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Diffstat (limited to 'networking/arp.c')
-rw-r--r--networking/arp.c132
1 files changed, 65 insertions, 67 deletions
diff --git a/networking/arp.c b/networking/arp.c
index 2af6bc970..7a36f44bb 100644
--- a/networking/arp.c
+++ b/networking/arp.c
@@ -27,8 +27,6 @@
#define DFLT_AF "inet"
#define DFLT_HW "ether"
-#define _PATH_PROCNET_ARP "/proc/net/arp"
-
#define ARP_OPT_A (0x1)
#define ARP_OPT_p (0x2)
#define ARP_OPT_H (0x4)
@@ -64,7 +62,7 @@ static const char *const options[] = {
/* Called only from main, once */
static int arp_del(char **args)
{
- char host[128];
+ char *host;
struct arpreq req;
struct sockaddr sa;
int flags = 0;
@@ -73,8 +71,8 @@ static int arp_del(char **args)
memset(&req, 0, sizeof(req));
/* Resolve the host name. */
- safe_strncpy(host, *args, 128);
- if (ap->input(0, host, &sa) < 0) {
+ host = *args;
+ if (ap->input(host, &sa) < 0) {
bb_herror_msg_and_die("%s", host);
}
@@ -130,8 +128,8 @@ static int arp_del(char **args)
if (*++args == NULL)
bb_show_usage();
if (strcmp(*args, "255.255.255.255") != 0) {
- safe_strncpy(host, *args, 128);
- if (ap->input(0, host, &sa) < 0) {
+ host = *args;
+ if (ap->input(host, &sa) < 0) {
bb_herror_msg_and_die("%s", host);
}
memcpy(&req.arp_netmask, &sa, sizeof(struct sockaddr));
@@ -213,15 +211,15 @@ static void arp_getdevhw(char *ifname, struct sockaddr *sa,
/* Called only from main, once */
static int arp_set(char **args)
{
- char host[128];
+ char *host;
struct arpreq req;
struct sockaddr sa;
int flags;
memset(&req, 0, sizeof(req));
- safe_strncpy(host, *args++, 128);
- if (ap->input(0, host, &sa) < 0) {
+ host = *args++;
+ if (ap->input(host, &sa) < 0) {
bb_herror_msg_and_die("%s", host);
}
/* If a host has more than one address, use the correct one! */
@@ -285,8 +283,8 @@ static int arp_set(char **args)
if (*++args == NULL)
bb_show_usage();
if (strcmp(*args, "255.255.255.255") != 0) {
- safe_strncpy(host, *args++, 128);
- if (ap->input(0, host, &sa) < 0) {
+ host = *args;
+ if (ap->input(host, &sa) < 0) {
bb_herror_msg_and_die("%s", host);
}
memcpy(&req.arp_netmask, &sa, sizeof(struct sockaddr));
@@ -362,82 +360,82 @@ arp_disp(const char *name, char *ip, int type, int arp_flags,
/* Called only from main, once */
static int arp_show(char *name)
{
- char host[100];
+ const char *host;
+ const char *hostname;
+ FILE *fp;
struct sockaddr sa;
- char ip[100];
- char hwa[100];
- char mask[100];
- char line[200];
- char dev[100];
int type, flags;
- FILE *fp;
- const char *hostname;
int num;
unsigned entries = 0, shown = 0;
+ char ip[128];
+ char hwa[128];
+ char mask[128];
+ char line[128];
+ char dev[128];
- host[0] = '\0';
-
+ host = NULL;
if (name != NULL) {
/* Resolve the host name. */
- safe_strncpy(host, name, (sizeof host));
- if (ap->input(0, host, &sa) < 0) {
- bb_herror_msg_and_die("%s", host);
+ if (ap->input(name, &sa) < 0) {
+ bb_herror_msg_and_die("%s", name);
}
- safe_strncpy(host, ap->sprint(&sa, 1), sizeof(host));
+ host = xstrdup(ap->sprint(&sa, 1));
}
- /* Open the PROCps kernel table. */
- fp = xfopen(_PATH_PROCNET_ARP, "r");
- /* Bypass header -- read until newline */
- if (fgets(line, sizeof(line), fp) != (char *) NULL) {
+ fp = xfopen("/proc/net/arp", "r");
+ /* Bypass header -- read one line */
+ fgets(line, sizeof(line), fp);
+
+ /* Read the ARP cache entries. */
+ while (fgets(line, sizeof(line), fp)) {
+
mask[0] = '-'; mask[1] = '\0';
dev[0] = '-'; dev[1] = '\0';
- /* Read the ARP cache entries. */
- for (; fgets(line, sizeof(line), fp);) {
- num = sscanf(line, "%s 0x%x 0x%x %100s %100s %100s\n",
- ip, &type, &flags, hwa, mask, dev);
- if (num < 4)
- break;
-
- entries++;
- /* if the user specified hw-type differs, skip it */
- if (hw_set && (type != hw->type))
- continue;
-
- /* if the user specified address differs, skip it */
- if (host[0] && strcmp(ip, host) != 0)
- continue;
-
- /* if the user specified device differs, skip it */
- if (device[0] && strcmp(dev, device) != 0)
- continue;
-
- shown++;
- /* This IS ugly but it works -be */
- if (option_mask32 & ARP_OPT_n)
- hostname = "?";
- else {
- if (ap->input(0, ip, &sa) < 0)
- hostname = ip;
- else
- hostname = ap->sprint(&sa, (option_mask32 & ARP_OPT_n) | 0x8000);
- if (strcmp(hostname, ip) == 0)
- hostname = "?";
- }
+ /* All these strings can't overflow
+ * because fgets above reads limited amount of data */
+ num = sscanf(line, "%s 0x%x 0x%x %s %s %s\n",
+ ip, &type, &flags, hwa, mask, dev);
+ if (num < 4)
+ break;
- arp_disp(hostname, ip, type, flags, hwa, mask, dev);
+ entries++;
+ /* if the user specified hw-type differs, skip it */
+ if (hw_set && (type != hw->type))
+ continue;
+
+ /* if the user specified address differs, skip it */
+ if (host && strcmp(ip, host) != 0)
+ continue;
+
+ /* if the user specified device differs, skip it */
+ if (device[0] && strcmp(dev, device) != 0)
+ continue;
+
+ shown++;
+ /* This IS ugly but it works -be */
+ hostname = "?";
+ if (!(option_mask32 & ARP_OPT_n)) {
+ if (ap->input(ip, &sa) < 0)
+ hostname = ip;
+ else
+ hostname = ap->sprint(&sa, (option_mask32 & ARP_OPT_n) | 0x8000);
+ if (strcmp(hostname, ip) == 0)
+ hostname = "?";
}
+
+ arp_disp(hostname, ip, type, flags, hwa, mask, dev);
}
if (option_mask32 & ARP_OPT_v)
printf("Entries: %d\tSkipped: %d\tFound: %d\n",
entries, entries - shown, shown);
if (!shown) {
- if (hw_set || host[0] || device[0])
+ if (hw_set || host || device[0])
printf("No match found in %d entries\n", entries);
}
-
- fclose(fp);
-
+ if (ENABLE_FEATURE_CLEAN_UP) {
+ free((char*)host);
+ fclose(fp);
+ }
return 0;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 18:38:44 +0000