GETAUDIT(2)

💖 GETAUDIT(2) — System Calls Manual 💖

okay bestie, come sit with me because we're about to get so cozy with the audit subsystem. this is getaudit and getaudit_addr, two lil system calls from the System Calls Manual section 2, and they're literally just here to hand you the current audit session state. that's it. that's the whole job. and they ate. 🎀

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✨ NAME ✨

getaudit, getaudit_addr — retrieve audit session state

like, the vibes of "who am I in the audit world right now." 🦋

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✨ SYNOPSIS ✨

#include <bsm/audit.h>

int
getaudit(auditinfo_t *auditinfo);

int
getaudit_addr(auditinfo_addr_t *auditinfo_addr, u_int length);

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✨ DESCRIPTION ✨

so the way this works: the getaudit() system call retrieves the active audit session state for the current process, and it does that through the auditinfo_t that auditinfo points at. meanwhile getaudit_addr() retrieves the extended state, and it does that via auditinfo_addr and length. two sisters, slightly different jobs. 💅

the auditinfo_t data structure is defined like this:

struct auditinfo {
        au_id_t        ai_auid;         /* Audit user ID */
        au_mask_t      ai_mask;         /* Audit masks */
        au_tid_t       ai_termid;       /* Terminal ID */
        au_asid_t      ai_asid;         /* Audit session ID */
};
typedef struct auditinfo        auditinfo_t;

the ai_auid variable holds the audit identifier which is recorded in the audit log for each event the process caused. so every time your process does a thing, this is the ID that gets written down. main character energy fr fr 👑

the au_mask_t data structure defines the bit mask for auditing successful and failed events out of the predefined list of event classes. it's defined as follows:

struct au_mask {
        unsigned int    am_success;     /* success bits */
        unsigned int    am_failure;     /* failure bits */
};
typedef struct au_mask  au_mask_t;

the au_termid_t data structure defines the Terminal ID recorded with every event caused by the process. it's defined as follows:

struct au_tid {
        dev_t           port;
        u_int32_t       machine;
};
typedef struct au_tid   au_tid_t;

the ai_asid variable contains the audit session ID which is recorded with every event caused by the process. 🍓

now — and this is the glow-up — the getaudit_addr() system call uses the expanded auditinfo_addr_t data structure and supports Terminal IDs with larger addresses, such as those used in IP version 6. yes bestie, IPv6. she's evolved. 🌈 it's defined as follows:

struct auditinfo_addr {
        au_id_t         ai_auid;        /* Audit user ID. */
        au_mask_t       ai_mask;        /* Audit masks. */
        au_tid_addr_t   ai_termid;      /* Terminal ID. */
        au_asid_t       ai_asid;        /* Audit session ID. */
};
typedef struct auditinfo_addr   auditinfo_addr_t;

and the au_tid_addr_t data structure, which includes a larger address storage field and an additional field with the type of address stored:

struct au_tid_addr {
        dev_t           at_port;
        u_int32_t       at_type;
        u_int32_t       at_addr[4];
};
typedef struct au_tid_addr      au_tid_addr_t;

⚠️ important bestie: these system calls require an appropriate privilege to complete. like, you can't just waltz in here unprivileged. it's giving velvet rope. 🚫

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✨ RETURN VALUES ✨

the getaudit() and getaudit_addr() functions return the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error. classic. zero means slay, minus-one means check errno and cry a little. 😭

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✨ ERRORS ✨

the getaudit() function will fail if:

• [EFAULT] — A failure occurred while data transferred to or from the kernel failed.
• [EINVAL] — Illegal argument was passed by a system call.
• [EPERM] — The process does not have sufficient permission to complete the operation.
• [EOVERFLOW] — The length argument indicates an overflow condition will occur.
• [E2BIG] — The address is too big and, therefore, getaudit_addr() should be used instead. (she's telling you to upgrade, respectfully 💅)

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✨ SEE ALSO ✨

audit(2), auditon(2), getauid(2), setaudit(2), setauid(2), libbsm(3)

go read those too, bestie. iykyk. 📚

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✨ 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. a whole origin story. ✨

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✨ AUTHORS ✨

this software was created by McAfee Research, the security research division of McAfee, Inc., under contract to Apple Computer Inc. additional authors include Wayne Salamon, Robert Watson, and SPARTA Inc. 🫶

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

this manual page was written by Robert Watson <rwatson@FreeBSD.org>. give him his flowers. 💐

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and that's the whole page, babe! this little legend came to you from Debian, dated October 19, 2008 — yes she's a 2008 baby and she's still iconic. 💖 no cap. 🎀✨