Introduce struct Event and add primitive hotplugging support - smdev - suckless mdev
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---
(DIR) commit cf0ac2f526b5e82d94a1cd02428ebd8bfb5cb00b
(DIR) parent 18552e102e3d739d8c03379716b8acbc9ddbc8f7
(HTM) Author: sin <sin@2f30.org>
Date: Thu, 22 Aug 2013 10:45:24 +0100
Introduce struct Event and add primitive hotplugging support
This unifies the way we handle hotplug events versus static
population of the /dev directory. We also remove the assumption
for createdev() to only work correctly if the current directory
is set to the corresponding sysfs entry.
Diffstat:
M config.h | 10 +++++-----
M smdev.c | 144 ++++++++++++++++++++-----------
2 files changed, 97 insertions(+), 57 deletions(-)
---
(DIR) diff --git a/config.h b/config.h
@@ -1,11 +1,11 @@
/* See LICENSE file for copyright and license details. */
struct Rule {
- const char *devregex;
- const char *user;
- const char *group;
+ char *devregex;
+ char *user;
+ char *group;
int mode;
- const char *path;
- const char *cmd;
+ char *path;
+ char *cmd;
} Rules[] = {
{ "null", "root", "root", 0666, NULL, "@chmod 666 $SMDEV" },
{ "zero", "root", "root", 0666, NULL, NULL },
(DIR) diff --git a/smdev.c b/smdev.c
@@ -15,9 +15,18 @@
#include "mkpath.h"
#include "util.h"
-static int matchrule(const struct Rule *Rule, const char *devname);
-static int create_dev(const char *path);
-static void sysrecurse(const char *path);
+struct Event {
+ int min;
+ int maj;
+ char *action;
+ char *devpath;
+ char *devname;
+};
+
+static int dohotplug(void);
+static int matchrule(struct Rule *Rule, char *devname);
+static int createdev(struct Event *ev);
+static void populatedev(const char *path);
static void
usage(void)
@@ -38,17 +47,43 @@ main(int argc, char *argv[])
usage();
} ARGEND;
- if (!sflag)
- usage();
-
umask(0);
- recurse("/sys/devices", sysrecurse);
+ if (sflag)
+ recurse("/sys/devices", populatedev);
+ else
+ if (dohotplug() < 0)
+ return 1;
+ return 0;
+}
+
+static int
+dohotplug(void)
+{
+ char *min, *maj;
+ struct Event ev;
+
+ min = getenv("MINOR");
+ maj = getenv("MAJOR");
+ ev.action = getenv("ACTION");
+ ev.devpath = getenv("DEVPATH");
+ ev.devname = getenv("DEVNAME");
+ if (!min || !maj || !ev.action || !ev.devpath ||
+ !ev.devname)
+ return -1;
+
+ ev.min = estrtol(min, 10);
+ ev.maj = estrtol(maj, 10);
+
+ if (!strcmp(ev.action, "add"))
+ return createdev(&ev);
+ else
+ eprintf("Unsupported action '%s'\n", ev.action);
return 0;
}
static int
-matchrule(const struct Rule *Rule, const char *devname)
+matchrule(struct Rule *Rule, char *devname)
{
regex_t match;
regmatch_t off;
@@ -67,37 +102,23 @@ matchrule(const struct Rule *Rule, const char *devname)
}
static int
-create_dev(const char *path)
+createdev(struct Event *ev)
{
struct Rule *Rule;
struct passwd *pw;
struct group *gr;
- char buf[BUFSIZ], *p;
- const char *devname;
- char origdevname[PATH_MAX];
- int maj, min, type;
- int i, ret;
-
- p = strrchr(path, '/');
- if (!p)
- return -1;
- p++;
- devname = p;
- snprintf(origdevname, sizeof(origdevname), "/dev/%s", devname);
+ char devpath[PATH_MAX], *devname;
+ char buf[BUFSIZ];
+ int type;
+ int i;
- snprintf(buf, sizeof(buf), "%s/dev", path);
- ret = devtomajmin(buf, &maj, &min);
- if (ret < 0)
- return -1;
-
- snprintf(buf, sizeof(buf), "%d:%d", maj, min);
+ snprintf(buf, sizeof(buf), "%d:%d", ev->maj, ev->min);
type = devtype(buf);
if (type < 0)
return -1;
- if (chdir("/dev") < 0)
- eprintf("chdir /dev:");
-
+ devname = ev->devname;
+ snprintf(devpath, sizeof(devpath), "/dev/%s", devname);
for (i = 0; i < LEN(Rules); i++) {
Rule = &Rules[i];
@@ -108,40 +129,53 @@ create_dev(const char *path)
if (Rule->path[0] != '=' && Rule->path[0] != '>')
eprintf("Invalid path '%s'\n", Rule->path);
if (Rule->path[strlen(Rule->path) - 1] == '/') {
+ snprintf(buf, sizeof(buf), "/dev/%s", &Rule->path[1]);
umask(022);
- if (mkpath(&Rule->path[1], 0755) < 0)
- eprintf("mkdir %s:", &Rule->path[1]);
+ if (mkpath(buf, 0755) < 0)
+ eprintf("mkdir %s:", buf);
umask(0);
- if (chdir(&Rule->path[1]) < 0)
- eprintf("chdir %s:", &Rule->path[1]);
+ snprintf(devpath, sizeof(devpath), "/dev/%s%s",
+ &Rule->path[1], devname);
} else {
devname = &Rule->path[1];
+ snprintf(devpath, sizeof(devpath), "/dev/%s", devname);
}
}
/* Create the actual dev nodes */
- ret = mknod(devname, Rules[i].mode | type, makedev(maj, min));
- if (ret < 0 && errno != EEXIST)
- eprintf("mknod %s:", devname);
+ if (mknod(devpath, Rules[i].mode | type,
+ makedev(ev->maj, ev->min)) < 0 &&
+ errno != EEXIST)
+ eprintf("mknod %s:", devpath);
+
+ errno = 0;
pw = getpwnam(Rules[i].user);
- if (!pw)
+ if (errno)
eprintf("getpwnam %s:", Rules[i].user);
+ else if (!pw)
+ enprintf(1, "getpwnam %s: no such user\n",
+ Rules[i].user);
+
+ errno = 0;
gr = getgrnam(Rules[i].group);
- if (!gr)
+ if (errno)
eprintf("getgrnam %s:", Rules[i].group);
- ret = chown(devname, pw->pw_uid, gr->gr_gid);
- if (ret < 0)
- eprintf("chown %s:", devname);
+ else if (!gr)
+ enprintf(1, "getgrnam %s: no such group\n",
+ Rules[i].group);
+
+ if (chown(devpath, pw->pw_uid, gr->gr_gid) < 0)
+ eprintf("chown %s:", devpath);
/* Create symlinks */
if (Rule->path && Rule->path[0] == '>') {
- snprintf(buf, sizeof(buf), "%s%s", &Rule->path[1], devname);
- if (symlink(buf, origdevname))
+ snprintf(buf, sizeof(buf), "/dev/%s", ev->devname);
+ if (symlink(devpath, buf))
eprintf("symlink %s -> %s:",
- origdevname, buf);
+ ev->devname, devpath);
}
- snprintf(buf, sizeof(buf), "SMDEV=%s", devname);
+ snprintf(buf, sizeof(buf), "SMDEV=%s", devpath);
if (putenv(buf) < 0)
eprintf("putenv:");
@@ -162,21 +196,27 @@ create_dev(const char *path)
break;
}
- if (chdir(path) < 0)
- eprintf("chdir %s:", path);
-
return 0;
}
static void
-sysrecurse(const char *path)
+populatedev(const char *path)
{
+ char tmppath[PATH_MAX];
char *cwd;
+ struct Event ev;
- recurse(path, sysrecurse);
+ recurse(path, populatedev);
if (!strcmp(path, "dev")) {
cwd = agetcwd();
- create_dev(cwd);
+ ev.action = "add";
+ ev.devpath = cwd + strlen("/sys");
+ ev.devname = basename(cwd);
+ snprintf(tmppath, sizeof(tmppath), "/sys%s/dev",
+ ev.devpath);
+ if (devtomajmin(tmppath, &ev.maj, &ev.min) < 0)
+ return;
+ createdev(&ev);
free(cwd);
}
}