aboutsummaryrefslogtreecommitdiff
path: root/src/resolve-system-dependencies/resolve-system-dependencies.cc
blob: 4b2f55f09580923c6ce2c012e1222fd837662c2c (plain)
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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
#include "derivations.hh"
#include "globals.hh"
#include "shared.hh"
#include "store-api.hh"
#include <sys/utsname.h>
#include <algorithm>
#include <iostream>
#include <fstream>
#include <mach-o/loader.h>
#include <mach-o/swap.h>

using namespace nix;

static auto cacheDir = Path{};

Path resolveCacheFile(Path lib) {
    std::replace(lib.begin(), lib.end(), '/', '%');
    return cacheDir + "/" + lib;
}

std::set<string> readCacheFile(const Path & file) {
    return tokenizeString<set<string>>(readFile(file), "\n");
}

void writeCacheFile(const Path & file, std::set<string> & deps) {
    std::ofstream fp;
    fp.open(file);
    for (auto & d : deps) {
        fp << d << "\n";
    }
    fp.close();
}

std::string findDylibName(FILE *obj_file, struct load_command cmd) {
    fpos_t pos;
    fgetpos(obj_file, &pos);
    struct dylib_command dylc;
    dylc.cmd = cmd.cmd;
    dylc.cmdsize = cmd.cmdsize;
    fread(&dylc.dylib, sizeof(struct dylib), 1, obj_file);

    char *dylib_name = (char*)calloc(cmd.cmdsize, sizeof(char));
    fseek(obj_file,
            // offset is calculated from the beginning of the load command, which is two
            // uint32_t's backwards
            dylc.dylib.name.offset - (sizeof(uint32_t) * 2) + pos,
            SEEK_SET);
    fread(dylib_name, sizeof(char), cmd.cmdsize, obj_file);
    fseek(obj_file, pos, SEEK_SET);
    return std::string(dylib_name);
}

bool seekMach64Blob(FILE *obj_file, enum NXByteOrder end) {
    struct fat_header head;
    fread(&head, sizeof(struct fat_header), 1, obj_file);
    swap_fat_header(&head, end);
    for(uint32_t narches = 0; narches < head.nfat_arch; narches++) {
        struct fat_arch arch;
        fread(&arch, sizeof(struct fat_arch), 1, obj_file);
        swap_fat_arch(&arch, 1, end);
        if(arch.cputype == CPU_TYPE_X86_64) {
            fseek(obj_file, arch.offset, SEEK_SET);
            return true;
        }
    }
    return false;
}

std::set<std::string> runResolver(const Path & filename) {
    FILE *obj_file = fopen(filename.c_str(), "rb");
    uint32_t magic;
    fread(&magic, sizeof(uint32_t), 1, obj_file);
    fseek(obj_file, 0, SEEK_SET);
    enum NXByteOrder endianness;
    if(magic == 0xBEBAFECA) {
        endianness = NX_BigEndian;
        if(!seekMach64Blob(obj_file, endianness)) {
            std::cerr << "Could not find any mach64 blobs in file " << filename << ", continuing..." << std::endl;
            return std::set<string>();
        }
    }
    struct mach_header_64 header;
    fread(&header, sizeof(struct mach_header_64), 1, obj_file);
    if(!(header.magic == MH_MAGIC_64 || header.magic == MH_CIGAM_64)) {
        std::cerr << "Not a mach-o object file: " << filename << std::endl;
        return std::set<string>();
    }
    std::set<string> libs;
    for(uint32_t i = 0; i < header.ncmds; i++) {
        struct load_command cmd;
        fread(&cmd.cmd, sizeof(cmd.cmd), 1, obj_file);
        fread(&cmd.cmdsize, sizeof(cmd.cmdsize), 1, obj_file);
        switch(cmd.cmd) {
            case LC_LOAD_DYLIB:
            case LC_LOAD_UPWARD_DYLIB:
            case LC_REEXPORT_DYLIB:
                libs.insert(findDylibName(obj_file, cmd));
                break;
        }
        fseek(obj_file, cmd.cmdsize - (sizeof(uint32_t) * 2), SEEK_CUR);
    }
    fclose(obj_file);
    libs.erase(filename);
    return libs;
}

bool isSymlink(const Path & path) {
    struct stat st;
    if(lstat(path.c_str(), &st))
        throw SysError(format("getting attributes of path ‘%1%’") % path);

    return S_ISLNK(st.st_mode);
}

Path resolveSymlink(const Path & path) {
    char buf[PATH_MAX];
    ssize_t len = readlink(path.c_str(), buf, sizeof(buf) - 1);
    if(len != -1) {
        buf[len] = 0;
        return Path(buf);
    } else {
        throw SysError(format("readlink('%1%')") % path);
    }
}

std::set<string> resolveTree(const Path & path, PathSet & deps) {
    std::set<string> results;
    if(deps.find(path) != deps.end()) {
        return std::set<string>();
    }
    deps.insert(path);
    for (auto & lib : runResolver(path)) {
        results.insert(lib);
        for (auto & p : resolveTree(lib, deps)) {
            results.insert(p);
        }
    }
    return results;
}

std::set<string> getPath(const Path & path) {
    Path cacheFile = resolveCacheFile(path);
    if(pathExists(cacheFile)) {
        return readCacheFile(cacheFile);
    }

    std::set<string> deps;
    std::set<string> paths;
    paths.insert(path);

    Path next_path = Path(path);
    while(isSymlink(next_path)) {
        next_path = resolveSymlink(next_path);
        paths.insert(next_path);
    }

    for(auto & t : resolveTree(next_path, deps)) {
        paths.insert(t);
    }

    writeCacheFile(cacheFile, paths);

    return paths;
}

int main(int argc, char ** argv) {
    return handleExceptions(argv[0], [&]() {
            initNix();

            struct utsname _uname;

            uname(&_uname);

            auto cacheParentDir = (format("%1%/dependency-maps") % settings.nixStateDir).str();

            cacheDir = (format("%1%/%2%-%3%-%4%")
                    % cacheParentDir
                    % _uname.machine
                    % _uname.sysname
                    % _uname.release).str();

            mkdir(cacheParentDir.c_str(), 0755);
            mkdir(cacheDir.c_str(), 0755);

            auto store = openStore();

            auto drv = store->derivationFromPath(Path(argv[1]));
            Strings impurePaths = tokenizeString<Strings>(get(drv.env, "__impureHostDeps"));

            std::set<string> all_paths;

            for (auto & path : impurePaths) {
                for(auto & p : getPath(path)) {
                    all_paths.insert(p);
                }
            }

            std::cout << "extra-chroot-dirs" << std::endl;
            for(auto & path : all_paths) {
                std::cout << path << std::endl;
            }
            std::cout << std::endl;
    });
}