networking/interface.c: get rid of global data

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@googlemail.com>
This commit is contained in:
Denys Vlasenko 2018-03-05 18:28:04 +01:00
parent 82ec89480d
commit d51ba0b5ab

View File

@ -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 */
}