minadbd/adb.c

/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define  TRACE_TAG   TRACE_ADB

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <stdarg.h>
#include <errno.h>
#include <string.h>
#include <time.h>
#include <sys/time.h>

#include "sysdeps.h"
#include "adb.h"

#include <private/android_filesystem_config.h>
#include <linux/capability.h>
#include <linux/prctl.h>

#if ADB_TRACE
ADB_MUTEX_DEFINE( D_lock );
#endif

int HOST = 0;

static const char *adb_device_banner = "sideload";

void fatal(const char *fmt, ...)
{
    va_list ap;
    va_start(ap, fmt);
    fprintf(stderr, "error: ");
    vfprintf(stderr, fmt, ap);
    fprintf(stderr, "\n");
    va_end(ap);
    exit(-1);
}

void fatal_errno(const char *fmt, ...)
{
    va_list ap;
    va_start(ap, fmt);
    fprintf(stderr, "error: %s: ", strerror(errno));
    vfprintf(stderr, fmt, ap);
    fprintf(stderr, "\n");
    va_end(ap);
    exit(-1);
}

int   adb_trace_mask;

/* read a comma/space/colum/semi-column separated list of tags
 * from the ADB_TRACE environment variable and build the trace
 * mask from it. note that '1' and 'all' are special cases to
 * enable all tracing
 */
void  adb_trace_init(void)
{
    const char*  p = getenv("ADB_TRACE");
    const char*  q;

    static const struct {
        const char*  tag;
        int           flag;
    } tags[] = {
        { "1", 0 },
        { "all", 0 },
        { "adb", TRACE_ADB },
        { "sockets", TRACE_SOCKETS },
        { "packets", TRACE_PACKETS },
        { "rwx", TRACE_RWX },
        { "usb", TRACE_USB },
        { "sync", TRACE_SYNC },
        { "sysdeps", TRACE_SYSDEPS },
        { "transport", TRACE_TRANSPORT },
        { "jdwp", TRACE_JDWP },
        { "services", TRACE_SERVICES },
        { NULL, 0 }
    };

    if (p == NULL)
            return;

    /* use a comma/column/semi-colum/space separated list */
    while (*p) {
        int  len, tagn;

        q = strpbrk(p, " ,:;");
        if (q == NULL) {
            q = p + strlen(p);
        }
        len = q - p;

        for (tagn = 0; tags[tagn].tag != NULL; tagn++)
        {
            int  taglen = strlen(tags[tagn].tag);

            if (len == taglen && !memcmp(tags[tagn].tag, p, len) )
            {
                int  flag = tags[tagn].flag;
                if (flag == 0) {
                    adb_trace_mask = ~0;
                    return;
                }
                adb_trace_mask |= (1 << flag);
                break;
            }
        }
        p = q;
        if (*p)
            p++;
    }
}


apacket *get_apacket(void)
{
    apacket *p = malloc(sizeof(apacket));
    if(p == 0) fatal("failed to allocate an apacket");
    memset(p, 0, sizeof(apacket) - MAX_PAYLOAD);
    return p;
}

void put_apacket(apacket *p)
{
    free(p);
}

void handle_online(void)
{
    D("adb: online\n");
}

void handle_offline(atransport *t)
{
    D("adb: offline\n");
    //Close the associated usb
    run_transport_disconnects(t);
}

#if TRACE_PACKETS
#define DUMPMAX 32
void print_packet(const char *label, apacket *p)
{
    char *tag;
    char *x;
    unsigned count;

    switch(p->msg.command){
    case A_SYNC: tag = "SYNC"; break;
    case A_CNXN: tag = "CNXN" ; break;
    case A_OPEN: tag = "OPEN"; break;
    case A_OKAY: tag = "OKAY"; break;
    case A_CLSE: tag = "CLSE"; break;
    case A_WRTE: tag = "WRTE"; break;
    default: tag = "????"; break;
    }

    fprintf(stderr, "%s: %s %08x %08x %04x \"",
            label, tag, p->msg.arg0, p->msg.arg1, p->msg.data_length);
    count = p->msg.data_length;
    x = (char*) p->data;
    if(count > DUMPMAX) {
        count = DUMPMAX;
        tag = "\n";
    } else {
        tag = "\"\n";
    }
    while(count-- > 0){
        if((*x >= ' ') && (*x < 127)) {
            fputc(*x, stderr);
        } else {
            fputc('.', stderr);
        }
        x++;
    }
    fprintf(stderr, tag);
}
#endif

static void send_ready(unsigned local, unsigned remote, atransport *t)
{
    D("Calling send_ready \n");
    apacket *p = get_apacket();
    p->msg.command = A_OKAY;
    p->msg.arg0 = local;
    p->msg.arg1 = remote;
    send_packet(p, t);
}

static void send_close(unsigned local, unsigned remote, atransport *t)
{
    D("Calling send_close \n");
    apacket *p = get_apacket();
    p->msg.command = A_CLSE;
    p->msg.arg0 = local;
    p->msg.arg1 = remote;
    send_packet(p, t);
}

static void send_connect(atransport *t)
{
    D("Calling send_connect \n");
    apacket *cp = get_apacket();
    cp->msg.command = A_CNXN;
    cp->msg.arg0 = A_VERSION;
    cp->msg.arg1 = MAX_PAYLOAD;
    snprintf((char*) cp->data, sizeof cp->data, "%s::",
            HOST ? "host" : adb_device_banner);
    cp->msg.data_length = strlen((char*) cp->data) + 1;
    send_packet(cp, t);
}

void parse_banner(char *banner, atransport *t)
{
    char *type, *product, *end;

    D("parse_banner: %s\n", banner);
    type = banner;
    product = strchr(type, ':');
    if(product) {
        *product++ = 0;
    } else {
        product = "";
    }

        /* remove trailing ':' */
    end = strchr(product, ':');
    if(end) *end = 0;

        /* save product name in device structure */
    if (t->product == NULL) {
        t->product = strdup(product);
    } else if (strcmp(product, t->product) != 0) {
        free(t->product);
        t->product = strdup(product);
    }

    if(!strcmp(type, "bootloader")){
        D("setting connection_state to CS_BOOTLOADER\n");
        t->connection_state = CS_BOOTLOADER;
        update_transports();
        return;
    }

    if(!strcmp(type, "device")) {
        D("setting connection_state to CS_DEVICE\n");
        t->connection_state = CS_DEVICE;
        update_transports();
        return;
    }

    if(!strcmp(type, "recovery")) {
        D("setting connection_state to CS_RECOVERY\n");
        t->connection_state = CS_RECOVERY;
        update_transports();
        return;
    }

    if(!strcmp(type, "sideload")) {
        D("setting connection_state to CS_SIDELOAD\n");
        t->connection_state = CS_SIDELOAD;
        update_transports();
        return;
    }

    t->connection_state = CS_HOST;
}

void handle_packet(apacket *p, atransport *t)
{
    asocket *s;

    D("handle_packet() %c%c%c%c\n", ((char*) (&(p->msg.command)))[0],
            ((char*) (&(p->msg.command)))[1],
            ((char*) (&(p->msg.command)))[2],
            ((char*) (&(p->msg.command)))[3]);
    print_packet("recv", p);

    switch(p->msg.command){
    case A_SYNC:
        if(p->msg.arg0){
            send_packet(p, t);
            if(HOST) send_connect(t);
        } else {
            t->connection_state = CS_OFFLINE;
            handle_offline(t);
            send_packet(p, t);
        }
        return;

    case A_CNXN: /* CONNECT(version, maxdata, "system-id-string") */
            /* XXX verify version, etc */
        if(t->connection_state != CS_OFFLINE) {
            t->connection_state = CS_OFFLINE;
            handle_offline(t);
        }
        parse_banner((char*) p->data, t);
        handle_online();
        if(!HOST) send_connect(t);
        break;

    case A_OPEN: /* OPEN(local-id, 0, "destination") */
        if(t->connection_state != CS_OFFLINE) {
            char *name = (char*) p->data;
            name[p->msg.data_length > 0 ? p->msg.data_length - 1 : 0] = 0;
            s = create_local_service_socket(name);
            if(s == 0) {
                send_close(0, p->msg.arg0, t);
            } else {
                s->peer = create_remote_socket(p->msg.arg0, t);
                s->peer->peer = s;
                send_ready(s->id, s->peer->id, t);
                s->ready(s);
            }
        }
        break;

    case A_OKAY: /* READY(local-id, remote-id, "") */
        if(t->connection_state != CS_OFFLINE) {
            if((s = find_local_socket(p->msg.arg1))) {
                if(s->peer == 0) {
                    s->peer = create_remote_socket(p->msg.arg0, t);
                    s->peer->peer = s;
                }
                s->ready(s);
            }
        }
        break;

    case A_CLSE: /* CLOSE(local-id, remote-id, "") */
        if(t->connection_state != CS_OFFLINE) {
            if((s = find_local_socket(p->msg.arg1))) {
                s->close(s);
            }
        }
        break;

    case A_WRTE:
        if(t->connection_state != CS_OFFLINE) {
            if((s = find_local_socket(p->msg.arg1))) {
                unsigned rid = p->msg.arg0;
                p->len = p->msg.data_length;

                if(s->enqueue(s, p) == 0) {
                    D("Enqueue the socket\n");
                    send_ready(s->id, rid, t);
                }
                return;
            }
        }
        break;

    default:
        printf("handle_packet: what is %08x?!\n", p->msg.command);
    }

    put_apacket(p);
}

static void adb_cleanup(void)
{
    usb_cleanup();
}

int adb_main()
{
    atexit(adb_cleanup);
#if defined(HAVE_FORKEXEC)
    // No SIGCHLD. Let the service subproc handle its children.
    signal(SIGPIPE, SIG_IGN);
#endif

    init_transport_registration();

    // The minimal version of adbd only uses USB.
    if (access("/dev/android_adb", F_OK) == 0) {
        // listen on USB
        usb_init();
    }

    if (setgid(AID_SHELL) != 0) {
        fprintf(stderr, "failed to setgid to shell\n");
        exit(1);
    }
    if (setuid(AID_SHELL) != 0) {
        fprintf(stderr, "failed to setuid to shell\n");
        exit(1);
    }
    fprintf(stderr, "userid is %d\n", getuid());

    D("Event loop starting\n");

    fdevent_loop();

    usb_cleanup();

    return 0;
}