sumversion.c

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#include <netinet/in.h>
#ifdef __sun__
#include <inttypes.h>
#else
#include <stdint.h>
#endif
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include <limits.h>
#include "modpost.h"

/*
 * Stolen form Cryptographic API.
 *
 * MD4 Message Digest Algorithm (RFC1320).
 *
 * Implementation derived from Andrew Tridgell and Steve French's
 * CIFS MD4 implementation, and the cryptoapi implementation
 * originally based on the public domain implementation written
 * by Colin Plumb in 1993.
 *
 * Copyright (c) Andrew Tridgell 1997-1998.
 * Modified by Steve French ([email protected]) 2002
 * Copyright (c) Cryptoapi developers.
 * Copyright (c) 2002 David S. Miller ([email protected])
 * Copyright (c) 2002 James Morris <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 */
#define MD4_DIGEST_SIZE     16
#define MD4_HMAC_BLOCK_SIZE 64
#define MD4_BLOCK_WORDS     16
#define MD4_HASH_WORDS      4

struct md4_ctx {
    uint32_t hash[MD4_HASH_WORDS];
    uint32_t block[MD4_BLOCK_WORDS];
    uint64_t byte_count;
};

static inline uint32_t lshift(uint32_t x, unsigned int s)
{
    x &= 0xFFFFFFFF;
    return ((x << s) & 0xFFFFFFFF) | (x >> (32 - s));
}

static inline uint32_t F(uint32_t x, uint32_t y, uint32_t z)
{
    return (x & y) | ((~x) & z);
}

static inline uint32_t G(uint32_t x, uint32_t y, uint32_t z)
{
    return (x & y) | (x & z) | (y & z);
}

static inline uint32_t H(uint32_t x, uint32_t y, uint32_t z)
{
    return x ^ y ^ z;
}

#define ROUND1(a,b,c,d,k,s) (a = lshift(a + F(b,c,d) + k, s))
#define ROUND2(a,b,c,d,k,s) (a = lshift(a + G(b,c,d) + k + (uint32_t)0x5A827999,s))
#define ROUND3(a,b,c,d,k,s) (a = lshift(a + H(b,c,d) + k + (uint32_t)0x6ED9EBA1,s))

/* XXX: this stuff can be optimized */
static inline void le32_to_cpu_array(uint32_t *buf, unsigned int words)
{
    while (words--) {
        *buf = ntohl(*buf);
        buf++;
    }
}

static inline void cpu_to_le32_array(uint32_t *buf, unsigned int words)
{
    while (words--) {
        *buf = htonl(*buf);
        buf++;
    }
}

static void md4_transform(uint32_t *hash, uint32_t const *in)
{
    uint32_t a, b, c, d;

    a = hash[0];
    b = hash[1];
    c = hash[2];
    d = hash[3];

    ROUND1(a, b, c, d, in[0], 3);
    ROUND1(d, a, b, c, in[1], 7);
    ROUND1(c, d, a, b, in[2], 11);
    ROUND1(b, c, d, a, in[3], 19);
    ROUND1(a, b, c, d, in[4], 3);
    ROUND1(d, a, b, c, in[5], 7);
    ROUND1(c, d, a, b, in[6], 11);
    ROUND1(b, c, d, a, in[7], 19);
    ROUND1(a, b, c, d, in[8], 3);
    ROUND1(d, a, b, c, in[9], 7);
    ROUND1(c, d, a, b, in[10], 11);
    ROUND1(b, c, d, a, in[11], 19);
    ROUND1(a, b, c, d, in[12], 3);
    ROUND1(d, a, b, c, in[13], 7);
    ROUND1(c, d, a, b, in[14], 11);
    ROUND1(b, c, d, a, in[15], 19);

    ROUND2(a, b, c, d,in[ 0], 3);
    ROUND2(d, a, b, c, in[4], 5);
    ROUND2(c, d, a, b, in[8], 9);
    ROUND2(b, c, d, a, in[12], 13);
    ROUND2(a, b, c, d, in[1], 3);
    ROUND2(d, a, b, c, in[5], 5);
    ROUND2(c, d, a, b, in[9], 9);
    ROUND2(b, c, d, a, in[13], 13);
    ROUND2(a, b, c, d, in[2], 3);
    ROUND2(d, a, b, c, in[6], 5);
    ROUND2(c, d, a, b, in[10], 9);
    ROUND2(b, c, d, a, in[14], 13);
    ROUND2(a, b, c, d, in[3], 3);
    ROUND2(d, a, b, c, in[7], 5);
    ROUND2(c, d, a, b, in[11], 9);
    ROUND2(b, c, d, a, in[15], 13);

    ROUND3(a, b, c, d,in[ 0], 3);
    ROUND3(d, a, b, c, in[8], 9);
    ROUND3(c, d, a, b, in[4], 11);
    ROUND3(b, c, d, a, in[12], 15);
    ROUND3(a, b, c, d, in[2], 3);
    ROUND3(d, a, b, c, in[10], 9);
    ROUND3(c, d, a, b, in[6], 11);
    ROUND3(b, c, d, a, in[14], 15);
    ROUND3(a, b, c, d, in[1], 3);
    ROUND3(d, a, b, c, in[9], 9);
    ROUND3(c, d, a, b, in[5], 11);
    ROUND3(b, c, d, a, in[13], 15);
    ROUND3(a, b, c, d, in[3], 3);
    ROUND3(d, a, b, c, in[11], 9);
    ROUND3(c, d, a, b, in[7], 11);
    ROUND3(b, c, d, a, in[15], 15);

    hash[0] += a;
    hash[1] += b;
    hash[2] += c;
    hash[3] += d;
}

static inline void md4_transform_helper(struct md4_ctx *ctx)
{
    le32_to_cpu_array(ctx->block, sizeof(ctx->block) / sizeof(uint32_t));
    md4_transform(ctx->hash, ctx->block);
}

static void md4_init(struct md4_ctx *mctx)
{
    mctx->hash[0] = 0x67452301;
    mctx->hash[1] = 0xefcdab89;
    mctx->hash[2] = 0x98badcfe;
    mctx->hash[3] = 0x10325476;
    mctx->byte_count = 0;
}

static void md4_update(struct md4_ctx *mctx,
               const unsigned char *data, unsigned int len)
{
    const uint32_t avail = sizeof(mctx->block) - (mctx->byte_count & 0x3f);

    mctx->byte_count += len;

    if (avail > len) {
        memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
               data, len);
        return;
    }

    memcpy((char *)mctx->block + (sizeof(mctx->block) - avail),
           data, avail);

    md4_transform_helper(mctx);
    data += avail;
    len -= avail;

    while (len >= sizeof(mctx->block)) {
        memcpy(mctx->block, data, sizeof(mctx->block));
        md4_transform_helper(mctx);
        data += sizeof(mctx->block);
        len -= sizeof(mctx->block);
    }

    memcpy(mctx->block, data, len);
}

static void md4_final_ascii(struct md4_ctx *mctx, char *out, unsigned int len)
{
    const unsigned int offset = mctx->byte_count & 0x3f;
    char *p = (char *)mctx->block + offset;
    int padding = 56 - (offset + 1);

    *p++ = 0x80;
    if (padding < 0) {
        memset(p, 0x00, padding + sizeof (uint64_t));
        md4_transform_helper(mctx);
        p = (char *)mctx->block;
        padding = 56;
    }

    memset(p, 0, padding);
    mctx->block[14] = mctx->byte_count << 3;
    mctx->block[15] = mctx->byte_count >> 29;
    le32_to_cpu_array(mctx->block, (sizeof(mctx->block) -
                      sizeof(uint64_t)) / sizeof(uint32_t));
    md4_transform(mctx->hash, mctx->block);
    cpu_to_le32_array(mctx->hash, sizeof(mctx->hash) / sizeof(uint32_t));

    snprintf(out, len, "%08X%08X%08X%08X",
         mctx->hash[0], mctx->hash[1], mctx->hash[2], mctx->hash[3]);
}

static inline void add_char(unsigned char c, struct md4_ctx *md)
{
    md4_update(md, &c, 1);
}

static int parse_string(const char *file, unsigned long len,
            struct md4_ctx *md)
{
    unsigned long i;

    add_char(file[0], md);
    for (i = 1; i < len; i++) {
        add_char(file[i], md);
        if (file[i] == '"' && file[i-1] != '\\')
            break;
    }
    return i;
}

static int parse_comment(const char *file, unsigned long len)
{
    unsigned long i;

    for (i = 2; i < len; i++) {
        if (file[i-1] == '*' && file[i] == '/')
            break;
    }
    return i;
}

/* FIXME: Handle .s files differently (eg. # starts comments) --RR */
static int parse_file(const char *fname, struct md4_ctx *md)
{
    char *file;
    unsigned long i, len;

    file = grab_file(fname, &len);
    if (!file)
        return 0;

    for (i = 0; i < len; i++) {
        /* Collapse and ignore \ and CR. */
        if (file[i] == '\\' && (i+1 < len) && file[i+1] == '\n') {
            i++;
            continue;
        }

        /* Ignore whitespace */
        if (isspace(file[i]))
            continue;

        /* Handle strings as whole units */
        if (file[i] == '"') {
            i += parse_string(file+i, len - i, md);
            continue;
        }

        /* Comments: ignore */
        if (file[i] == '/' && file[i+1] == '*') {
            i += parse_comment(file+i, len - i);
            continue;
        }

        add_char(file[i], md);
    }
    release_file(file, len);
    return 1;
}
/* Check whether the file is a static library or not */
static int is_static_library(const char *objfile)
{
    int len = strlen(objfile);
    if (objfile[len - 2] == '.' && objfile[len - 1] == 'a')
        return 1;
    else
        return 0;
}

/* We have dir/file.o.  Open dir/.file.o.cmd, look for source_ and deps_ line
 * to figure out source files. */
static int parse_source_files(const char *objfile, struct md4_ctx *md)
{
    char *cmd, *file, *line, *dir;
    const char *base;
    unsigned long flen, pos = 0;
    int dirlen, ret = 0, check_files = 0;

    cmd = NOFAIL(malloc(strlen(objfile) + sizeof("..cmd")));

    base = strrchr(objfile, '/');
    if (base) {
        base++;
        dirlen = base - objfile;
        sprintf(cmd, "%.*s.%s.cmd", dirlen, objfile, base);
    } else {
        dirlen = 0;
        sprintf(cmd, ".%s.cmd", objfile);
    }
    dir = NOFAIL(malloc(dirlen + 1));
    strncpy(dir, objfile, dirlen);
    dir[dirlen] = '\0';

    file = grab_file(cmd, &flen);
    if (!file) {
        warn("could not find %s for %s\n", cmd, objfile);
        goto out;
    }

    /* There will be a line like so:
        deps_drivers/net/dummy.o := \
          drivers/net/dummy.c \
            $(wildcard include/config/net/fastroute.h) \
          include/linux/module.h \

       Sum all files in the same dir or subdirs.
    */
    while ((line = get_next_line(&pos, file, flen)) != NULL) {
        char* p = line;

        if (strncmp(line, "source_", sizeof("source_")-1) == 0) {
            p = strrchr(line, ' ');
            if (!p) {
                warn("malformed line: %s\n", line);
                goto out_file;
            }
            p++;
            if (!parse_file(p, md)) {
                warn("could not open %s: %s\n",
                     p, strerror(errno));
                goto out_file;
            }
            continue;
        }
        if (strncmp(line, "deps_", sizeof("deps_")-1) == 0) {
            check_files = 1;
            continue;
        }
        if (!check_files)
            continue;

        /* Continue until line does not end with '\' */
        if ( *(p + strlen(p)-1) != '\\')
            break;
        /* Terminate line at first space, to get rid of final ' \' */
        while (*p) {
                       if (isspace(*p)) {
                *p = '\0';
                break;
            }
            p++;
        }

        /* Check if this file is in same dir as objfile */
        if ((strstr(line, dir)+strlen(dir)-1) == strrchr(line, '/')) {
            if (!parse_file(line, md)) {
                warn("could not open %s: %s\n",
                     line, strerror(errno));
                goto out_file;
            }

        }

    }

    /* Everyone parsed OK */
    ret = 1;
out_file:
    release_file(file, flen);
out:
    free(dir);
    free(cmd);
    return ret;
}

/* Calc and record src checksum. */
void get_src_version(const char *modname, char sum[], unsigned sumlen)
{
    void *file;
    unsigned long len;
    struct md4_ctx md;
    char *sources, *end, *fname;
    const char *basename;
    char filelist[PATH_MAX + 1];
    char *modverdir = getenv("MODVERDIR");

    if (!modverdir)
        modverdir = ".";

    /* Source files for module are in .tmp_versions/modname.mod,
       after the first line. */
    if (strrchr(modname, '/'))
        basename = strrchr(modname, '/') + 1;
    else
        basename = modname;
    sprintf(filelist, "%s/%.*s.mod", modverdir,
        (int) strlen(basename) - 2, basename);

    file = grab_file(filelist, &len);
    if (!file)
        /* not a module or .mod file missing - ignore */
        return;

    sources = strchr(file, '\n');
    if (!sources) {
        warn("malformed versions file for %s\n", modname);
        goto release;
    }

    sources++;
    end = strchr(sources, '\n');
    if (!end) {
        warn("bad ending versions file for %s\n", modname);
        goto release;
    }
    *end = '\0';

    md4_init(&md);
    while ((fname = strsep(&sources, " ")) != NULL) {
        if (!*fname)
            continue;
        if (!(is_static_library(fname)) &&
                !parse_source_files(fname, &md))
            goto release;
    }

    md4_final_ascii(&md, sum, sumlen);
release:
    release_file(file, len);
}

static void write_version(const char *filename, const char *sum,
              unsigned long offset)
{
    int fd;

    fd = open(filename, O_RDWR);
    if (fd < 0) {
        warn("changing sum in %s failed: %s\n",
            filename, strerror(errno));
        return;
    }

    if (lseek(fd, offset, SEEK_SET) == (off_t)-1) {
        warn("changing sum in %s:%lu failed: %s\n",
            filename, offset, strerror(errno));
        goto out;
    }

    if (write(fd, sum, strlen(sum)+1) != strlen(sum)+1) {
        warn("writing sum in %s failed: %s\n",
            filename, strerror(errno));
        goto out;
    }
out:
    close(fd);
}

static int strip_rcs_crap(char *version)
{
    unsigned int len, full_len;

    if (strncmp(version, "$Revision", strlen("$Revision")) != 0)
        return 0;

    /* Space for version string follows. */
    full_len = strlen(version) + strlen(version + strlen(version) + 1) + 2;

    /* Move string to start with version number: prefix will be
     * $Revision$ or $Revision: */
    len = strlen("$Revision");
    if (version[len] == ':' || version[len] == '$')
        len++;
    while (isspace(version[len]))
        len++;
    memmove(version, version+len, full_len-len);
    full_len -= len;

    /* Preserve up to next whitespace. */
    len = 0;
    while (version[len] && !isspace(version[len]))
        len++;
    memmove(version + len, version + strlen(version),
        full_len - strlen(version));
    return 1;
}

/* Clean up RCS-style version numbers. */
void maybe_frob_rcs_version(const char *modfilename,
                char *version,
                void *modinfo,
                unsigned long version_offset)
{
    if (strip_rcs_crap(version))
        write_version(modfilename, version, version_offset);
}