Hi Rob, In the entry data structure, there is a field called 'attr'. This contains various attributes, including the AS PATH: see bgpdump_attr.h: struct attr { <snip> struct aspath *aspath; } struct aspath { u_int8_t asn_len; int length; int count; caddr_t data; char *str; }; The 'data' is the raw attribute, but libbgpdump also helpfully fills in 'str' as a decoded string representation of the AS Path (using function process_attr_aspath_string). So to access it, quoting from what bgpdump.c and example.c does: if (entry->attr && entry->attr->len) { if( (entry->attr->flag & ATTR_FLAG_BIT(BGP_ATTR_AS_PATH) ) !=0) { printf("ASPATH: %s\n",entry->attr->aspath->str); } } Hope this helps, if you need some more help with it, just let me know. Colin (bgpdump maintainer) On 06-11-2023 19:59, Rob Ballantyne wrote:
Hello All,
I’ve just started looking at libbgpdump for a project where I will be parsing MRT/BGP data.
I’ve managed, following the example/advice I’ve seen, to get a basic loop running through an update file from the repository working.
However, I don’t seem to be able to find the ASPATH component in the parsed data structure.
I can see the type/subtype of the data block is BGPDUMP_TYPE_ZEBRA_BGP/BGPDUMP_SUBTYPE_ZEBRA_BGP_MESSAGE.I can also see that the BGPDUMP_BODY is a discriminated union based on these values. I can see that BGPDUMP_ENTRY.attr should probably contain an ASPATH but it doesn’t seem to be set ever.
Should I be expecting the ASPATH to be set in this case? Should I be doing something different (calling some init function after discovering the BGPDUMP_BODY is of the right type?).
Thanks!
Rob