Add some comments and clean up the code a bit - smdev - suckless mdev
(HTM) git clone git://git.suckless.org/smdev
(DIR) Log
(DIR) Files
(DIR) Refs
(DIR) README
(DIR) LICENSE
---
(DIR) commit 5f48a52f383ac2a646b4608195372a314a91e7e5
(DIR) parent dd397daae5b0314ad124195a67d02f0bf5cad009
(HTM) Author: sin <sin@2f30.org>
Date: Fri, 23 Aug 2013 12:24:22 +0100
Add some comments and clean up the code a bit
Diffstat:
M config.h | 4 ++--
M smdev.c | 130 +++++++++++++++++--------------
2 files changed, 74 insertions(+), 60 deletions(-)
---
(DIR) diff --git a/config.h b/config.h
@@ -1,12 +1,12 @@
/* See LICENSE file for copyright and license details. */
-struct Rule {
+struct rule {
char *devregex;
char *user;
char *group;
int mode;
char *path;
char *cmd;
-} Rules[] = {
+} rules[] = {
{ "null", "root", "root", 0666, NULL, "@chmod 666 $SMDEV" },
{ "zero", "root", "root", 0666, NULL, NULL },
{ "full", "root", "root", 0666, NULL, NULL },
(DIR) diff --git a/smdev.c b/smdev.c
@@ -24,28 +24,29 @@ enum action {
UNKNOWN_ACTION
};
-struct Event {
+struct event {
int min;
int maj;
enum action action;
char *devpath;
char *devname;
- struct Rule *Rule;
+ struct rule *rule;
};
+/* Simple cache for regcomp() */
static struct pregentry {
regex_t preg;
int cached;
-} pregcache[LEN(Rules)];
+} pregcache[LEN(rules)];
static int dohotplug(void);
static int matchrule(int ruleidx, char *devname);
-static void runrule(struct Rule *Rule);
-static void parsepath(struct Rule *Rule, char *devpath, size_t sz,
- char *devname);
-static int createdev(struct Event *ev);
-static int doevent(struct Event *ev);
-static int craftev(struct Event *ev, enum action action,
+static void runrule(struct rule *rule);
+static void parsepath(struct rule *rule, char *devpath,
+ size_t devpathsz, char *devname);
+static int createdev(struct event *ev);
+static int doevent(struct event *ev);
+static int craftev(struct event *ev, enum action action,
char *sysfspath);
static void populatedev(const char *path);
@@ -93,12 +94,13 @@ mapaction(const char *action)
return UNKNOWN_ACTION;
}
+/* Handle hotplugging events */
static int
dohotplug(void)
{
char *min, *maj;
char *action;
- struct Event ev;
+ struct event ev;
min = getenv("MINOR");
maj = getenv("MAJOR");
@@ -116,17 +118,21 @@ dohotplug(void)
return doevent(&ev);
}
+/*
+ * `ruleidx' indexes into the rules[] table. We assume
+ * pregcache[] is mapped 1-1 with the rules[] table.
+ */
static int
matchrule(int ruleidx, char *devname)
{
- struct Rule *Rule = &Rules[ruleidx];
+ struct rule *rule = &rules[ruleidx];
regex_t *match;
regmatch_t off;
int ret;
if (!pregcache[ruleidx].cached) {
ret = regcomp(&pregcache[ruleidx].preg,
- Rule->devregex, REG_EXTENDED);
+ rule->devregex, REG_EXTENDED);
if (ret < 0)
eprintf("regcomp:");
pregcache[ruleidx].cached = 1;
@@ -140,53 +146,58 @@ matchrule(int ruleidx, char *devname)
}
static void
-runrule(struct Rule *Rule)
+runrule(struct rule *rule)
{
- if (!Rule->cmd)
+ if (!rule->cmd)
return;
- system(&Rule->cmd[1]);
+ system(&rule->cmd[1]);
}
+/*
+ * Parse rule->path[] and set `devpath' to the absolute
+ * path of the device node. If we have to rename the
+ * device node then set `devname' to the new device name.
+ */
static void
-parsepath(struct Rule *Rule, char *devpath, size_t sz,
+parsepath(struct rule *rule, char *devpath, size_t devpathsz,
char *devname)
{
char buf[BUFSIZ], *p;
char *dirc, *basec;
- if (Rule->path[0] != '=' && Rule->path[0] != '>')
- eprintf("Invalid path '%s'\n", Rule->path);
+ if (rule->path[0] != '=' && rule->path[0] != '>')
+ eprintf("Invalid path '%s'\n", rule->path);
- p = strchr(&Rule->path[1], '/');
+ p = strchr(&rule->path[1], '/');
if (p) {
- if (Rule->path[strlen(Rule->path) - 1] == '/') {
- snprintf(devpath, sz, "/dev/%s%s",
- &Rule->path[1], devname);
- } else {
- dirc = strdup(&Rule->path[1]);
- if (!dirc)
- eprintf("strdup:");
- snprintf(buf, sizeof(buf), "/dev/%s", dirname(dirc));
- free(dirc);
- basec = strdup(&Rule->path[1]);
- if (!basec)
- eprintf("strdup:");
- strlcpy(devname, basename(basec), sizeof(devname));
- free(basec);
- snprintf(devpath, sz, "%s/%s",
- buf, devname);
+ if (rule->path[strlen(rule->path) - 1] == '/') {
+ snprintf(devpath, devpathsz, "/dev/%s%s",
+ &rule->path[1], devname);
+ return;
}
+ dirc = strdup(&rule->path[1]);
+ if (!dirc)
+ eprintf("strdup:");
+ snprintf(buf, sizeof(buf), "/dev/%s", dirname(dirc));
+ free(dirc);
+ basec = strdup(&rule->path[1]);
+ if (!basec)
+ eprintf("strdup:");
+ strlcpy(devname, basename(basec), sizeof(devname));
+ free(basec);
+ snprintf(devpath, devpathsz, "%s/%s",
+ buf, devname);
} else {
- strlcpy(devname, &Rule->path[1], sizeof(devname));
- snprintf(devpath, sz, "/dev/%s", devname);
+ strlcpy(devname, &rule->path[1], sizeof(devname));
+ snprintf(devpath, devpathsz, "/dev/%s", devname);
}
}
static int
-createdev(struct Event *ev)
+createdev(struct event *ev)
{
- struct Rule *Rule;
+ struct rule *rule;
struct passwd *pw;
struct group *gr;
char *dirc;
@@ -195,7 +206,7 @@ createdev(struct Event *ev)
char buf[BUFSIZ];
int type;
- Rule = ev->Rule;
+ rule = ev->rule;
snprintf(buf, sizeof(buf), "%d:%d", ev->maj, ev->min);
type = devtype(buf);
@@ -205,8 +216,9 @@ createdev(struct Event *ev)
strlcpy(devname, ev->devname, sizeof(devname));
snprintf(devpath, sizeof(devpath), "/dev/%s", devname);
- if (Rule->path) {
- parsepath(Rule, devpath, sizeof(devpath),
+ /* Parse path and create the directory tree */
+ if (rule->path) {
+ parsepath(rule, devpath, sizeof(devpath),
devname);
dirc = strdup(devpath);
if (!dirc)
@@ -219,33 +231,33 @@ createdev(struct Event *ev)
umask(0);
}
- /* Create the actual dev nodes */
- if (mknod(devpath, Rule->mode | type,
+ /* Create the actual dev node */
+ if (mknod(devpath, rule->mode | type,
makedev(ev->maj, ev->min)) < 0 &&
errno != EEXIST)
eprintf("mknod %s:", devpath);
errno = 0;
- pw = getpwnam(Rule->user);
+ pw = getpwnam(rule->user);
if (errno)
- eprintf("getpwnam %s:", Rule->user);
+ eprintf("getpwnam %s:", rule->user);
else if (!pw)
enprintf(1, "getpwnam %s: no such user\n",
- Rule->user);
+ rule->user);
errno = 0;
- gr = getgrnam(Rule->group);
+ gr = getgrnam(rule->group);
if (errno)
- eprintf("getgrnam %s:", Rule->group);
+ eprintf("getgrnam %s:", rule->group);
else if (!gr)
enprintf(1, "getgrnam %s: no such group\n",
- Rule->group);
+ rule->group);
if (chown(devpath, pw->pw_uid, gr->gr_gid) < 0)
eprintf("chown %s:", devpath);
- /* Create symlinks */
- if (Rule->path && Rule->path[0] == '>') {
+ /* Create symlink */
+ if (rule->path && rule->path[0] == '>') {
snprintf(buf, sizeof(buf), "/dev/%s", ev->devname);
if (symlink(devpath, buf))
eprintf("symlink %s -> %s:",
@@ -256,20 +268,21 @@ createdev(struct Event *ev)
if (putenv(buf) < 0)
eprintf("putenv:");
- runrule(Rule);
+ runrule(rule);
return 0;
}
+/* Event dispatcher */
static int
-doevent(struct Event *ev)
+doevent(struct event *ev)
{
int i;
- for (i = 0; i < LEN(Rules); i++) {
+ for (i = 0; i < LEN(rules); i++) {
if (matchrule(i, ev->devname) < 0)
continue;
- ev->Rule = &Rules[i];
+ ev->rule = &rules[i];
switch (ev->action) {
case ADD_ACTION:
return createdev(ev);
@@ -281,8 +294,9 @@ doevent(struct Event *ev)
return 0;
}
+/* Craft a fake event so the rest of the code can cope */
static int
-craftev(struct Event *ev, enum action action, char *sysfspath)
+craftev(struct event *ev, enum action action, char *sysfspath)
{
char path[PATH_MAX];
@@ -300,7 +314,7 @@ static void
populatedev(const char *path)
{
char *cwd;
- struct Event ev;
+ struct event ev;
recurse(path, populatedev);
if (!strcmp(path, "dev")) {