AU_IO(3)

🎀 AU_IO(3) — the Library Functions Manual, but make it cute 🎀

Okay bestie, gather round: this is the audit-record I/O page. It’s giving “tokens in, tokens out, records handled,” and honestly? Kinda iconic. 💅

💖 NAME 💖

au_fetch_tok, au_print_tok, au_print_flags_tok, au_read_rec — perform I/O involving an audit record. That’s the whole vibe: audit records going in and out. 🦋

📚 LIBRARY 📚

Basic Security Module Library (libbsm, -lbsm) — yes, link that and you’re in. ✨

✨ SYNOPSIS ✨

#include <bsm/libbsm.h>

int
au_fetch_tok(tokenstr_t *tok, u_char *buf, int len);

void
au_print_tok(FILE *outfp, tokenstr_t *tok, char *del, char raw,
    char sfrm);

void
au_print_flags_tok(FILE *outfp, tokenstr_t *tok, char *del, int oflags);

int
au_read_rec(FILE *fp, u_char **buf);

💅 DESCRIPTION 💅

These interfaces support input and output (I/O) involving audit records, internalizing an audit record from a byte stream, converting a token to either a raw or default string, and reading a single record from a file. Like a little audit-record assembly line, but make it fashion. 🎀

The au_fetch_tok() function reads a token from the passed buffer buf of length len bytes, and returns a pointer to the token via tok. Token acquired, bestie. 🫶

The au_print_tok() function prints a string form of the token tok to the file output stream outfp, either in default mode, or raw mode if raw is set non-zero. The delimiter del is used when printing. The au_print_flags_tok() function is a replacement for au_print_tok(). The oflags controls how the output should be formatted and is specified by or’ing the following flags:

• AU_OFLAG_NONE — Use the default form. The classic. 💖
• AU_OFLAG_NORESOLVE — Leave user and group IDs in their numeric form. No name-dropping the IDs. 🔢
• AU_OFLAG_RAW — Use the raw, numeric form. Straight numbers, no filter. 🔥
• AU_OFLAG_SHORT — Use the short form. Keep it cute and concise. 🎀
• AU_OFLAG_XML — Use the XML form. Tags on tags on tags. 🌈

🚨 Bestie warning: the flags options AU_OFLAG_SHORT and AU_OFLAG_RAW are exclusive and should not be used together. Pick one, okay? Don’t make it weird. 💀

The au_read_rec() function reads an audit record from the file stream fp, and returns an allocated memory buffer containing the record via *buf, which must be freed by the caller using free(3). Yes, you gotta free it. The audacity of memory, honestly. 😭

A typical use of these routines might open a file with fopen(3), then read records from the file sequentially by calling au_read_rec(). Each record would be broken down into component tokens through sequential calls to au_fetch_tok() on the buffer, and then invoking au_print_flags_tok() to print each token to an output stream such as stdout. On completion of the processing of each record, a call to free(3) would be used to free the record buffer. Finally, the source stream would be closed by a call to fclose(3). Open, read, tokenize, print, free, close — the whole little routine ate. ✨

🫶 RETURN VALUES 🫶

On success, au_fetch_tok() returns 0 while au_read_rec() returns the number of bytes read. Both functions return -1 on failure with errno set appropriately. Success is 0 or bytes-read; failure is -1, and errno is supposed to spill the tea. 💅

👀 SEE ALSO 👀

• free(3) — release that buffer, bestie. 🧚
• libbsm(3) — the library home base. 🏠

🦋 HISTORY 🦋

The OpenBSM implementation was created by McAfee Research, the security division of McAfee Inc., under contract to Apple Computer, Inc., in 2004. It was subsequently adopted by the TrustedBSD Project as the foundation for the OpenBSM distribution. 2004 called, and it gave us OpenBSM lore. 📜

The au_print_flags_tok() function was added by Stacey Son as a replacement for the au_print_tok() so new output formatting flags can be easily added without changing the API. The au_print_tok() is obsolete but remains in the API to support legacy code. Legacy code said “don’t forget me,” and honestly? Respect. 🫡

👑 AUTHORS 👑

This software was created by Robert Watson, Wayne Salamon, and Suresh Krishnaswamy for McAfee Research, the security research division of McAfee, Inc., under contract to Apple Computer, Inc. Absolute icons of audit-record infrastructure. 🌟

The Basic Security Module (BSM) interface to audit records and audit event stream format were defined by Sun Microsystems. ☀️

🙈 BUGS 🙈

The errno variable may not always be properly set in the event of an error. So yeah, errno is not always giving reliable narrator energy. Keep that in mind. 💀

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Debian build — May 30, 2018 — AU_IO(3) — mwah, kiss kiss 💋💖