Updated: April 19, 2023 |
Construct an Internet domain name query
#include <sys/types.h> #include <netinet/in.h> #include <arpa/nameser.h> #include <resolv.h> int res_mkquery( int op, const char * dname, int class, int type, const u_char * data, int datalen, const u_char * newrr, u_char * buf, int buflen );
You typically use C_IN.
The res_mkquery() function is a low-level routine that's used by res_query() to construct an Internet domain name query. This routine constructs a standard query message and places it in buf. It returns the size of the query, or -1 if the query is larger than buflen.
The resolver routines are used for making, sending, and interpreting query and reply messages with Internet domain name servers. Global configuration and state information used by the resolver routines is kept in the structure _res. For more information on the options, see res_init().
Based on:
RFC 974, RFC 1032, RFC 1033, RFC 1034, RFC 1035
The size of the prepared query, in bytes, or -1 if an error occurs.
Safety: | |
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Cancellation point | Yes |
Interrupt handler | No |
Signal handler | No |
Thread | No |