platform_unix.c

/**
 * MojoPatch; a tool for updating data in the field.
 *
 * Please see the file LICENSE.txt in the source's root directory.
 *
 *  This file written by Ryan C. Gordon.
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <sys/param.h>
#include <errno.h>
#include <assert.h>
#include <sys/wait.h>

#if USE_PTHREAD
#include <pthread.h>
#endif

#include "platform.h"
#include "ui.h"

int file_exists(const char *fname)
{
    struct stat statbuf;
    return(stat(fname, &statbuf) == 0);
} /* file_exists */

int file_is_directory(const char *fname)
{
    struct stat statbuf;
    int retval = 0;

    if (stat(fname, &statbuf) == 0)
    {
        if (S_ISDIR(statbuf.st_mode))
            retval = 1;
    } /* if */
    
    return(retval);
} /* file_is_directory */


int file_is_symlink(const char *fname)
{
    struct stat statbuf;
    int retval = 0;

    if (lstat(fname, &statbuf) == 0)
    {
        if (S_ISLNK(statbuf.st_mode))
            retval = 1;
    } /* if */

    return(retval);
} /* file_is_symlink */


/* enumerate contents of (base) directory. */
file_list *make_filelist(const char *base)
{
    file_list *retval = NULL;
    file_list *l = NULL;
    file_list *prev = NULL;
    DIR *dir;
    struct dirent *ent;

    errno = 0;
    dir = opendir(base);
    if (dir == NULL)
    {
        _fatal("Error: could not read dir %s: %s.", base, strerror(errno));
        return(NULL);
    } /* if */

    while (1)
    {
        ent = readdir(dir);
        if (ent == NULL)   /* we're done. */
            break;

        if (strcmp(ent->d_name, ".") == 0)
            continue;

        if (strcmp(ent->d_name, "..") == 0)
            continue;

        /*
         * !!! FIXME: This is a workaround until symlinks are really
         * !!! FIXME:  supported...just pretend they don't exist for now.  :(
         */
        {
            char buf[MAXPATHLEN];
            snprintf(buf, sizeof (buf), "%s/%s", base, ent->d_name);
            if (file_is_symlink(buf))
                continue;
        }

        l = (file_list *) malloc(sizeof (file_list));
        if (l == NULL)
        {
            _fatal("Error: out of memory.");
            break;
        } /* if */

        l->fname = (char *) malloc(strlen(ent->d_name) + 1);
        if (l->fname == NULL)
        {
            free(l);
            _fatal("Error: out of memory.");
            break;
        } /* if */

        strcpy(l->fname, ent->d_name);

        if (retval == NULL)
            retval = l;
        else
            prev->next = l;

        prev = l;
        l->next = NULL;
    } /* while */

    closedir(dir);
    return(retval);
} /* make_filelist */


int get_file_size(const char *fname, unsigned int *fsize)
{
    struct stat statbuf;

    assert(fsize != NULL);

    if (stat(fname, &statbuf) == -1)
    {
        _fatal("Error: failed to get filesize of [%s]: %s.",
                fname, strerror(errno));
        return(0);
    } /* if */

    *fsize = statbuf.st_size;
    return(1);
} /* get_file_size */


char *get_realpath(const char *path)
{
    char resolved_path[MAXPATHLEN];
    char *retval = NULL;

    errno = 0;
    if (!realpath(path, resolved_path))
    {
        _fatal("Can't determine full path of [%s]: %s.",
                path, strerror(errno));
        return(NULL);
    } /* if */

    retval = malloc(strlen(resolved_path) + 1);
    if (retval == NULL)
    {
        _fatal("Error: out of memory.");
        return(NULL);
    } /* if */

    strcpy(retval, resolved_path);
    return(retval);
} /* get_realpath */


#if PLATFORM_MACOSX
#include <ApplicationServices/ApplicationServices.h>

static char *parse_xml(char *ptr, char **tag, char **val)
{
    char *ptr2;
    while ( (ptr = strchr(ptr, '<')) != NULL )
    {
        ptr++;  /* skip past '<' to start of tag.*/
        if (*ptr == '/') continue;  /* prior endtag? */
        if (*ptr == '!') continue;  /* initial crap? */
        if (*ptr == '?') continue;  /* initial crap? */

        *tag = ptr;
        *(ptr-1) = '/';  /* prepend a '/' so we can search for the endtag. */
        ptr2 = strchr(ptr, ' '); /* look for a space (tag attributes?) */
        if ( (ptr = strchr(ptr, '>')) == NULL ) return(NULL);
        if ((ptr2) && (ptr2 < ptr)) *ptr2 = '\0';  /* chop out attributes. */
        *ptr = '\0';  /* chop off '<' at end of tag. */
        *val = ptr + 1;  /* (*val) == start of children of this tag. */

        /* Catch <tagname/> tags... */
        ptr2 = ptr - 1;
        while ( (ptr2 != *tag) && (isspace(*ptr2)) )
            ptr2--;

        if ((ptr2 != *tag) && (*ptr2 == '/'))  /* it's a <tag/> ... skip it. */
        {
            ptr = *val;
            continue;
        } /* if */

        /* look for endtag... */
        ptr++;
        while ( (ptr = strstr(ptr, (*tag)-1)) != NULL )
        {
            if (*(ptr-1) != '<') { ptr++; continue; }  /* false positive */
            *(ptr-1) = '\0';  /* null-terminate tag's children. */
            break;
        } /* while */

        /* return everything after this tag's children. */
        return((ptr == NULL) ? NULL : ptr + 1);
    } /* while */

    return(NULL);
} /* parse_xml */


static char *find_info_plist_version(char *ptr)
{
    int have_key = 0;
    char *tag;
    char *val;

    while ( (ptr = parse_xml(ptr, &tag, &val)) != NULL )
    {
        if (have_key)
        {
            have_key = 0;
            if (strcasecmp(tag, "string") == 0)
                return(val);
        } /* if */

        if ((strcasecmp(tag, "plist") == 0) || (strcasecmp(tag, "dict") == 0))
        {
            ptr = val;
            continue;
        } /* if */

        /* You should only use CFBundleShortVersionString, for various
         *  reasons not worth explaining here. CFBundleVersion is here
         *  for older products that need to update to the other tag.
         */
        if (strcasecmp(tag,"key") == 0)
        {
            if (strcasecmp(val,"CFBundleVersion") == 0)
                have_key = 1;
            if (strcasecmp(val,"CFBundleShortVersionString") == 0)
                have_key = 1;
        } /* if */
    } /* while */
    
    return(NULL);
} /* find_info_plist_version */


/* !!! FIXME: Code duplication */
static char *find_info_plist_bundle_id(char *ptr)
{
    int have_key = 0;
    char *tag;
    char *val;

    while ( (ptr = parse_xml(ptr, &tag, &val)) != NULL )
    {
        if (have_key)
        {
            have_key = 0;
            if (strcasecmp(tag, "string") == 0)
                return(val);
        } /* if */

        if ((strcasecmp(tag, "plist") == 0) || (strcasecmp(tag, "dict") == 0))
        {
            ptr = val;
            continue;
        } /* if */

        if (strcasecmp(tag,"key") == 0)
        {
            if (strcasecmp(val,"CFBundleIdentifier") == 0)
                have_key = 1;
        } /* if */
    } /* while */
    
    return(NULL);
} /* find_info_plist_version */
#endif  /* PLATFORM_MACOSX */


/* you are already chdir()'d when this is called. */
int get_product_version(const char *ident, char *buf, size_t bufsize)
{
#if PLATFORM_MACOSX
    const char *fname = "Contents/Info.plist";  /* already chdir'd for this. */
    char *mem = NULL;
    char *ptr;
    unsigned int fsize;
    int retval = 0;
    FILE *io = NULL;

    if ( !get_file_size(fname, &fsize) ) goto parse_info_plist_bailed;
    if ( (mem = malloc(fsize + 1)) == NULL ) goto parse_info_plist_bailed;
    if ( (io = fopen(fname, "r")) == NULL ) goto parse_info_plist_bailed;
    if ( (fread(mem, fsize, 1, io)) != 1 ) goto parse_info_plist_bailed;
    fclose(io);
    io = NULL;
    mem[fsize] = '\0';

    if (ident != NULL)
    {
        ptr = find_info_plist_bundle_id(mem);
        if ((ptr == NULL) || (strcasecmp(ptr, ident) != 0))
        {
            int yes = ui_prompt_ny("We don't think we're looking at the right directory!"
                                   " Are you SURE this is the right place?"
                                   " If you aren't sure, clicking 'Yes' can destroy unrelated files!");
            if (!yes)
            {
                _fatal("Stopping at user's request.");
                free(mem);
                return(0);
            } /* if */
        } /* if */
    } /* if */

    /* !!! FIXME: this is kinda a lame hack. */
    if ( (io = fopen(fname, "r")) == NULL ) goto parse_info_plist_bailed;
    if ( (fread(mem, fsize, 1, io)) != 1 ) goto parse_info_plist_bailed;
    fclose(io);

    ptr = find_info_plist_version(mem);
    if (ptr == NULL)
        return(0);

    strncpy(buf, ptr, bufsize);
    buf[bufsize-1] = '\0';
    retval = 1;

parse_info_plist_bailed:
    free(mem);
    if (io != NULL)
        fclose(io);

    return(retval);
#else
    _fatal("Not implemented!");  /* !!! FIXME */
    *buf = '\0';
    return(0);
#endif
} /* check_product_version */


int locate_product_by_identifier(const char *str, char *buf, size_t bufsize)
{
#if PLATFORM_MACOSX
    /* Ask LaunchServices to find product by identifier... */
    OSStatus rc;
    CFURLRef url = NULL;
    CFStringRef id = CFStringCreateWithBytes(NULL,
                                             (const unsigned char *) str,
                                             strlen(str),
                                             kCFStringEncodingISOLatin1, 0);

    rc = LSFindApplicationForInfo(kLSUnknownCreator, id, NULL, NULL, &url);
    CFRelease(id);
    if (rc == noErr)
    {
        int b = (int) CFURLGetFileSystemRepresentation(url, TRUE,
                                                       (unsigned char *) buf,
                                                       bufsize);
        if (b) b = 1;
        CFRelease(url);
        if ((b) && (strstr(buf, "/.Trash/")))
        {
            _fatal("It looks like your installation is in the Trash can."
                    " Please take it out of the trash first."
                    " If this is an old installation, please empty your"
                    " trash so we find the right one.");
            b = -1;
        } /* if */

        return(b);
    } /* if */

    return(0);
#else
    _fatal("Not implemented!");  /* !!! FIXME */
    return(0);
#endif
} /* locate_product_by_identifier */


int update_version(const char *ver)
{
#if PLATFORM_MACOSX
    const char *fname = "Contents/Info.plist";  /* already chdir'd for this. */
    char *mem = NULL;
    char *ptr;
    unsigned int fsize;
    int retval = 0;
    long writestart;
    long writeend;
    FILE *io = NULL;

    if ( !get_file_size(fname, &fsize) ) goto update_version_bailed;
    if ( (mem = malloc(fsize + 1)) == NULL ) goto update_version_bailed;
    if ( (io = fopen(fname, "r+")) == NULL ) goto update_version_bailed;
    if ( (fread(mem, fsize, 1, io)) != 1 ) goto update_version_bailed;
    mem[fsize] = '\0';

    ptr = find_info_plist_version(mem);
    if (ptr == NULL) goto update_version_bailed;
    writestart = (long) (ptr - mem);
    writeend = writestart + strlen(ptr);
    ptr = mem + writeend;
    if ( (fseek(io, 0, SEEK_SET) == -1) ) goto update_version_bailed;
    if ( (fread(mem, fsize, 1, io)) != 1 ) goto update_version_bailed;
    if ( (fseek(io, writestart, SEEK_SET) == -1) ) goto update_version_bailed;
    if ( (fwrite(ver, strlen(ver), 1, io)) != 1 ) goto update_version_bailed;
    if ( (fwrite(ptr, strlen(ptr), 1, io)) != 1 ) goto update_version_bailed;
    for (fsize = (writeend - writestart); fsize > 0; fsize--)
        if (fwrite(" ", 1, 1, io) != 1) goto update_version_bailed;

    retval = 1;

update_version_bailed:
    free(mem);
    if (io != NULL)
        fclose(io);

    if (!retval) _fatal("Can't update product's installed version.");
    return(retval);

#else  /* Regular old POSIX-compliant Unix... */

    /*
     * !!! FIXME: need some way to flag this install as updated...
     * !!! FIXME:  maybe just leave unimplemented?
     */
    _fatal("Not implemented!");
    return(0);

#endif
} /* update_version */


int calc_tmp_filenames(char **tmp1, char **tmp2)
{
    static char _tmp1[MAXPATHLEN];
    static char _tmp2[MAXPATHLEN];
    pid_t pid = getpid();
    snprintf(_tmp1, sizeof (_tmp1), "/tmp/mojopatch.tmp1.%d", (int) pid);
    snprintf(_tmp2, sizeof (_tmp2), "/tmp/mojopatch.tmp2.%d", (int) pid);
    *tmp1 = _tmp1;
    *tmp2 = _tmp2;
    return(1);
} /* calc_tmp_filenames */


static char *basedir = NULL;
static volatile int thread_alive = 0;

static void *spawn_thread(void *arg)
{
    static int rc;
    rc = system((char *) arg);
    thread_alive = 0;
    return(&rc);
} /* spawn_thread */


static SpawnResult spawn_binary(const char *cmd)
{
    int *ptr = NULL;
    int rc = 127;

#if !USE_PTHREAD
    pid_t pid = fork();
    if (pid == -1)
    {
        int e = errno;
        _fatal("fork() failed: %d (%s)", e, strerror(e));
        return(SPAWN_FAILED);
    } /* if */

    else if (pid == 0)   /* child process. */
    {
        ptr = (int *) spawn_thread((void *) cmd);
        if (ptr) rc = *ptr;
        exit(rc != 0);
    } /* else if */

    else
    {
        while (waitpid(pid, &rc, WNOHANG) == 0)
        {
            ui_pump();
            usleep(10000);
        } /* while */
        return((rc == 0) ? SPAWN_RETURNGOOD : SPAWN_RETURNBAD);
    } /* else */
#else
    pthread_t thr;

    thread_alive = 1;

    if (pthread_create(&thr, NULL, spawn_thread, cmd) != 0)
        return(SPAWN_FAILED);

    while (thread_alive)
    {
        ui_pump();
        usleep(10000);
    } /* while */

    pthread_join(thr, (void **) &ptr);
    if (ptr) rc = *ptr;
    return((rc == 0) ? SPAWN_RETURNGOOD : SPAWN_RETURNBAD);
#endif
} /* spawn_binary */


SpawnResult spawn_xdelta(const char *cmdline)
{
    SpawnResult retval;
    const char *binname = "xdelta";
    char *cmd = alloca(strlen(cmdline) + strlen(basedir) + strlen(binname) + 5);
    if (!cmd)
        return(SPAWN_FAILED);

    sprintf(cmd, "\"%s/%s\" %s", basedir, binname, cmdline);
    retval = spawn_binary(cmd);

    /* !!! FIXME: xdelta returns an unexpected value when making a delta. */
    /* !!! FIXME:  (we check the md5sums from all output anyhow. */
    if (retval == SPAWN_RETURNBAD) retval = SPAWN_RETURNGOOD;

    return(retval);
} /* spawn_xdelta */


/* you are chdir()'d to the directory with the patchfile here. */
SpawnResult spawn_script(const char *scriptname, const char *dstdir)
{
    char *cmd = alloca(strlen(scriptname) + strlen(dstdir) + 32);

    if (!file_exists(scriptname))
        return(SPAWN_FILENOTFOUND);

    sprintf(cmd, "./%s '%s'", scriptname, dstdir);
    return(spawn_binary(cmd));
} /* spawn_script */


char *get_current_dir(char *buf, size_t bufsize)
{
    size_t buflen = 0;
    if (getcwd(buf, bufsize) == NULL)
        return(NULL);

    buflen = strlen(buf) + 1;
    if (buflen <= bufsize)
    {
        *buf = '\0';
        return(NULL);
    } /* if */

    if (buf[buflen - 2] != '/')
        strcat(buf, "/");

    return(buf);
} /* get_current_dir */


static void find_basedir(int *argc, char **argv)
{
    const char *argv0 = argv[0];
    char buf[MAXPATHLEN];
    char realbuf[MAXPATHLEN];

    if ((argv0 != NULL) && (strchr(argv0, '/') != NULL)) /* path specifed? */
        strncpy(buf, argv0, sizeof (buf));
    else
    {
        char *ptr;
        char *envr = getenv("PATH");
        if (!envr)
            return;

        while (*envr)
        {
            ptr = strchr(envr, ':');
            if (!ptr)
                strcpy(buf, envr);
            else
            {
                memcpy(buf, envr, (size_t) (ptr - envr));
                buf[(size_t) (ptr - envr)] = '\0';
            } /* else */

            envr = ptr + 1;

            if (*buf == '\0')
                continue;

            strcat(buf, "/");
            strcat(buf, argv0);

            if (access(buf, X_OK) == 0)
                break;

            if (!ptr)
            {
                strcpy(buf, ".");  /* oh well. */
                break;
            } /* if */
        } /* while */
    } /* else */

    buf[sizeof (buf) - 1] = '\0';  /* null terminate, just in case. */
    if (realpath(buf, realbuf) == NULL)
        return;

    char *ptr = strrchr(realbuf, '/');  /* chop off binary name. */
    if (ptr != NULL)
        *ptr = '\0';

    if (realbuf[strlen(realbuf)-1] != '/')
        strcat(realbuf, "/");

    basedir = malloc(strlen(realbuf) + 1);
    strcpy(basedir, realbuf);

#if PLATFORM_MACOSX
    /* Chop off process serial number arg that the Finder adds... */
    if ( (*argc >= 2) && (strncmp(argv[1], "-psn_", 5) == 0) )
    {
        *argc = *argc - 1;
        argv[1] = NULL;

        /* Now that we know where xdelta will be, chdir out of AppBundle... */
        /* !!! FIXME: Fails if there are more than one of these in the string... */
        ptr = strstr(realbuf, "/Contents/MacOS/");
        if (ptr != NULL)
        {
            ptr++;  /* keep a '/' at the end of the string... */
            *ptr = '\0';
            chdir(realbuf);
        } /* if */
    } /* if */
#endif
} /* find_basedir */


int main(int argc, char **argv)
{
    int retval;
    find_basedir(&argc, argv);
    retval = mojopatch_main(argc, argv);
    free(basedir);
    return((retval == PATCHSUCCESS) ? 0 : 1);
} /* unixmain */

/* end of platform_unix.c ... */