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Commit b0dd25a8 authored by Randy Dunlap's avatar Randy Dunlap Committed by Al Viro
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[PATCH] AUDIT: kerneldoc for kernel/audit*.c 

- add kerneldoc for non-static functions;
- don't init static data to 0;
- limit lines to < 80 columns;
- fix long-format style;
- delete whitespace at end of some lines;

(chrisw: resend and update to current audit-2.6 tree)
Signed-off-by: default avatarRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: default avatarChris Wright <chrisw@osdl.org>
Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
parent 7e7f8a03
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Showing with 238 additions and 46 deletions
kernel/audit.c
View file @ b0dd25a8
......@@ -72,7 +72,7 @@ static int audit_failure = AUDIT_FAIL_PRINTK;
* contains the (non-zero) pid. */
int audit_pid;
/* If audit_limit is non-zero, limit the rate of sending audit records
/* If audit_rate_limit is non-zero, limit the rate of sending audit records
* to that number per second. This prevents DoS attacks, but results in
* audit records being dropped. */
static int audit_rate_limit;
......@@ -102,7 +102,7 @@ static struct sock *audit_sock;
* than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
* being placed on the freelist). */
static DEFINE_SPINLOCK(audit_freelist_lock);
static int audit_freelist_count = 0;
static int audit_freelist_count;
static LIST_HEAD(audit_freelist);
static struct sk_buff_head audit_skb_queue;
......@@ -186,8 +186,14 @@ static inline int audit_rate_check(void)
return retval;
}
/* Emit at least 1 message per second, even if audit_rate_check is
* throttling. */
/**
* audit_log_lost - conditionally log lost audit message event
* @message: the message stating reason for lost audit message
*
* Emit at least 1 message per second, even if audit_rate_check is
* throttling.
* Always increment the lost messages counter.
*/
void audit_log_lost(const char *message)
{
static unsigned long last_msg = 0;
......@@ -218,7 +224,6 @@ void audit_log_lost(const char *message)
audit_backlog_limit);
audit_panic(message);
}
}
static int audit_set_rate_limit(int limit, uid_t loginuid)
......@@ -302,6 +307,19 @@ static int kauditd_thread(void *dummy)
}
}
/**
* audit_send_reply - send an audit reply message via netlink
* @pid: process id to send reply to
* @seq: sequence number
* @type: audit message type
* @done: done (last) flag
* @multi: multi-part message flag
* @payload: payload data
* @size: payload size
*
* Allocates an skb, builds the netlink message, and sends it to the pid.
* No failure notifications.
*/
void audit_send_reply(int pid, int seq, int type, int done, int multi,
void *payload, int size)
{
......@@ -376,7 +394,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
if (err)
return err;
/* As soon as there's any sign of userspace auditd, start kauditd to talk to it */
/* As soon as there's any sign of userspace auditd,
* start kauditd to talk to it */
if (!kauditd_task)
kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
if (IS_ERR(kauditd_task)) {
......@@ -469,9 +488,11 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
return err < 0 ? err : 0;
}
/* Get message from skb (based on rtnetlink_rcv_skb). Each message is
/*
* Get message from skb (based on rtnetlink_rcv_skb). Each message is
* processed by audit_receive_msg. Malformed skbs with wrong length are
* discarded silently. */
* discarded silently.
*/
static void audit_receive_skb(struct sk_buff *skb)
{
int err;
......@@ -600,7 +621,10 @@ static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
return NULL;
}
/* Compute a serial number for the audit record. Audit records are
/**
* audit_serial - compute a serial number for the audit record
*
* Compute a serial number for the audit record. Audit records are
* written to user-space as soon as they are generated, so a complete
* audit record may be written in several pieces. The timestamp of the
* record and this serial number are used by the user-space tools to
......@@ -612,8 +636,8 @@ static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
* audit context (for those records that have a context), and emit them
* all at syscall exit. However, this could delay the reporting of
* significant errors until syscall exit (or never, if the system
* halts). */
* halts).
*/
unsigned int audit_serial(void)
{
static spinlock_t serial_lock = SPIN_LOCK_UNLOCKED;
......@@ -649,6 +673,21 @@ static inline void audit_get_stamp(struct audit_context *ctx,
* will be written at syscall exit. If there is no associated task, tsk
* should be NULL. */
/**
* audit_log_start - obtain an audit buffer
* @ctx: audit_context (may be NULL)
* @gfp_mask: type of allocation
* @type: audit message type
*
* Returns audit_buffer pointer on success or NULL on error.
*
* Obtain an audit buffer. This routine does locking to obtain the
* audit buffer, but then no locking is required for calls to
* audit_log_*format. If the task (ctx) is a task that is currently in a
* syscall, then the syscall is marked as auditable and an audit record
* will be written at syscall exit. If there is no associated task, then
* task context (ctx) should be NULL.
*/
struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
int type)
{
......@@ -713,6 +752,7 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
/**
* audit_expand - expand skb in the audit buffer
* @ab: audit_buffer
* @extra: space to add at tail of the skb
*
* Returns 0 (no space) on failed expansion, or available space if
* successful.
......@@ -729,10 +769,12 @@ static inline int audit_expand(struct audit_buffer *ab, int extra)
return skb_tailroom(skb);
}
/* Format an audit message into the audit buffer. If there isn't enough
/*
* Format an audit message into the audit buffer. If there isn't enough
* room in the audit buffer, more room will be allocated and vsnprint
* will be called a second time. Currently, we assume that a printk
* can't format message larger than 1024 bytes, so we don't either. */
* can't format message larger than 1024 bytes, so we don't either.
*/
static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
va_list args)
{
......@@ -757,7 +799,8 @@ static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
/* The printk buffer is 1024 bytes long, so if we get
* here and AUDIT_BUFSIZ is at least 1024, then we can
* log everything that printk could have logged. */
avail = audit_expand(ab, max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
avail = audit_expand(ab,
max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
if (!avail)
goto out;
len = vsnprintf(skb->tail, avail, fmt, args2);
......@@ -768,8 +811,14 @@ static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
return;
}
/* Format a message into the audit buffer. All the work is done in
* audit_log_vformat. */
/**
* audit_log_format - format a message into the audit buffer.
* @ab: audit_buffer
* @fmt: format string
* @...: optional parameters matching @fmt string
*
* All the work is done in audit_log_vformat.
*/
void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
{
va_list args;
......@@ -781,9 +830,18 @@ void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
va_end(args);
}
/* This function will take the passed buf and convert it into a string of
* ascii hex digits. The new string is placed onto the skb. */
void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf,
/**
* audit_log_hex - convert a buffer to hex and append it to the audit skb
* @ab: the audit_buffer
* @buf: buffer to convert to hex
* @len: length of @buf to be converted
*
* No return value; failure to expand is silently ignored.
*
* This function will take the passed buf and convert it into a string of
* ascii hex digits. The new string is placed onto the skb.
*/
void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf,
size_t len)
{
int i, avail, new_len;
......@@ -812,10 +870,16 @@ void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf,
skb_put(skb, len << 1); /* new string is twice the old string */
}
/* This code will escape a string that is passed to it if the string
* contains a control character, unprintable character, double quote mark,
/**
* audit_log_unstrustedstring - log a string that may contain random characters
* @ab: audit_buffer
* @string: string to be logged
*
* This code will escape a string that is passed to it if the string
* contains a control character, unprintable character, double quote mark,
* or a space. Unescaped strings will start and end with a double quote mark.
* Strings that are escaped are printed in hex (2 digits per char). */
* Strings that are escaped are printed in hex (2 digits per char).
*/
void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
{
const unsigned char *p = string;
......@@ -854,10 +918,15 @@ void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
kfree(path);
}
/* The netlink_* functions cannot be called inside an irq context, so
* the audit buffer is places on a queue and a tasklet is scheduled to
/**
* audit_log_end - end one audit record
* @ab: the audit_buffer
*
* The netlink_* functions cannot be called inside an irq context, so
* the audit buffer is placed on a queue and a tasklet is scheduled to
* remove them from the queue outside the irq context. May be called in
* any context. */
* any context.
*/
void audit_log_end(struct audit_buffer *ab)
{
if (!ab)
......@@ -878,9 +947,18 @@ void audit_log_end(struct audit_buffer *ab)
audit_buffer_free(ab);
}
/* Log an audit record. This is a convenience function that calls
* audit_log_start, audit_log_vformat, and audit_log_end. It may be
* called in any context. */
/**
* audit_log - Log an audit record
* @ctx: audit context
* @gfp_mask: type of allocation
* @type: audit message type
* @fmt: format string to use
* @...: variable parameters matching the format string
*
* This is a convenience function that calls audit_log_start,
* audit_log_vformat, and audit_log_end. It may be called
* in any context.
*/
void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
const char *fmt, ...)
{
......
kernel/auditsc.c
View file @ b0dd25a8
......@@ -330,6 +330,15 @@ static int audit_list_rules(void *_dest)
return 0;
}
/**
* audit_receive_filter - apply all rules to the specified message type
* @type: audit message type
* @pid: target pid for netlink audit messages
* @uid: target uid for netlink audit messages
* @seq: netlink audit message sequence (serial) number
* @data: payload data
* @loginuid: loginuid of sender
*/
int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
uid_t loginuid)
{
......@@ -527,7 +536,7 @@ static enum audit_state audit_filter_task(struct task_struct *tsk)
/* At syscall entry and exit time, this filter is called if the
* audit_state is not low enough that auditing cannot take place, but is
* also not high enough that we already know we have to write an audit
* record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
* record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT).
*/
static enum audit_state audit_filter_syscall(struct task_struct *tsk,
struct audit_context *ctx,
......@@ -721,10 +730,15 @@ static inline struct audit_context *audit_alloc_context(enum audit_state state)
return context;
}
/* Filter on the task information and allocate a per-task audit context
/**
* audit_alloc - allocate an audit context block for a task
* @tsk: task
*
* Filter on the task information and allocate a per-task audit context
* if necessary. Doing so turns on system call auditing for the
* specified task. This is called from copy_process, so no lock is
* needed. */
* needed.
*/
int audit_alloc(struct task_struct *tsk)
{
struct audit_context *context;
......@@ -911,8 +925,12 @@ static void audit_log_exit(struct audit_context *context, gfp_t gfp_mask)
}
}
/* Free a per-task audit context. Called from copy_process and
* __put_task_struct. */
/**
* audit_free - free a per-task audit context
* @tsk: task whose audit context block to free
*
* Called from copy_process and __put_task_struct.
*/
void audit_free(struct task_struct *tsk)
{
struct audit_context *context;
......@@ -934,13 +952,24 @@ void audit_free(struct task_struct *tsk)
audit_free_context(context);
}
/* Fill in audit context at syscall entry. This only happens if the
/**
* audit_syscall_entry - fill in an audit record at syscall entry
* @tsk: task being audited
* @arch: architecture type
* @major: major syscall type (function)
* @a1: additional syscall register 1
* @a2: additional syscall register 2
* @a3: additional syscall register 3
* @a4: additional syscall register 4
*
* Fill in audit context at syscall entry. This only happens if the
* audit context was created when the task was created and the state or
* filters demand the audit context be built. If the state from the
* per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT,
* then the record will be written at syscall exit time (otherwise, it
* will only be written if another part of the kernel requests that it
* be written). */
* be written).
*/
void audit_syscall_entry(struct task_struct *tsk, int arch, int major,
unsigned long a1, unsigned long a2,
unsigned long a3, unsigned long a4)
......@@ -950,7 +979,8 @@ void audit_syscall_entry(struct task_struct *tsk, int arch, int major,
BUG_ON(!context);
/* This happens only on certain architectures that make system
/*
* This happens only on certain architectures that make system
* calls in kernel_thread via the entry.S interface, instead of
* with direct calls. (If you are porting to a new
* architecture, hitting this condition can indicate that you
......@@ -1009,11 +1039,18 @@ void audit_syscall_entry(struct task_struct *tsk, int arch, int major,
context->auditable = !!(state == AUDIT_RECORD_CONTEXT);
}
/* Tear down after system call. If the audit context has been marked as
/**
* audit_syscall_exit - deallocate audit context after a system call
* @tsk: task being audited
* @valid: success/failure flag
* @return_code: syscall return value
*
* Tear down after system call. If the audit context has been marked as
* auditable (either because of the AUDIT_RECORD_CONTEXT state from
* filtering, or because some other part of the kernel write an audit
* message), then write out the syscall information. In call cases,
* free the names stored from getname(). */
* free the names stored from getname().
*/
void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code)
{
struct audit_context *context;
......@@ -1048,7 +1085,13 @@ void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code)
put_task_struct(tsk);
}
/* Add a name to the list. Called from fs/namei.c:getname(). */
/**
* audit_getname - add a name to the list
* @name: name to add
*
* Add a name to the list of audit names for this context.
* Called from fs/namei.c:getname().
*/
void audit_getname(const char *name)
{
struct audit_context *context = current->audit_context;
......@@ -1077,10 +1120,13 @@ void audit_getname(const char *name)
}
/* Intercept a putname request. Called from
* include/linux/fs.h:putname(). If we have stored the name from
* getname in the audit context, then we delay the putname until syscall
* exit. */
/* audit_putname - intercept a putname request
* @name: name to intercept and delay for putname
*
* If we have stored the name from getname in the audit context,
* then we delay the putname until syscall exit.
* Called from include/linux/fs.h:putname().
*/
void audit_putname(const char *name)
{
struct audit_context *context = current->audit_context;
......@@ -1117,8 +1163,14 @@ void audit_putname(const char *name)
#endif
}
/* Store the inode and device from a lookup. Called from
* fs/namei.c:path_lookup(). */
/**
* audit_inode - store the inode and device from a lookup
* @name: name being audited
* @inode: inode being audited
* @flags: lookup flags (as used in path_lookup())
*
* Called from fs/namei.c:path_lookup().
*/
void audit_inode(const char *name, const struct inode *inode, unsigned flags)
{
int idx;
......@@ -1154,6 +1206,14 @@ void audit_inode(const char *name, const struct inode *inode, unsigned flags)
context->names[idx].rdev = inode->i_rdev;
}
/**
* auditsc_get_stamp - get local copies of audit_context values
* @ctx: audit_context for the task
* @t: timespec to store time recorded in the audit_context
* @serial: serial value that is recorded in the audit_context
*
* Also sets the context as auditable.
*/
void auditsc_get_stamp(struct audit_context *ctx,
struct timespec *t, unsigned int *serial)
{
......@@ -1165,6 +1225,15 @@ void auditsc_get_stamp(struct audit_context *ctx,
ctx->auditable = 1;
}
/**
* audit_set_loginuid - set a task's audit_context loginuid
* @task: task whose audit context is being modified
* @loginuid: loginuid value
*
* Returns 0.
*
* Called (set) from fs/proc/base.c::proc_loginuid_write().
*/
int audit_set_loginuid(struct task_struct *task, uid_t loginuid)
{
if (task->audit_context) {
......@@ -1183,11 +1252,26 @@ int audit_set_loginuid(struct task_struct *task, uid_t loginuid)
return 0;
}
/**
* audit_get_loginuid - get the loginuid for an audit_context
* @ctx: the audit_context
*
* Returns the context's loginuid or -1 if @ctx is NULL.
*/
uid_t audit_get_loginuid(struct audit_context *ctx)
{
return ctx ? ctx->loginuid : -1;
}
/**
* audit_ipc_perms - record audit data for ipc
* @qbytes: msgq bytes
* @uid: msgq user id
* @gid: msgq group id
* @mode: msgq mode (permissions)
*
* Returns 0 for success or NULL context or < 0 on error.
*/
int audit_ipc_perms(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode)
{
struct audit_aux_data_ipcctl *ax;
......@@ -1211,6 +1295,13 @@ int audit_ipc_perms(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode)
return 0;
}
/**
* audit_socketcall - record audit data for sys_socketcall
* @nargs: number of args
* @args: args array
*
* Returns 0 for success or NULL context or < 0 on error.
*/
int audit_socketcall(int nargs, unsigned long *args)
{
struct audit_aux_data_socketcall *ax;
......@@ -1232,6 +1323,13 @@ int audit_socketcall(int nargs, unsigned long *args)
return 0;
}
/**
* audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto
* @len: data length in user space
* @a: data address in kernel space
*
* Returns 0 for success or NULL context or < 0 on error.
*/
int audit_sockaddr(int len, void *a)
{
struct audit_aux_data_sockaddr *ax;
......@@ -1253,6 +1351,15 @@ int audit_sockaddr(int len, void *a)
return 0;
}
/**
* audit_avc_path - record the granting or denial of permissions
* @dentry: dentry to record
* @mnt: mnt to record
*
* Returns 0 for success or NULL context or < 0 on error.
*
* Called from security/selinux/avc.c::avc_audit()
*/
int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt)
{
struct audit_aux_data_path *ax;
......@@ -1274,6 +1381,14 @@ int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt)
return 0;
}
/**
* audit_signal_info - record signal info for shutting down audit subsystem
* @sig: signal value
* @t: task being signaled
*
* If the audit subsystem is being terminated, record the task (pid)
* and uid that is doing that.
*/
void audit_signal_info(int sig, struct task_struct *t)
{
extern pid_t audit_sig_pid;
......@@ -1290,4 +1405,3 @@ void audit_signal_info(int sig, struct task_struct *t)
}
}
}
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