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8a5299fcf

Denys Vlasenko
Denys Vlasenko
2018-03-05
SUCCESS Duration: 147s

Subject

networking/interface.c: code shrink

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Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

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Commit Diff GitHub →

networking/interface.c +76 -61
networking/interface.c+76 -61
@@ -318,20 +318,27 @@ struct interface {
char name[IFNAMSIZ]; /* interface name */
short type; /* if type */
short flags; /* various flags */
+ int tx_queue_len; /* transmit queue length */
+
+ /* these should be contiguous, zeroed in one go in if_fetch(): */
+#define FIRST_TO_ZERO metric
int metric; /* routing metric */
int mtu; /* MTU value */
- int tx_queue_len; /* transmit queue length */
struct ifmap map; /* hardware setup */
struct sockaddr addr; /* IP address */
struct sockaddr dstaddr; /* P-P IP address */
struct sockaddr broadaddr; /* IP broadcast address */
struct sockaddr netmask; /* IP network mask */
- int has_ip;
char hwaddr[32]; /* HW address */
- int statistics_valid;
+#define LAST_TO_ZERO hwaddr
+
+ smallint has_ip;
+ smallint statistics_valid;
struct user_net_device_stats stats; /* statistics */
+#if 0 /* UNUSED */
int keepalive; /* keepalive value for SLIP */
int outfill; /* outfill value for SLIP */
+#endif
};
@@ -342,7 +349,7 @@ static struct interface *int_list, *int_last;
#if 0
/* like strcmp(), but knows about numbers */
-except that the freshly added calls to xatoul() brf on ethernet aliases with
+except that the freshly added calls to xatoul() barf on ethernet aliases with
uClibc with e.g.: ife->name='lo' name='eth0:1'
static int nstrcmp(const char *a, const char *b)
{
@@ -394,32 +401,31 @@ static struct interface *add_interface(char *name)
return new;
}
-static char *get_name(char *name, char *p)
+static char *get_name(char name[IFNAMSIZ], char *p)
{
- /* Extract <name> from nul-terminated p where p matches
- * <name>: after leading whitespace.
- * If match is not made, set name empty and return unchanged p
+ /* Extract NAME from nul-terminated p of the form "<whitespace>NAME:"
+ * If match is not made, set NAME to "" and return unchanged p.
*/
char *nameend;
- char *namestart = skip_whitespace(p);
+ char *namestart;
- nameend = namestart;
- while (*nameend && *nameend != ':' && !isspace(*nameend))
- nameend++;
- if (*nameend == ':') {
- if ((nameend - namestart) < IFNAMSIZ) {
+ nameend = namestart = skip_whitespace(p);
+
+ for (;;) {
+ if ((nameend - namestart) >= IFNAMSIZ)
+ break; /* interface name too large - return "" */
+ if (*nameend == ':') {
memcpy(name, namestart, nameend - namestart);
name[nameend - namestart] = '\0';
- p = nameend;
- } else {
- /* Interface name too large */
- name[0] = '\0';
+ return nameend + 1;
}
- } else {
- /* trailing ':' not found - return empty */
- name[0] = '\0';
+ nameend++;
+ /* isspace, NUL, any control char? */
+ if ((unsigned char)*nameend <= (unsigned char)' ')
+ break; /* trailing ':' not found - return "" */
}
- return p + 1;
+ name[0] = '\0';
+ return p;
}
/* If scanf supports size qualifiers for %n conversions, then we can
@@ -435,7 +441,10 @@ static char *get_name(char *name, char *p)
/* "%llu%llu%lu%lu%lu%lu%lu%lu%llu%llu%lu%lu%lu%lu%lu%lu" */
/* }; */
- /* Lie about the size of the int pointed to for %n. */
+/* We use %n for unavailable data in older versions of /proc/net/dev formats.
+ * This results in bogus stores to ife->FOO members corresponding to
+ * %n specifiers (even the size of integers may not match).
+ */
#if INT_MAX == LONG_MAX
static const char *const ss_fmt[] = {
"%n%llu%u%u%u%u%n%n%n%llu%u%u%u%u%u",
@@ -448,7 +457,6 @@ static const char *const ss_fmt[] = {
"%llu%llu%lu%lu%lu%lu%n%n%llu%llu%lu%lu%lu%lu%lu",
"%llu%llu%lu%lu%lu%lu%lu%lu%llu%llu%lu%lu%lu%lu%lu%lu"
};
-
#endif
static void get_dev_fields(char *bp, struct interface *ife, int procnetdev_vsn)
@@ -456,22 +464,22 @@ static void get_dev_fields(char *bp, struct interface *ife, int procnetdev_vsn)
memset(&ife->stats, 0, sizeof(struct user_net_device_stats));
sscanf(bp, ss_fmt[procnetdev_vsn],
- &ife->stats.rx_bytes, /* missing for 0 */
+ &ife->stats.rx_bytes, /* missing for v0 */
&ife->stats.rx_packets,
&ife->stats.rx_errors,
&ife->stats.rx_dropped,
&ife->stats.rx_fifo_errors,
&ife->stats.rx_frame_errors,
- &ife->stats.rx_compressed, /* missing for <= 1 */
- &ife->stats.rx_multicast, /* missing for <= 1 */
- &ife->stats.tx_bytes, /* missing for 0 */
+ &ife->stats.rx_compressed, /* missing for v0, v1 */
+ &ife->stats.rx_multicast, /* missing for v0, v1 */
+ &ife->stats.tx_bytes, /* missing for v0 */
&ife->stats.tx_packets,
&ife->stats.tx_errors,
&ife->stats.tx_dropped,
&ife->stats.tx_fifo_errors,
&ife->stats.collisions,
&ife->stats.tx_carrier_errors,
- &ife->stats.tx_compressed /* missing for <= 1 */
+ &ife->stats.tx_compressed /* missing for v0, v1 */
);
if (procnetdev_vsn <= 1) {
@@ -499,24 +507,21 @@ static int if_readconf(void)
int numreqs = 30;
struct ifconf ifc;
struct ifreq *ifr;
- int n, err = -1;
+ int n, err;
int skfd;
ifc.ifc_buf = NULL;
/* SIOCGIFCONF currently seems to only work properly on AF_INET sockets
(as of 2.1.128) */
- skfd = socket(AF_INET, SOCK_DGRAM, 0);
- if (skfd < 0) {
- bb_perror_msg("error: no inet socket available");
- return -1;
- }
+ skfd = xsocket(AF_INET, SOCK_DGRAM, 0);
for (;;) {
ifc.ifc_len = sizeof(struct ifreq) * numreqs;
ifc.ifc_buf = xrealloc(ifc.ifc_buf, ifc.ifc_len);
- if (ioctl_or_warn(skfd, SIOCGIFCONF, &ifc) < 0) {
+ err = ioctl_or_warn(skfd, SIOCGIFCONF, &ifc);
+ if (err < 0) {
goto out;
}
if (ifc.ifc_len == (int)(sizeof(struct ifreq) * numreqs)) {
@@ -565,7 +570,7 @@ static int if_readlist_proc(char *target)
err = 0;
while (fgets(buf, sizeof buf, fh)) {
- char *s, name[128];
+ char *s, name[IFNAMSIZ];
s = get_name(name, buf);
ife = add_interface(name);
@@ -574,11 +579,15 @@ static int if_readlist_proc(char *target)
if (target && strcmp(target, name) == 0)
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;
}
@@ -608,24 +617,29 @@ static int if_fetch(struct interface *ife)
}
ife->flags = ifr.ifr_flags;
+ /* set up default values if ioctl's would fail */
+ ife->tx_queue_len = -1; /* unknown value */
+ memset(&ife->FIRST_TO_ZERO, 0,
+ offsetof(struct interface, LAST_TO_ZERO)
+ - offsetof(struct interface, FIRST_TO_ZERO)
+ + sizeof(ife->LAST_TO_ZERO)
+ );
+
strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
- memset(ife->hwaddr, 0, 32);
if (ioctl(skfd, SIOCGIFHWADDR, &ifr) >= 0)
memcpy(ife->hwaddr, ifr.ifr_hwaddr.sa_data, 8);
+//er.... why this _isnt_ inside if()?
ife->type = ifr.ifr_hwaddr.sa_family;
strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
- ife->metric = 0;
if (ioctl(skfd, SIOCGIFMETRIC, &ifr) >= 0)
ife->metric = ifr.ifr_metric;
strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
- ife->mtu = 0;
if (ioctl(skfd, SIOCGIFMTU, &ifr) >= 0)
ife->mtu = ifr.ifr_mtu;
- memset(&ife->map, 0, sizeof(struct ifmap));
#ifdef SIOCGIFMAP
strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
if (ioctl(skfd, SIOCGIFMAP, &ifr) == 0)
@@ -634,31 +648,24 @@ static int if_fetch(struct interface *ife)
#ifdef HAVE_TXQUEUELEN
strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
- ife->tx_queue_len = -1; /* unknown value */
if (ioctl(skfd, SIOCGIFTXQLEN, &ifr) >= 0)
ife->tx_queue_len = ifr.ifr_qlen;
-#else
- ife->tx_queue_len = -1; /* unknown value */
#endif
strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
ifr.ifr_addr.sa_family = AF_INET;
- memset(&ife->addr, 0, sizeof(struct sockaddr));
if (ioctl(skfd, SIOCGIFADDR, &ifr) == 0) {
ife->has_ip = 1;
ife->addr = ifr.ifr_addr;
strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
- memset(&ife->dstaddr, 0, sizeof(struct sockaddr));
if (ioctl(skfd, SIOCGIFDSTADDR, &ifr) >= 0)
ife->dstaddr = ifr.ifr_dstaddr;
strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
- memset(&ife->broadaddr, 0, sizeof(struct sockaddr));
if (ioctl(skfd, SIOCGIFBRDADDR, &ifr) >= 0)
ife->broadaddr = ifr.ifr_broadaddr;
strncpy_IFNAMSIZ(ifr.ifr_name, ifname);
- memset(&ife->netmask, 0, sizeof(struct sockaddr));
if (ioctl(skfd, SIOCGIFNETMASK, &ifr) >= 0)
ife->netmask = ifr.ifr_netmask;
}
@@ -1020,9 +1027,11 @@ static void ife_print(struct interface *ptr)
/* DONT FORGET TO ADD THE FLAGS IN ife_print_short */
printf(" MTU:%d Metric:%d", ptr->mtu, ptr->metric ? ptr->metric : 1);
+#if 0
#ifdef SIOCSKEEPALIVE
if (ptr->outfill || ptr->keepalive)
printf(" Outfill:%d Keepalive:%d", ptr->outfill, ptr->keepalive);
+#endif
#endif
bb_putchar('\n');
@@ -1105,8 +1114,11 @@ static int for_all_interfaces(int (*doit) (struct interface *, void *),
{
struct interface *ife;
- if (!int_list && (if_readlist() < 0))
- return -1;
+ 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)
@@ -1124,8 +1136,11 @@ static int if_print(char *ifname)
if (!ifname) {
/*res = for_all_interfaces(do_if_print, &interface_opt_a);*/
- if (!int_list && (if_readlist() < 0))
- return -1;
+ if (!int_list) {
+ int err = if_readlist();
+ if (err < 0)
+ return err;
+ }
for (ife = int_list; ife; ife = ife->next) {
int err = do_if_print(ife); /*, &interface_opt_a);*/
if (err)
@@ -1140,6 +1155,15 @@ static int if_print(char *ifname)
return res;
}
+int FAST_FUNC display_interfaces(char *ifname)
+{
+ int status;
+
+ status = if_print(ifname);
+
+ return (status < 0); /* status < 0 == 1 -- error */
+}
+
#if ENABLE_FEATURE_HWIB
/* Input an Infiniband address and convert to binary. */
int FAST_FUNC in_ib(const char *bufp, struct sockaddr *sap)
@@ -1153,12 +1177,3 @@ int FAST_FUNC in_ib(const char *bufp, struct sockaddr *sap)
return 0;
}
#endif
-
-int FAST_FUNC display_interfaces(char *ifname)
-{
- int status;
-
- status = if_print(ifname);
-
- return (status < 0); /* status < 0 == 1 -- error */
-}