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Code Issues Releases Wiki Activity

Native properly compare sequence numbers

This commit is contained in:
M66B 2016-02-05 16:30:18 +01:00
parent 40985f9d93
commit 8b641422b5
2 changed files with 23 additions and 8 deletions
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29
app/src/main/jni/netguard/netguard.c
View File

@ -1924,7 +1924,7 @@ int check_dhcp(const struct arguments *args, const struct udp_session *u,
const uint8_t *data, const size_t datalen) {
// This is untested
// Android routing of DHCP is eroneous
// Android routing of DHCP is erroneous
log_android(ANDROID_LOG_WARN, "DHCP check");
@ -2204,17 +2204,17 @@ jboolean handle_tcp(const struct arguments *args,
if (datalen) {
uint32_t seq = ntohl(tcphdr->seq);
if (seq < cur->remote_seq)
if (compare_u16(seq, cur->remote_seq) < 0)
log_android(ANDROID_LOG_WARN, "%s already forwarded", session);
else {
struct segment *p = NULL;
struct segment *s = cur->data_rx;
while (s != NULL && s->seq < seq) {
while (s != NULL && compare_u16(s->seq, seq) < 0) {
p = s;
s = s->next;
}
if (s == NULL || s->seq > seq) {
if (s == NULL || compare_u16(s->seq, seq) > 0) {
struct segment *n = malloc(sizeof(struct segment));
n->seq = seq;
n->len = datalen;
@ -2231,8 +2231,7 @@ jboolean handle_tcp(const struct arguments *args,
if (s->len == datalen)
log_android(ANDROID_LOG_DEBUG, "%s already buffered", session);
else
log_android(ANDROID_LOG_ERROR,
"%s overlapping %u/%d",
log_android(ANDROID_LOG_ERROR, "%s overlapping %u/%d",
session, s->len, datalen);
}
}
@ -2364,7 +2363,7 @@ jboolean handle_tcp(const struct arguments *args,
}
}
else {
if (ntohl(tcphdr->ack_seq) < cur->local_seq) {
if (compare_u16(ntohl(tcphdr->ack_seq), cur->local_seq) < 0) {
log_android(ANDROID_LOG_WARN, "%s previous ACK", session);
return 1;
}
@ -2862,7 +2861,7 @@ ssize_t write_tcp(const struct arguments *args, const struct tcp_session *cur,
// Continue checksum
csum = calc_checksum(csum, (uint8_t *) tcp, sizeof(struct tcphdr));
csum = calc_checksum(csum, options, optlen);
csum = calc_checksum(csum, options, (size_t) optlen);
csum = calc_checksum(csum, data, datalen);
tcp->check = ~csum;
@ -3457,6 +3456,20 @@ void write_pcap(const void *ptr, size_t len) {
}
}
int compare_u16(uint16_t s1, uint16_t s2) {
// https://tools.ietf.org/html/rfc1982
if (s1 == s2)
return 0;
int i1 = s1;
int i2 = s2;
if ((i1 < i2 && i2 - i1 < 0x7FFF) ||
(i1 > i2 && i1 - i2 > 0x7FFF))
return -1;
else
return 1;
}
char *trim(char *str) {
while (isspace(*str))
str++;

2
app/src/main/jni/netguard/netguard.h
View File

@ -395,6 +395,8 @@ void write_pcap_rec(const uint8_t *buffer, size_t len);
void write_pcap(const void *ptr, size_t len);
int compare_u16(uint16_t seq1, uint16_t seq2);
const char *strstate(const int state);
char *hex(const u_int8_t *data, const size_t len);