[git commit] networking/interface.c: get rid of global data
Denys Vlasenko
vda.linux at googlemail.com
Mon Mar 5 17:30:33 UTC 2018
commit: https://git.busybox.net/busybox/commit/?id=d51ba0b5ab13aa09ab0482bd2dc63f39e8b40fad
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master
These were data/bss:
static.proc_read 1 - -1
int_list 4 - -4
int_last 4 - -4
We never call display_interfaces() twice, thus code to not scan /proc twice
never triggers.
function old new delta
do_if_print - 1998 +1998
display_interfaces 145 249 +104
static.proc_read 1 - -1
add_interface 104 103 -1
int_list 4 - -4
int_last 4 - -4
if_readlist_proc 560 542 -18
if_readconf 141 - -141
do_if_fetch 643 - -643
ife_print 1296 - -1296
------------------------------------------------------------------------------
(add/remove: 1/6 grow/shrink: 1/2 up/down: 2102/-2108) Total: -6 bytes
text data bss dec hex filename
933084 473 6844 940401 e5971 busybox_old
933087 473 6836 940396 e596c busybox_unstripped
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
networking/interface.c | 121 +++++++++++++++----------------------------------
1 file changed, 36 insertions(+), 85 deletions(-)
diff --git a/networking/interface.c b/networking/interface.c
index ff99c2981..e5e55d8d4 100644
--- a/networking/interface.c
+++ b/networking/interface.c
@@ -341,8 +341,9 @@ struct interface {
#endif
};
-
-static struct interface *int_list, *int_last;
+struct iface_list {
+ struct interface *int_list, *int_last;
+};
#if 0
@@ -373,11 +374,11 @@ static int nstrcmp(const char *a, const char *b)
}
#endif
-static struct interface *add_interface(char *name)
+static struct interface *add_interface(struct iface_list *ilist, char *name)
{
struct interface *ife, **nextp, *new;
- for (ife = int_last; ife; ife = ife->prev) {
+ for (ife = ilist->int_last; ife; ife = ife->prev) {
int n = /*n*/strcmp(ife->name, name);
if (n == 0)
@@ -388,13 +389,14 @@ static struct interface *add_interface(char *name)
new = xzalloc(sizeof(*new));
strncpy_IFNAMSIZ(new->name, name);
- nextp = ife ? &ife->next : &int_list;
+
+ nextp = ife ? &ife->next : &ilist->int_list;
new->prev = ife;
new->next = *nextp;
if (new->next)
new->next->prev = new;
else
- int_last = new;
+ ilist->int_last = new;
*nextp = new;
return new;
}
@@ -500,12 +502,12 @@ static int procnetdev_version(char *buf)
return 0;
}
-static int if_readconf(void)
+static void if_readconf(struct iface_list *ilist)
{
int numreqs = 30;
struct ifconf ifc;
struct ifreq *ifr;
- int n, err;
+ int n;
int skfd;
ifc.ifc_buf = NULL;
@@ -518,10 +520,7 @@ static int if_readconf(void)
ifc.ifc_len = sizeof(struct ifreq) * numreqs;
ifc.ifc_buf = xrealloc(ifc.ifc_buf, ifc.ifc_len);
- err = ioctl_or_warn(skfd, SIOCGIFCONF, &ifc);
- if (err < 0) {
- goto out;
- }
+ xioctl(skfd, SIOCGIFCONF, &ifc);
if (ifc.ifc_len == (int)(sizeof(struct ifreq) * numreqs)) {
/* assume it overflowed and try again */
numreqs += 10;
@@ -532,71 +531,54 @@ static int if_readconf(void)
ifr = ifc.ifc_req;
for (n = 0; n < ifc.ifc_len; n += sizeof(struct ifreq)) {
- add_interface(ifr->ifr_name);
+ add_interface(ilist, ifr->ifr_name);
ifr++;
}
- err = 0;
- out:
close(skfd);
free(ifc.ifc_buf);
- return err;
}
-static int if_readlist_proc(char *target)
+static int if_readlist_proc(struct iface_list *ilist, char *ifname)
{
- static smallint proc_read;
-
FILE *fh;
char buf[512];
struct interface *ife;
- int err, procnetdev_vsn;
-
- if (proc_read)
- return 0;
- if (!target)
- proc_read = 1;
+ int procnetdev_vsn;
+ int ret;
fh = fopen_or_warn(_PATH_PROCNET_DEV, "r");
if (!fh) {
- return if_readconf();
+ return 0; /* "not found" */
}
fgets(buf, sizeof buf, fh); /* eat line */
fgets(buf, sizeof buf, fh);
procnetdev_vsn = procnetdev_version(buf);
- err = 0;
+ ret = 0;
while (fgets(buf, sizeof buf, fh)) {
char *s, name[IFNAMSIZ];
s = get_name(name, buf);
- ife = add_interface(name);
+ ife = add_interface(ilist, name);
get_dev_fields(s, ife, procnetdev_vsn);
ife->statistics_valid = 1;
- if (target && strcmp(target, name) == 0)
+ if (ifname && strcmp(ifname, name) == 0) {
+ ret = 1; /* found */
break;
+ }
}
-
-#if 0 /* we trust kernel to not be buggy, /proc/net/dev reads never fail */
- if (ferror(fh)) {
- bb_perror_msg(_PATH_PROCNET_DEV);
- err = -1;
- proc_read = 0;
- }
-#endif
-
fclose(fh);
- return err;
+ return ret;
}
-static int if_readlist(void)
+static void if_readlist(struct iface_list *ilist, char *ifname)
{
- int err = if_readlist_proc(NULL);
+ int found = if_readlist_proc(ilist, ifname);
/* Needed in order to get ethN:M aliases */
- if (!err)
- err = if_readconf();
- return err;
+ if (!found)
+ if_readconf(ilist);
}
/* Fetch the interface configuration from the kernel. */
@@ -1096,50 +1078,21 @@ static int do_if_print(struct interface *ife, int show_downed_too)
return res;
}
-static struct interface *lookup_interface(char *name)
-{
- struct interface *ife = NULL;
-
- if (if_readlist_proc(name) < 0)
- return NULL;
- ife = add_interface(name);
- return ife;
-}
-
-#ifdef UNUSED
-static int for_all_interfaces(int (*doit) (struct interface *, void *),
- void *cookie)
-{
- struct interface *ife;
-
- if (!int_list) {
- int err = if_readlist();
- if (err < 0)
- return err;
- }
- for (ife = int_list; ife; ife = ife->next) {
- int err = doit(ife, cookie);
- if (err)
- return err;
- }
- return 0;
-}
-#endif
-
int FAST_FUNC display_interfaces(char *ifname)
{
struct interface *ife;
int res;
+ struct iface_list ilist;
+
+ ilist.int_list = NULL;
+ ilist.int_last = NULL;
+ if_readlist(&ilist, ifname != IFNAME_SHOW_DOWNED_TOO ? ifname : NULL);
if (!ifname || ifname == IFNAME_SHOW_DOWNED_TOO) {
- /*res = for_all_interfaces(do_if_print, &interface_opt_a);*/
- if (!int_list) {
- res = if_readlist();
- if (res < 0)
- goto ret;
- }
- for (ife = int_list; ife; ife = ife->next) {
+ for (ife = ilist.int_list; ife; ife = ife->next) {
+
BUILD_BUG_ON((int)(intptr_t)IFNAME_SHOW_DOWNED_TOO != 1);
+
res = do_if_print(ife, (int)(intptr_t)ifname);
if (res < 0)
goto ret;
@@ -1147,10 +1100,8 @@ int FAST_FUNC display_interfaces(char *ifname)
return 0;
}
- ife = lookup_interface(ifname);
- res = do_if_fetch(ife);
- if (res >= 0)
- ife_print(ife);
+ ife = add_interface(&ilist, ifname);
+ res = do_if_print(ife, /*show_downed_too:*/ 1);
ret:
return (res < 0); /* status < 0 == 1 -- error */
}
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