Kernel Functions for Drivers rmvb(9F)
NAME
rmvb - remove a message block from a message
SYNOPSIS
#include
mblk_t *rmvb(mblk_t *mp, mblk_t *bp);
INTERFACE LEVEL
Architecture independent level 1 (DDI/DKI).
PARAMETERS
mp Message from which a block is to be removed. mblk_t is
an instance of the msgb(9S) structure. bp Message block to be removed.DESCRIPTION
The rmvb() function removes a message block (bp) from a mes-
sage (mp), and returns a pointer to the altered message. The message block is not freed, merely removed from the message.It is the module or driver's responsibility to free the mes-
sage block.RETURN VALUES
If successful, a pointer to the message (minus the removed block) is returned. The pointer is NULL if bp was the onlyblock of the message before rmvb() was called. If the
designated message block (bp) does not exist, -1 is
returned.CONTEXT
The rmvb() function can be called from user, interrupt, or
kernel context.EXAMPLES
This routine removes all zero-length M_DATA message blocks
from the given message. For each message block in the mes-
sage, save the next message block (line 10). If the currentmessage block is of type M_DATA and has no data in its
buffer (line 11), then remove it from the message (line 12) and free it (line 13). In either case, continue with the next message block in the message (line 16). 1 void 2 xxclean(mp)3 mblk_t *mp;
SunOS 5.11 Last change: 16 Jan 2006 1
Kernel Functions for Drivers rmvb(9F)
4 {5 mblk_t *tmp;
6 mblk_t *nmp;
7 8 tmp = mp; 9 while (tmp) {10 nmp = tmp->b_cont;
11 if ((tmp->b_datap->db_type == M_DATA) &&
(tmp->b_rptr == tmp->b_wptr)) {
12 (void) rmvb(mp, tmp);
13 freeb(tmp); 14 } 15 tmp = nmp; 16 } 17 }SEE ALSO
freeb(9F), msgb(9S) Writing Device Drivers STREAMS Programming GuideSunOS 5.11 Last change: 16 Jan 2006 2