NetlinkEvent - uevent

原來 NetlinkEvent 是在處理 netlink 的 message。
parsing netlink messaag: bool NetlinkEvent::decode(char *buffer, int size) { char *s = buffer; char *end; int param_idx = 0; int i; int first = 1; end = s + size; while (s < end) { if (first) { char *p; for (p = s; *p != '@'; p++); p++; mPath = strdup(p); first = 0; } else { if (!strncmp(s, "ACTION=", strlen("ACTION="))) { char *a = s + strlen("ACTION="); if (!strcmp(a, "add")) mAction = NlActionAdd; else if (!strcmp(a, "remove")) mAction = NlActionRemove; else if (!strcmp(a, "change")) mAction = NlActionChange; } else if (!strncmp(s, "SEQNUM=", strlen("SEQNUM="))) mSeq = atoi(s + strlen("SEQNUM=")); else if (!strncmp(s, "SUBSYSTEM=", strlen("SUBSYSTEM="))) mSubsystem = strdup(s + strlen("SUBSYSTEM=")); else mParams[param_idx++] = strdup(s); } s+= strlen(s) + 1; } return true; } 可以順便知道kobject, uevent 的 message 內容。
在 Documentation/device-mapper/dm-uevent.txt 有例子：

UEVENT[1192521009.711215] change@/block/dm-3
ACTION=change
DEVPATH=/block/dm-3
SUBSYSTEM=block
DM_TARGET=multipath
DM_ACTION=PATH_FAILED
DM_SEQNUM=1
DM_PATH=8:32
DM_NR_VALID_PATHS=0
DM_NAME=mpath2
DM_UUID=mpath-35333333000002328
MINOR=3
MAJOR=253
SEQNUM=1130