msg: Pretty print generic netlink header in nl_msg_dump()

Signed-off-by: Thomas Graf <tgraf@suug.ch>

diff --git a/lib/msg.c b/lib/msg.c
index b07de630733927c89919fdf9230cdc219e718ccc..dafee6731ddc8c5b0f4158c770d5c5c6134c90e4 100644 (file)
--- a/lib/msg.c
+++ b/lib/msg.c
@@ -767,7 +767,7 @@ static inline void dump_hex(FILE *ofd, char *start, int len, int prefix)
        int i, a, c, limit;
        char ascii[21] = {0};
 
-       limit = 18 - (prefix * 2);
+       limit = 16 - (prefix * 2);
        prefix_line(ofd, prefix);
        fprintf(ofd, "    ");
 
@@ -777,7 +777,7 @@ static inline void dump_hex(FILE *ofd, char *start, int len, int prefix)
                fprintf(ofd, "%02x ", v);
                ascii[a++] = isprint(v) ? v : '.';
 
-               if (c == limit-1) {
+               if (++c >= limit) {
                        fprintf(ofd, "%s\n", ascii);
                        if (i < (len - 1)) {
                                prefix_line(ofd, prefix);
@@ -785,8 +785,7 @@ static inline void dump_hex(FILE *ofd, char *start, int len, int prefix)
                        }
                        a = c = 0;
                        memset(ascii, 0, sizeof(ascii));
-               } else
-                       c++;
+               }
        }
 
        if (c != 0) {
@@ -816,12 +815,60 @@ static void print_hdr(FILE *ofd, struct nl_msg *msg)
        } else
                nl_nlmsgtype2str(nlh->nlmsg_type, buf, sizeof(buf));
 
-       fprintf(ofd, "    .nlmsg_type = %d <%s>\n", nlh->nlmsg_type, buf);
-       fprintf(ofd, "    .nlmsg_flags = %d <%s>\n", nlh->nlmsg_flags,
+       fprintf(ofd, "    .type = %d <%s>\n", nlh->nlmsg_type, buf);
+       fprintf(ofd, "    .flags = %d <%s>\n", nlh->nlmsg_flags,
                nl_nlmsg_flags2str(nlh->nlmsg_flags, buf, sizeof(buf)));
-       fprintf(ofd, "    .nlmsg_seq = %d\n", nlh->nlmsg_seq);
-       fprintf(ofd, "    .nlmsg_pid = %d\n", nlh->nlmsg_pid);
+       fprintf(ofd, "    .seq = %d\n", nlh->nlmsg_seq);
+       fprintf(ofd, "    .port = %d\n", nlh->nlmsg_pid);
+
+}
+
+static void print_genl_hdr(FILE *ofd, void *start)
+{
+       struct genlmsghdr *ghdr = start;
+
+       fprintf(ofd, "  [GENERIC NETLINK HEADER] %zu octets\n", GENL_HDRLEN);
+       fprintf(ofd, "    .cmd = %u\n", ghdr->cmd);
+       fprintf(ofd, "    .version = %u\n", ghdr->version);
+       fprintf(ofd, "    .unused = %#x\n", ghdr->reserved);
+}
+
+static void *print_genl_msg(struct nl_msg *msg, FILE *ofd, struct nlmsghdr *hdr,
+                           struct nl_cache_ops *ops, int *payloadlen)
+{
+       void *data = nlmsg_data(hdr);
+
+       if (*payloadlen < GENL_HDRLEN)
+               return data;
+
+       print_genl_hdr(ofd, data);
+
+       *payloadlen -= GENL_HDRLEN;
+       data += GENL_HDRLEN;
+
+       if (ops) {
+               int hdrsize = ops->co_hdrsize - GENL_HDRLEN;
+
+               if (hdrsize > 0) {
+                       if (*payloadlen < hdrsize)
+                               return data;
+
+                       fprintf(ofd, "  [HEADER] %d octets\n", hdrsize);
+                       dump_hex(ofd, data, hdrsize, 0);
+
+                       *payloadlen -= hdrsize;
+                       data += hdrsize;
+               }
+       }
+
+       return data;
+}
+
+static void dump_attr(FILE *ofd, struct nlattr *attr, int prefix)
+{
+       int len = nla_len(attr);
 
+       dump_hex(ofd, nla_data(attr), len, prefix);
 }
 
 static void dump_attrs(FILE *ofd, struct nlattr *attrs, int attrlen,
@@ -845,7 +892,7 @@ static void dump_attrs(FILE *ofd, struct nlattr *attrs, int attrlen,
                if (nla->nla_type & NLA_F_NESTED)
                        dump_attrs(ofd, nla_data(nla), alen, prefix+1);
                else
-                       dump_hex(ofd, nla_data(nla), alen, prefix);
+                       dump_attr(ofd, nla, prefix);
 
                padlen = nla_padlen(alen);
                if (padlen > 0) {
@@ -884,6 +931,42 @@ static void dump_error_msg(struct nl_msg *msg, FILE *ofd)
        }
 }
 
+static void print_msg(struct nl_msg *msg, FILE *ofd, struct nlmsghdr *hdr)
+{
+       struct nl_cache_ops *ops;
+       int payloadlen = nlmsg_len(hdr);
+       int attrlen = 0;
+       void *data;
+
+       data = nlmsg_data(hdr);
+       ops = nl_cache_ops_associate_safe(nlmsg_get_proto(msg),
+                                         hdr->nlmsg_type);
+       if (ops) {
+               attrlen = nlmsg_attrlen(hdr, ops->co_hdrsize);
+               payloadlen -= attrlen;
+       }
+
+       if (msg->nm_protocol == NETLINK_GENERIC)
+               data = print_genl_msg(msg, ofd, hdr, ops, &payloadlen);
+
+       if (payloadlen) {
+               fprintf(ofd, "  [PAYLOAD] %d octets\n", payloadlen);
+               dump_hex(ofd, data, payloadlen, 0);
+       }
+
+       if (attrlen) {
+               struct nlattr *attrs;
+               int attrlen;
+               
+               attrs = nlmsg_attrdata(hdr, ops->co_hdrsize);
+               attrlen = nlmsg_attrlen(hdr, ops->co_hdrsize);
+               dump_attrs(ofd, attrs, attrlen, 0);
+       }
+
+       if (ops)
+               nl_cache_ops_put(ops);
+}
+
 /**
  * Dump message in human readable format to file descriptor
  * @arg msg            Message to print
@@ -894,45 +977,18 @@ void nl_msg_dump(struct nl_msg *msg, FILE *ofd)
        struct nlmsghdr *hdr = nlmsg_hdr(msg);
        
        fprintf(ofd, 
-       "--------------------------   BEGIN NETLINK MESSAGE "
-       "---------------------------\n");
+       "--------------------------   BEGIN NETLINK MESSAGE ---------------------------\n");
 
-       fprintf(ofd, "  [HEADER] %zu octets\n", sizeof(struct nlmsghdr));
+       fprintf(ofd, "  [NETLINK HEADER] %zu octets\n", sizeof(struct nlmsghdr));
        print_hdr(ofd, msg);
 
        if (hdr->nlmsg_type == NLMSG_ERROR)
                dump_error_msg(msg, ofd);
-       else if (nlmsg_len(hdr) > 0) {
-               struct nl_cache_ops *ops;
-               int payloadlen = nlmsg_len(hdr);
-               int attrlen = 0;
-
-               ops = nl_cache_ops_associate_safe(nlmsg_get_proto(msg),
-                                                 hdr->nlmsg_type);
-               if (ops) {
-                       attrlen = nlmsg_attrlen(hdr, ops->co_hdrsize);
-                       payloadlen -= attrlen;
-               }
-
-               fprintf(ofd, "  [PAYLOAD] %d octets\n", payloadlen);
-               dump_hex(ofd, nlmsg_data(hdr), payloadlen, 0);
-
-               if (attrlen) {
-                       struct nlattr *attrs;
-                       int attrlen;
-                       
-                       attrs = nlmsg_attrdata(hdr, ops->co_hdrsize);
-                       attrlen = nlmsg_attrlen(hdr, ops->co_hdrsize);
-                       dump_attrs(ofd, attrs, attrlen, 0);
-               }
-
-               if (ops)
-                       nl_cache_ops_put(ops);
-       }
+       else if (nlmsg_len(hdr) > 0)
+               print_msg(msg, ofd, hdr);
 
        fprintf(ofd, 
-       "---------------------------  END NETLINK MESSAGE   "
-       "---------------------------\n");
+       "---------------------------  END NETLINK MESSAGE   ---------------------------\n");
 }
 
 /** @} */