),
-                        size - sizeof(struct nlmsghdr));
+
+               printstrn(tcp, addr + sizeof(struct nlmsghdr),
+                        nlmsg_len - sizeof(struct nlmsghdr));
        }
 
        tprints("}");
 }
+
+void
+decode_netlink(struct tcb *const tcp, kernel_ureg_t addr, unsigned long len)
+{
+       struct nlmsghdr nlmsghdr;
+       bool print_array = false;
+       unsigned int elt;
+
+       for (elt = 0; fetch_nlmsghdr(tcp, &nlmsghdr, addr, len); elt++) {
+               if (abbrev(tcp) && elt == max_strlen) {
+                       tprints("...");
+                       break;
+               }
+
+               unsigned long nlmsg_len = NLMSG_ALIGN(nlmsghdr.nlmsg_len);
+               kernel_ureg_t next_addr = 0;
+               unsigned long next_len = 0;
+
+               if (nlmsghdr.nlmsg_len >= sizeof(struct nlmsghdr)) {
+                       next_len = (len >= nlmsg_len) ? len - nlmsg_len : 0;
+
+                       if (next_len && addr + nlmsg_len > addr)
+                               next_addr = addr + nlmsg_len;
+               }
+
+               if (!print_array && next_addr) {
+                       tprints("[");
+                       print_array = true;
+               }
+
+               decode_nlmsghdr_with_payload(tcp, &nlmsghdr, addr, len);
+
+               if (!next_addr)
+                       break;
+
+               tprints(", ");
+               addr = next_addr;
+               len = next_len;
+       }
+
+       if (print_array) {
+               tprints("]");
+       }
+}