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Add simple length checks on UDP payload; use logger

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This commit is contained in:
Eric Wustrow 2013-08-16 17:43:02 -04:00
parent f891b7cdf2
commit b8246abf06
1 changed files with 22 additions and 7 deletions
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27
src/probe_modules/module_udp.c
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@ -25,6 +25,9 @@
#include "probe_modules.h" #include "probe_modules.h"
#include "packet.h" #include "packet.h"
#include "logger.h"
#define MAX_UDP_PAYLOAD_LEN 1472
char *udp_send_msg = NULL; // Must be null-terminated char *udp_send_msg = NULL; // Must be null-terminated
int udp_send_msg_len = 0; int udp_send_msg_len = 0;
@ -52,8 +55,9 @@ int udp_global_initialize(struct state_conf * zconf) {
args = strdup(zconf->probe_args); args = strdup(zconf->probe_args);
c = strchr(args, ':'); c = strchr(args, ':');
if (! c) { if (! c) {
fprintf(stderr, "error: unknown UDP probe specification (expected type:value, like file:/path or text:STRING or hex:01020304)\n");
free(args); free(args);
free(udp_send_msg);
log_fatal("udp", "unknown UDP probe specification (expected type:value, like file:/path or text:STRING or hex:01020304)");
exit(1); exit(1);
} }
@ -66,16 +70,19 @@ int udp_global_initialize(struct state_conf * zconf) {
} else if (strcmp(args, "file") == 0) { } else if (strcmp(args, "file") == 0) {
inp = fopen(c, "rb"); inp = fopen(c, "rb");
if (!inp) { if (!inp) {
fprintf(stderr, "error: could not open the specified file\n");
free(args); free(args);
free(udp_send_msg);
log_fatal("udp", "could not open UDP data file '%s'\n", c);
exit(1); exit(1);
} }
udp_send_msg = malloc(1472); udp_send_msg = malloc(MAX_UDP_PAYLOAD_LEN);
if (! udp_send_msg) { if (! udp_send_msg) {
free(args); free(args);
free(udp_send_msg);
log_fatal("udp", "failed to malloc payload buffer");
exit(1); exit(1);
} }
udp_send_msg_len = fread(udp_send_msg, 1, 1472, inp); udp_send_msg_len = fread(udp_send_msg, 1, MAX_UDP_PAYLOAD_LEN, inp);
fclose(inp); fclose(inp);
} else if (strcmp(args, "hex") == 0) { } else if (strcmp(args, "hex") == 0) {
@ -83,19 +90,27 @@ int udp_global_initialize(struct state_conf * zconf) {
udp_send_msg = malloc(udp_send_msg_len); udp_send_msg = malloc(udp_send_msg_len);
if (! udp_send_msg) { if (! udp_send_msg) {
free(args); free(args);
free(udp_send_msg);
log_fatal("udp", "failed to malloc payload buffer");
exit(1); exit(1);
} }
for (i=0; i < udp_send_msg_len; i++) { for (i=0; i < udp_send_msg_len; i++) {
sscanf(c + (i*2), "%2x", &n); if (sscanf(c + (i*2), "%2x", &n) != 1) {
free(args);
free(udp_send_msg);
log_fatal("udp", "non-hex character: '%c'", c[i*2]);
exit(1);
}
udp_send_msg[i] = (n & 0xff); udp_send_msg[i] = (n & 0xff);
} }
} else { } else {
fprintf(stderr, "error: unknown UDP probe specification (expected file:/path, text:STRING, or hex:01020304)\n"); log_fatal("udp", "unknown UDP probe specification (expected file:/path, text:STRING, or hex:01020304)");
free(args); free(args);
exit(1); exit(1);
} }
assert(udp_send_msg_len < MAX_UDP_PAYLOAD_LEN);
free(args); free(args);
return(0); return(0);
} }