aboutsummaryrefslogtreecommitdiffstats
path: root/lib/common.c
blob: 20ef29f01e1e0c109e85452b7d8e4842e829baed (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
#include "common.h"
#include <arpa/inet.h>
#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <regex.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>

int nfl_check_file(FILE *f) {
    struct stat s;
    assert(f);
    if (fstat(fileno(f), &s) < 0)
        return -errno;

    // Ignore file already unlinked
    if (s.st_nlink <= 0)
        return -EIDRM;

    return 0;
}

int nfl_check_dir(const char *storage_dir) {
    struct stat _d;
    if (stat(storage_dir, &_d) != 0 || !S_ISDIR(_d.st_mode)) {
        return -1;
    }
    return 0;
}

int nfl_storage_match_index(const char *fn) {
    static regex_t regex;
    static bool compiled = false;
    regmatch_t match[1];
    int ret;

    if(unlikely(!strcmp(fn, ".") || !strcmp(fn, "..")))
        return -1;

    if (!compiled) {
        ERR(regcomp(&regex, "^" STORAGE_PREFIX "_([0-9]+)", REG_EXTENDED),
            "Could not compile regex");
        compiled = true;
    }

    ret = regexec(&regex, fn, 2, match, 0);
    if (!ret) {
        assert(match[1].rm_so != (size_t)-1);
        return strtol(fn + match[1].rm_so, NULL, 10);
    } else {
        char buf[100];
        regerror(ret, &regex, buf, sizeof(buf));
        WARN(1, "Regex match failed: %s", buf)
    }

    return -1;
}
const char *nfl_get_filename(const char *dir, int id) {
    char out[1024];
    sprintf(out, "%s/" STORAGE_PREFIX "_%d", dir, id);
    return strdup(out);
}

uint32_t nfl_get_filesize(FILE *f) {
    uint32_t size, prepos;
    prepos = ftell(f);
    fseek(f, 0, SEEK_END);
    size = ftell(f);
    fseek(f, prepos, SEEK_SET);
    return size;
}

uint32_t nfl_header_cksum(nflog_header_t *header) {
    register uint64_t s = 3784672181;
    s += header->id;
    s ^= header->max_n_entries;
    s += header->n_entries;
    s ^= header->start_time;
    s += header->end_time;
    s &= UINT_MAX;
    return s;
}

void nfl_cal_trunk(uint32_t total_size, uint32_t *trunk_cnt,
                   uint32_t *trunk_size) {
    uint32_t pgsize = getpagesize();
    total_size *= 1024 * 1024; // MiB

    assert(trunk_cnt);
    assert(total_size);

    *trunk_cnt = CEIL_DIV(total_size, pgsize * TRUNK_SIZE_BY_PAGE);
    if (*trunk_cnt > MAX_TRUNK_ID) {
        *trunk_cnt = MAX_TRUNK_ID;
        *trunk_size = total_size / MAX_TRUNK_ID;
        *trunk_size = (*trunk_size / pgsize) * pgsize; // align with pagesize
    } else {
        *trunk_size = pgsize * TRUNK_SIZE_BY_PAGE;
    }
}

void nfl_cal_entries(uint32_t trunk_size, uint32_t *entries_cnt) {
    assert(entries_cnt);
    *entries_cnt =
        (trunk_size - sizeof(nflog_header_t)) / sizeof(nflog_entry_t);
}

void nfl_format_output(char *output, nflog_entry_t *entry) {
    sprintf(output, "t=%ld\t"
                    "daddr=%s\t"
                    "proto=%s\t"
                    "uid=%d\t"
                    "sport=%d\t"
                    "dport=%d",
            entry->timestamp, inet_ntoa(entry->daddr),
            entry->protocol == IPPROTO_TCP ? "TCP" : "UDP", entry->uid,
            entry->sport, entry->dport);
}

int nfl_setup_compression(const char *flag, enum nflog_compression_t *opt) {
    if (flag == NULL) {
        *opt = COMPRESS_NONE;
    } else if (!strcmp(flag, "zstd") || !strcmp(flag, "zstandard")) {
        *opt = COMPRESS_ZSTD;
    } else if (!strcmp(flag, "lz4")) {
        *opt = COMPRESS_LZ4;
    } else {
        fprintf(stderr, "Unknown compression algorithm: %s\n", flag);
        return 0;
    }

    return 1;
}