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29 
30 #include "client/linux/crash_generation/crash_generation_client.h"
31 
32 #include <stdio.h>
33 #include <sys/socket.h>
34 #include <sys/types.h>
35 
36 #include <algorithm>
37 
38 #include "common/linux/eintr_wrapper.h"
39 #include "common/linux/ignore_ret.h"
40 #include "third_party/lss/linux_syscall_support.h"
41 
42 namespace google_breakpad {
43 
44 namespace {
45 
46 class CrashGenerationClientImpl : public CrashGenerationClient {
47  public:
CrashGenerationClientImpl(int server_fd)48   explicit CrashGenerationClientImpl(int server_fd) : server_fd_(server_fd) {}
~CrashGenerationClientImpl()49   virtual ~CrashGenerationClientImpl() {}
50 
RequestDump(const void * blob,size_t blob_size)51   virtual bool RequestDump(const void* blob, size_t blob_size) {
52     int fds[2];
53     if (sys_pipe(fds) < 0)
54       return false;
55     static const unsigned kControlMsgSize = CMSG_SPACE(sizeof(int));
56 
57     struct kernel_iovec iov;
58     iov.iov_base = const_cast<void*>(blob);
59     iov.iov_len = blob_size;
60 
61     struct kernel_msghdr msg = { 0 };
62     msg.msg_iov = &iov;
63     msg.msg_iovlen = 1;
64     char cmsg[kControlMsgSize] = "";
65     msg.msg_control = cmsg;
66     msg.msg_controllen = sizeof(cmsg);
67 
68     struct cmsghdr* hdr = CMSG_FIRSTHDR(&msg);
69     hdr->cmsg_level = SOL_SOCKET;
70     hdr->cmsg_type = SCM_RIGHTS;
71     hdr->cmsg_len = CMSG_LEN(sizeof(int));
72     int* p = reinterpret_cast<int*>(CMSG_DATA(hdr));
73     *p = fds[1];
74 
75     ssize_t ret = HANDLE_EINTR(sys_sendmsg(server_fd_, &msg, 0));
76     sys_close(fds[1]);
77     if (ret < 0) {
78       sys_close(fds[0]);
79       return false;
80     }
81 
82     // Wait for an ACK from the server.
83     char b;
84     IGNORE_RET(HANDLE_EINTR(sys_read(fds[0], &b, 1)));
85     sys_close(fds[0]);
86 
87     return true;
88   }
89 
90  private:
91   int server_fd_;
92 
93   DISALLOW_COPY_AND_ASSIGN(CrashGenerationClientImpl);
94 };
95 
96 }  // namespace
97 
98 // static
TryCreate(int server_fd)99 CrashGenerationClient* CrashGenerationClient::TryCreate(int server_fd) {
100   if (server_fd < 0)
101     return NULL;
102   return new CrashGenerationClientImpl(server_fd);
103 }
104 
105 }  // namespace google_breakpad
106